Book - On the Generation of Animals

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Aristotle - De generatione animalium

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This is an early uncorrected draft version of the text. Note the extensive use of Greek characters and footnotes requires much work to appear correctly here.

With An English Translation By

A. L. Peck, M.A., Ph.D.

Fellow of Christ's College, Cambridge, and University Lecturer In Classics

London, William Heinemann Ltd

Cambridge, Massachusetts, Harvard University Press


JUL 5 1949


praeceptori socio amico dedicat

A. L. P.


In reviewing Karl Bitterauf's book[1] in 1914, H. Stadler[2] described the Generation of Animals as " this still inadequately appreciated work of Aristotle's," and it must be confessed that his description is not yet out of date. It has, perhaps, been more appreciated by men of science than by scholars and philosophers ; but it has a strong interest for both classes of students. Its neglect by scholars and philosophers[3] is the more surprising, since it may, I think, be justly claimed that in this treatise Aristotle's thought is to be seen integrated as it is nowhere else ; for in reproduction, as understood by Aristotle, not only the individual is concerned but the cosmos at large : it is a business in which the powers of the universe are concentrated and united ; and it is the means whereby that eternity, with which, if he could have done it, God would have filled the whole creation from one end to the other, is attained so far as is possible by the creatures that are subject to decay ; indeed, these very beings, animals and plants,[4] have in Aristotle's view the best claim to the title of " being " (ovo-lo), a much better claim than the lifeless things out of which they are composed, or the objects made by human art : and therefore they merit to an exceptional degree the attention of the student of reality.

Perhaps philosophers, like the visitors who came to call on Heracleitus and found him in the kitchen, have felt embarrassed at finding Aristotle in his laboratory, and have thought it more dignified to wait until he came out ; failing to perceive that " there too gods are present.[5] And where the gods are, there too is beauty, however mean and however small the creature may be which is the subject of study - greater beauty than is to be found in the products of human skill ; for these are the workmanship of Nature, who does nothing idly or without purpose ; and in them too is to be found the activity of Soul, working through its instrument pneuma, which is the terrestrial counterpart of the celestial " quintessence," aither, the divine constituent of the heavenly spheres and of the stars ; in them, therefore. Form at its highest and Matter at its highest are seen operating in unison. For men of science, the Generation of Animals has a special interest, in that it is the first systematic treatise on animal reproduction and embryology, containing records of observations, marking out schemes of classification, and suggesting methods of dealing with problems, much of which has proved of permanent value ; indeed, Aristotle's work was not resumed until after the lapse of nearly two thousand years, and some of his observations were not repeated until comparatively recent times. Of this I shall have more to say presently.

Aristotle's Embryology

The De generatione animalium is the culminating portion of Aristotle's zoological works, of which the scheme may be exhibited as follows :

(requires formatting of original table)

I. Record of observations. Historia animalium.

II. Theory based upon observations (including also many observational data).

(a) treating of the " matter " of animals and the way in which it is arranged to subsers^e their various purposes ; i.e., their " parts," excluding those used in reproduction.

(b) De anima treating of the " form " of animals - i.e., Soul, and its " parts " or functions.

(c) Parva naturalia treating of the functions " common

De motu animalium to body and Soul," excluding

I animalium J reproduction.

(d) De generatione treatmg of the " parts " used in animalium reproduction, and of the reproductive functions (which are common to body and Soul).

The section (b) is necessary to the completeness of the scheme, but as it has given rise to a whole department of study, it is usually treated apart from the rest. Thus the main bulk of the zoological and biological works may be taken to consist of the three great treatises H.A., P. A. and G.A.[6] It was these which, through Latin translations made from the Arabic, were restored to the West by those who revived scientific studies at the beginning of the 13th century.

It is generally held that the zoological works were written during the second period of Aristotle's residence at Athens, when he was engaged in organizing systematic observation and specialized research, which produced, among other results, the collection of 158 constitutions of states (of which the Constitution of Athens, recovered at the end of the 10th century, is one), as well as the Historia animalium.[7] The zoological works have not been subjected to such minute criticism as, for instance, the Metaphysics and Politics, but, according to Jaeger, the H.A. shows clear traces of different authors, and he suggests that the work of observation was distributed among several persons from the outset. It is probable that some collection of material was made by Aristotle himself[8] between the two periods of his residence at Athens. But the real importance of these works is that they represent the first attempt in Europe to observe and describe in a scientific way the individual living object. Aristotle's method may be described as substantially the same as that of modern scientific workers : it is inductive-deductive, as opposed on the one hand to earlier (and later) methods of pure deduction from a priori premisses, and on the other hand to the Baconian method of almost exclusive induction. Aristotle often complains that his predecessors' work was marred by insufficient observation, and the importance which he himself attached to careful and thorough observation is apparent throughout the zoological treatises. Of particular interest in this connexion are his observations of the viviparous dogfish (Mustelus laevis), observations not repeated in modern times until the seventeenth century," and his knowledge of the hectocotylization of one of the tentacles in the Octopus ; the problem involved in the latter case has not yet been solved. Other problems raised by him have found their solution only in very recent years ; among them may be mentioned the breeding of eels and the anatomy of the hyena. His discussion of the reproduction of bees is a remarkable piece of analysis ; and here, again the facts are not yet fully ascertained. It is in connexion with this problem that Aristotle makes his well-known dictum : " But the facts have not yetv been sufficiently ascertained ; and if at any future time they are ascertained, then credence must be given to the direct evidence of the senses rather than to theories - and to theories too provided that the results which they show agree with what is observed." This, indeed, is the principle upon which his work is based : and although he is often forced to rely upon bare theories, it is only because he was unable to obtain experimental data - most insects, he regretfully remarks, are too small to be observed - in other words, it is only because he lacked the necessary apparatus. For his magnificent apologia (if such it can be called - protreptic would be a better word) on the subject of the study of natural history, the reader should refer to the passage in the first Book of the De partibus (ch. 5). Nevertheless it is probable that his theories, though they sometimes led him astray, did in fact often help him to adopt a correct general outlook, even if the detailed working out of them is erroneous. As examples of this we may quote his discussions and conclusions upon preformation and epigenesis and upon the time of sex-determination in the embryo.[9]

The main contributions of Aristotle to embryology, as judged from the viewpoint of a modern embryologist,[10] may be stated as follows :

  1. Following the lead of men like the author of the Hippocratic treatise π. γονης , Aristotle greatly extended the field of careful and accurate observation, and was thereby enabled to introduce for the first time the comparative method into embryology, and so to arrange the available data in an orderly way This is expressed, e.g., by his classification of animals according to their methods of embryonic development.
  2. He stated in the clearest terms the two rival theories of preformation and epigenesis, and decided in favour of the latter. He also laid down that the sex of the embryo was determined at the very beginning of its development.
  3. He clearly stated that generic characteristics precede specific characteristics in embryonic development, and, by his theory that the various faculties of Soul developed successively in the embryo, foreshadowed the modern theory of " recapitulation." By his observation that the " upper " parts of the embryo develop more rapidly than the " lower " parts he foreshadowed the modern doctrine of " axial gradients " (see 741 b 28, n.).
  4. He correctly understood the functions of the placenta and the umbilical cord ; and
  5. He prefigured (see 772 b 13 ff.) -with wonderful insight the cell-streams or morphogenetic movements which are fundamental in embryonic development during the period when the germ-layers are taking up their definitive positions.[11] His dynamic view of the origin both of normal structures and of monstrous deviations can be fully appreciated only in the light of modern knowledge of the great part played by movement, migration of cells, etc., in early embryonic development.

On the contrary side we must range such mistakes as these :

  1. The insect larva, which Aristotle regarded as the earlier stage of an egg, " an egg laid too soon," has in fact passed the embryonic stage.
  2. Observations of newly-castrated animals led him to regard the testes as of secondary importance.

With regard to his famous doctrine that the male Theory of supplies the Form and the female the Matter of the w°™ *?*^ embryo (see 729 a 11), some misunderstanding may easily arise. And also, with regard to his insistence upon the importance of the Final Cause, we find that modern scientific opinion, following the lead of Francis Bacon, who led the attack upon Formal and Final Causes, often tends to consider Aristotle's talk about these Causes as inferior to what he has to say on other matters. It is, however, open to question whether Aristotle would in fact have reached some of his most valuable conclusions apart from his insistence upon the pre-eminence of the Final Cause (any more than Harvey might have discovered the circulation of the blood unless he had tried to discover what was the Final Cause of the valves in the veins) ; and although Aristotle was of course ignorant of the existence of spermatozoa and of the mammalian ovum,[12] and although he considered that the menstrual fluid was the " matter " out of which the embryo was formed, it is not so certain that he was quite as wrong-headed as he is often said to be.

Before coming to a conclusion, we must consider what exactly Aristotle meant by Form and Matter in this connexion. In the first place, we must realize that the Form is not bare Form, nor is the Matter bare Matter : this, indeed, is a fundamental doctrine of Aristotle. Form is not found apart from Matter (that was a Platonic view),* nor is Matter found which is not to some extent " informed " ; and Aristotle can say (end of Met. H) that Matter in its ultimate stage is identical with Form (see Introd. § 17). At any rate, the Matter with which we are concerned in the generation of animals is far from being " uninformed." Like the " residue " contributed by the male, the " residue " contributed by the female is " concocted blood " ; and, since blood is the " ultimate nourishment " which maintains the upkeep of the body and its parts, both " residues " axe potentially the body of a H\infir creature of the same kind as that which produced them. Indeed, the only important difference between them is one of the degree of " concoction " which they have undergone, for the female, whose \ital heat is weaker, cannot carry the " concoction " of blood as far as the male can. But the female's " residue " (viz., the menstrual fluid) is, potentially, all the parts of the body ; and hence, too, it is, or contains. Soul potentially (this is merely another way of saying the same thing, because just as any actual h\'ing body must possess Soul, which is its Form, actually, so a potential U\-ing body must possess Soul potentially). That the female's " residue " does in fact possess Soul potentially is shown, says Aristotle, by the occurrence of wind-eggs in birds : these possess nutritive Soul, and up to a point they grow and " are fertile." The Matter, therefore, is " informed " to a high degree : and the only part of the Form which it lacks is sentient Soul. Hence, the meaning of the statement that " the male supplies the Form " can only be that the male suppUes that part of the Form known as sentient Soul : everything else, including nutritive Soul, can be, and is, suppUed by the female.

We may now go on to consider the " residue " contributed by^he male. Aristotle, as we saw, held that Form is not normally found apart from Matter (i.e., body) of some sort,[13] and besides that, according to him, action can only be exerted, change can only be brought about, by something that can come into contact with another thing. Therefore in any case something corporeal must be supplied by the male as well as Form, and this is of course the substance which carries the (potential) Form : it is the substance with which the sort of Form known as Soul is specially and regularly connected, and in which it resides, viz., connate pneuma. This pneuma, which is thus present in the semen, is charged with the " movements " proper to Soul, including (in the case of the male) the " movements " proper to sentient Soul ; and these " movements," when given the right material to work upon (viz., material which is potentially an animal of the right kind) and the right conditions, are able to produce an animal of the same kind as that which they would have produced or maintained in the male parent even if the blood in which they were originally present had not undergone the further stage of being concocted into semen.

Hence it is clear that fundamentally the contributions of both parents in generation are identical ; both are potentially a living animal of a certain kind, and this involves that both possess the living animal's Form, viz., its Soul, potentially ; and the only difference between them is that the male's contribution possesses also sentient Soul potentially.

At the same time, this is an important difference, and makes itself apparent in the difference of bulk between the two : the female's is large in bulk, the male's is small. And this difference of bulk is accounted for by the fact that the female's is less " concocted " than the male's - it is less concentrated. Further, the only Matter that the semen need contain is a sufficient amount to transmit the " movements " to the female's residue, and once this has been done - that is to say, once the embryo or rather its heart has been " constituted," once, it has been given its " principle " and has the power to grow - then the " body " of the semen can " evaporate," for the Matter which provides the embryo with its wherewithal for growth is of course supplied by the female parent.

As a final word on the subject we may recall that, in addition to what we have already found Aristotle saying about the identity of Matter and Form in the long run, he finds no greater difficulty in identifying (^iVis with Matter than he does in identifying it mth Form or with the Motive Cause and the Final Cause (see Introd. § 14', end) ; and when all the attributes have been ascribed to Matter which Aristotle ascribes to it in spontaneous generation (see App. B § 17, additional note), there is very little more left for it to desire.

I have not thought it necessary to call attention to all Aristotle's mistakes, partly because of lack of space, but chiefly because it would serve no really useful purpose. Nor have I given an account of modern embryological theory. My main object has been to ensure that the reader shall be able to find out what Aristotle said, and to secure that Aristotle shall get neither credit nor discredit for things which he did not say. In a treatise such as G.A., this means that fairly copious footnotes are necessary,[14] and as a further help to the reader I have provided not only a full account of Aristotle's technical terms (which gives an opportunity for explaining a good deal of the framework of his thought), but also, in the Appendix, accounts of his theory of the universe and movement (without which parts of Books II and IV cannot be understood) and of the functions of (Σ……insert greek here)[15] an essential factor in his doctrine of generation. On Aristotle the principle that, for the most part, Aristotle is his own best interpreter, these accounts are compiled almost entirely from passages taken direct from Aristotle's own treatises. In reading Aristotle's scientific works, it is important not only to recognize how great were the advances which he himself made in natural history, both in - practical observation and in theory, but also to remember that his work was a continuation and an expansion of what had been begun by previous scientific workers.[16] Those to whom he most frequently refers by name are three : Anaxagoras, Empedocles, and Democritus, besides several references to theories which can be traced in the Hippocratic treatises[17]; and the fact that he often quotes them in order to disagree with them should not lead us to underrate their achievement. It is not possible here to give any adequate account of these predecessors of his, and for details about them the reader must be referred to the standard works on the early scientists and philosophers and to other works of reference.[18] Alcmeon, to whom also he refers, is an important figure, since it was he, apparently, who originated the famous doctrine of " passages " (or " pores," iropoi) in connexion with sensation, and held that the brain was the common sensorium, in which belief he was followed by Hippocrates and Plato, whereas Empedocles and Aristotle reverted to the older view that the heart is the central organ of sensation. Alcmeon also treated systematically of the special senses, in particular that of sight. Other theories of his mentioned by Aristotle may be found by reference to the Index.

Anaxagoras of Clazomenae, the last great name in the Ionian philosophic succession of Asia Minor, is well known for his theory that voi«s is responsible for the order of the universe as a whole, just as it is for the order which is to be discerned in living creatures, and for his remarkable theory of matter, which he constructed specially \\'ith a \'iew to accounting for generation and growth. I have treated fully of this elsewhere.[19]

Empedocles of Acragas, a striking figure, was a slightly younger contemporary of Anaxagoras, and was renowned as a politician, religious teacher, rhetorician, philosopher, and physician : he was the founder of the " Italian " school of medicine. Considerable portions of his poems on Nature and Purifications are extant. He adopted, perhaps formulated, the doctrine of the four E!,lements, which really means (see TT. apxaii]<i n]TpiKrj<i, chh. 13 fF.) that he selected, as especially important, four out of the many substances already recognized as fundamental in traditional Gi-eek medical theory (see Introd. § 24).

Democritus of Abdera, the follower of Leucippus, is best known for his advancement of the atomic theory originated by his master. Abdera is not far from Aristotle's birthplace, Stageira, and Aristotle seems to have been specially interested in Democritus.[20]

The following table will indicate roughly the dates of these early scientists :

Alcmeon of Crotona, probably a Pythagorean and a pupil of Pythagoras himself (he was " a young man in Pythagoras' old age "). Pythagoras is said to have gone to Italy in 529 b.c. and to have lived at Crotona for twenty years. Alcmeon was probably active, therefore, about 510-480.[21]

Anaxagoras of Clazomenae. Born about 500 b.c, died 428. Lived at Athens c. 480-450, and was a friend of Pericles. Mentioned by Socrates in a well-known passage in Plato's Phaedo.

Empedocles of Acragas (Agrigentum) in Sicily ; c. 494-434.

Democritus of Abdera in Thrace ; c. 460-370.

It is not possible to assign exact dates for all the treatises in the Hippocratic collection ; indeed they cannot all be ascribed to a single author, but one of the most important, the 77. dp;^at7/s IrjrpiKyjs, refers to Empedocles as having introduced new-fangled ideas into the long established science of medicine (ch. 20). Other treatises relevant to our subject are the tt. depoyv v6dro}v tottwv, the tt. Suii't-qs, and the ~. yoi'rjs Kal IT. (insert greek here). All of these are most interesting and will repay study. The last named in particular is the work of a most active and enterprising man, always ready to experiment and to record his results and to make use of them.

It should of course be remembered that although Aristotle introduced much new technical terminology and sometimes gave new content to what already existed, many of the terms which he uses were the common property of scientific writers, among them being such important ones as the following : Srva/zis, Kpaa-fi, (TvvT'i^yiJ.a, a-vfj.iJ.€Tpiu, €?8os, Trver/xa and the like. I have attempted to trace the development of one such term in my account of Si'm/xts (Introd. §§ 23 if.).

It is not possible here to say much about Aristotle's successors, but it is necessary to say enough to emphasize the important influence which they have had in the history of science. Hieronymus Fabricius ab Aquapendente (1537-1619) knew and admired Aristotle's work on embryology, and what is more, himself carried out further important observations on the same subject. His brilliant successor, William Harvey (1578-1657), was a student of Aristotle, and much of his inspiration came from Aristotle's works. Harvey was indeed the first to make any substantial advance in embryology since Aristotle himself. In other departments of study, however, during the 17th century, the authority of Aristotle and the scholastic doctrine with which he was identified were being combated in the name of " freedom," and so it came about that the zoological works too, which had been brought to light by the " dark " ages, were allowed to pass back into oblivion by the age of enlightenment. It was not until the end of the 18th century that they were rediscovered for the second time by Cuvier (1769-1832) and members of the Saint-Hilaire family.

Early Translators

Early Lack of space forbids reprinting here the account translators, Which I gave in the Introduction to P. A. of the fascinating history of the early translators of Aristotle's zoological works, and I must be allowed to • refer the reader to that volume (pp. 39 ff.) for details and other references. A mere list of the four most important translations must here suffice :

(1) The physician Ibn al-Batriq translated the H.A., P. A. and G.A. into Arabic at Bagdad during the time of the Caliphate of al-Mamun (813-833), son of Harun al-Rashid. There is a MS. of an Arabic translation, probably Ibn al-Batriq's, in the British Museum[22] ; and there can be little doubt that this is the translation from which Michael Scot made his Latin version.

(2) Michael Scot translated H.A., P. A. and G.A. into Latin from the Arabic at Toledo. This translation was finished before 1217.

(3) William of Moerbeke translated the zoological works into Latin from the Greek, at Thebes, in or before 1260.

(4) Theodore of Gaza began at Rome in 1450 to make translations of Aristotle and other Greek authors. His translation of the zoological works of Aristotle is dedicated to Pope Sixtus IV, and this soon became the standard Latin version. It is printed in the Berlin edition of Aristotle.

The Text

It soon became clear that for the purpose of translation it was necessary to make a working version of the Greek text, and to this end I made my first draft with the Berlin edition, Aubert and Wimmer's edition, and Platt's translation and textual emendations before me. Next, I transcribed suspected passages with their contexts from the mss. of Scot's version, in order to give them fuller consideration. Then, having incorporated a large number of changes into the text, some of them my own, I took into consideration the work of Bitterauf and others. In some cases I found that the same emendation had been proposed by two or more scholars independently, and also that some of these emendations were confirmed by Scot. Finally, I found it necessary to transcribe further portions of Scot's version.

I do not wish to claim more for the text here offered than that it is a better text than any hitherto available. I have done my best with the data at my disposal, but I am well aware that many passages yet remain to which I have not been able to offer any satisfactory solution. When I have accepted the reading of Bekker's criticus. gfji^^JQf,, I have not normally given the in^ss. variants. These will be found in Bekker's apparatus. Corrected reports of mss. readings as given by Susemihl and Bitterauf I have distinguished by an asterisk ; the other readings are as reported by Bekker[23] (sometimes confirmed by Bitterauf). Every departure from Bekker's text is recorded. The text has been reparagraphed throughout, and ™™ â– in many places the punctuation has been corrected. The following manuscripts[24] are cited for the Greek text :

Z Oxoniensis Collegii Corporis Christi W.A. 2. 7 ( = Coxe 108). Late 12th century. Presented to the College by Henry Parry, P'ellow, in 1623. It contains P. A., I. A., G.A., some of the Parva Naturalia, and De spiritu. G.A. begins f. 74^, and ends f. \QV, but this page is identical with 62^. The MS. is confusedly bound, and some passages it has lost altogether.[25]

S Laurentianus Mediceus 81, 1. Written in different hands, some of the 12th, some of the 13th century. G.A. is written in a 12th century hand.

P Vaticanus graecus 1339- Great variation of opinion upon the date of this manuscript has been expressed by various scholars. Some date it 12th century, others 15th.

Y Vaticanus graecus 261. 14th century (Btf.).

The following are cited for a few places only :

m Parisinus 1921. 1-lth century. In this ms. G.A. is accompanied by the commentary of Michael of Ephesus.

O<Michael Scot’s translation</ref> Riccardianus 13. Late 14th century. E Parisinus regius 1853. Written in various hands, from 10th to 15th century. G.A. is in a 15th century hand.

The following manuscripts of Michael Scot's transation are to be found in this country : translation.

Cambridge, University Library li. 3. 16. Cambridge, University Library Dd. 4. 30. Cambridge, Gonville and Caius College 109Oxford, Merton College 278. Oxford, Balliol College 252. London, British Museum Royal 12. C. XV. London, British Museum Harl. 4970.

All these are of the 13th or 14th century. I have seen all these mss. of Scot's translation, but chiefly owing to present conditions I have worked with the two first mentioned only.[26]

The chief mss. cited by Bekker for G.A. (namely, The text: PSYZ) are identical with four of the six cited by him for P.A.[27] Some years ago, when working on P. A. for the Loeb edition, my examination of the ms. Z at several places led me to state {P. A. Introd. p. 46) that a more reliable collation of the chief mss. than Bekker's apparahis criticus afforded was clearl)' needed. This view is amply confirmed by K. E. Bitterauf, who has in fact undertaken such a collation for G.A. (see below), and he shows that there are several errors and misleading reports on every page in Bekker's apparatus, (h) the A comparison of the text of P. A. exhibited by our "'3^i^[*P^ Greek mss. with the translation of Michael Scot showed me that the former had all suffered identical corruptions or losses (or both) in certain passages {e.g., P. A. 684 b 22 ff.), by which the Greek ms. from which Scot's Arabic original was translated had not been affected ; and I found exactly the same when I came to work oh G.A. (see, e.g., 722 a 20, 766 b 35). My conclusion about the common origin of our Greek MSS. is also supported by Bitterauf, who comes independently to the conclusion, based exclusively upon a study of the Greek mss., that they are all derived from a single archetype, Which, in his opinion, contained a number of variant readings. Modorn This brings us to a consideration of the ms. tradition X-^l)*Z of G.A. After the publication of Bekker's Berlin edition in 1831, very little work was done on the mss. of G.A. for about eighty years. Bussemaker, who edited G.A. in the Didot edition (Paris, 1854), cites many readings from the two Paris mss. E and m, and several times quotes the authority of William of Moerbeke, less frequently that of Michael Scot, and in a few cases quotes their Latin versions. Aubert and Wimmer, in their Leipzig edition published in 1860, took into account throughout the commentary of Michael of Ephesus and Gaza's Latin translation, but they too reUed upon Bekker for the mss. readings. The first to go back again direct to the mss. was F. Susemihl,[28] at whose request in 1885 By water and Vitelli inspected a number of selected places in Aristotle's zoological works in the mss. Z and S respectively, and of these fourteen are places in G.A. The majority of these, however, are of minor importance. A really serious attempt to revise the text throughout on the basis of a new collation of the mss. was made about 1913 by K. E. Bitterauf in preparation for a new Teubner edition, which however was never published.[29] In all, Bitterauf enumerates 31 mss. containing G.A., and of these he collated three in full himself from photographs (Z, Y and E), and a single selected Book (not the same Book in each case) in eight more (of which m was one). He also had at his disposal collations of seven others, of which five were apparently collated direct by Hugo Tschierschky (these include S and 0*5, and another ms. called /5 which contains only a very small part of the beginning of G.A.) and the remaining two (one of which is P) were collated by L. Dittmeyer from photographs. Five others were collated (apparently from photographs) by Bitterauf sufficiently to establish their character ; of the remaining eight he gives no report on the character of their text. The upshot of Bitterauf 's work is to show that Bekker was right in basing the text upon PSYZ, and that although the most faithful witness to the original text is Z, with P a good second, no ms. has a monopoly of the truth, since their common descent gives them all a fair chance of preserving a good reading, just as it has undoubtedly ensured, as I mentioned above, that they have all failed to preserve the text in certain passages. With regard to the defective nature of Bekker 's apparatus, the corrections which Bitterauf gives are of value primarily in determining the comparative trustworthiness of the mss. rather than in yielding substantial improvements of the text[30] ; but there are a good many places where they do make an improvement possible, and all the suggestions which Bitterauf makes for so doing I have carefully considered, and many I have adopted.[31] When the changes indicated are of a minor character, for instance those affecting merely the order of words, I have not always felt it necessary to alter Bekker's text, though it might be held that ceteris paribus Z's reading should be preferred.

Bitterauf does not appear, at any rate from what he has pubhshed, to have en\-isaged the existence of deep-seated corruptions or serious losses from the text. The furthest he ventures along this path is to suggest that alfia and a-dp^ should be ^^Titten t^\•ice instead of once at 722 b 34, and that kuI dioioy has dropped out at 74-6 a 34 ; but the latter suggestion, which is certainly right, is taken over from Bussemaker. However, that loss of phrases and corruption of the text have occurred is sometimes clear from intrinsic evidence, and loss can sometimes be proved bv the sur\-ival of the original words in M. Scot's translation.

Apart from re-examination of the mss., proposals to Conjectural improve the text by conjectural emendation have emendation. been made by the following : (1) Wimmer, who was responsible for the textual work in Aubert and Wimmer 's edition of 1860, made a number of conjectures, some of which he incorporated in the text and others he printed in the footnotes. Many of them are undoubtedly correct, and some I have found are supported by Scot (though I have no reason to think that Wimmer himself was aware of this).

(2) F. Susemihl,[32] beside the work which he did on the MSS., dealt with the question of duplicate recensions in the text, and also that of interpolations by commentators, and made a number of conjectural emendations.

(3) Arthur Platt, in his translation of G.A. in the Oxford Translations of Aristotle, published IQIO, suggests a number of emendations, many of which have been adopted in the present text ; and some of these, again, I have found to be confirmed by Scot's translation, though Platt himself was unaware of this. Platt also detected many corrupt places and misplaced passages or interpolations.

(4) Bitterauf himself puts forward about ten conjectural emendations in addition to his other suggestions for improving the text, but few of them are of major importance.

A few suggestions for emendation were made by :

(5) H. Bonitz,[33] en passant, as asides to his treatment of passages in other works of Aristotle, and by

(6) H. Richards[34] ; some of these will be found recorded in their proper places.

Single small emendations are proposed by M. Hayduck[35] and E. Zeller.[36] A few are proposed by H. Diels and one by W. Kranz.[37] J. G. Schneider, too, in his edition of H.A. (1811) made some suggestions for improving the text of G.A. based partly on the Latin versions, but most of his work is superseded by Bekker's edition. Some passages are also discussed by J. Zahlfleisch.[38]

Platt seems to have known nothing of Bonitz' or Susemihl's work, and Bitterauf seems to have known nothing of Platt's work. Bitterauf refers to and quotes Susemihl's article, but puts forward as an original conjecture one which Susemihl had already made (756 a.24).

Several emendations have been put forward by various scholars, beginning vdth Schneider, on the strength of Gaza's Latin version, others on that of WilUam of Moerbeke. As a contribution to the projected Teubner edition of G.A., Dittmeyer[39] published in 1915 the first part of William's version (up to 737 b 5). Although this version gives support to two small emendations already adopted in my present text (at 733 b 34. and 734.* b 18), and at 775 a 11 ff. (teste Schneider) preserves a passage which our Greek Mss. have lost, in general it does not yield anything that is independent of our existing Greek mss. and is, as Dittmeyer himself agreed, of little value for the restoration of the text.[40]

The case is far different with Michael Scot's version. This was made about 1217, not from a Greek text, traslation. but from an Arabic translation, itself made at the beginning of the 9th centurv, and hence the Greek text involved must have been considerably older than any of our present mss. and a priori may have represented an independent tradition of the text : indeed, my examination of Scot's version has proved this to be so. Dittmeyer quotes Schneider's opinion (IV. xxxvii) that Scot's version is of httle value for restoring the text, but it is obvious that neither he nor Bitterauf[41] had troubled to read Scot's version of G.^. beyond the tiny fr a.gmentH( frustula, Dittmeyer's own word) quoted by previous scholars. Against this we have the opinion of G. Rudberg,[42] had made a considerable study of it in connexion with H.A. and published its version ot H.A.'X. in extenso, that there is no doubt of its critical value for rectifying the text ; and this judgement I can confirm from my own experience. Naturally, the circumstances dictate that proper safeguards must be adopted in using it for correcting the Greek text ; and what these are can be learnt only by fairly wide experience of the version itself; any judgement given,[43] either for or against, without this experience as a foundation is worse than useless. My own method has involved the transcription of a large number of continuous passages from the mss. of Scot's version, containing places which some previous editor or I myself had already felt for some reason to be doubtful ; and the pertinent parts of these, where they have anything to contribute, I have given in the apparatus. Scot's version sometimes confirms conjectures previously made, sometimes it confirms the suspected corruption of the text either through glosses or otherwise, and in these cases may suggest means for remedying the trouble. Often it clearly confirms the existing text ; sometimes it gives no clear indication, and sometimes it simply omits the passage. I consider the time and trouble spent upon Scot's version as well spent.

The Greek commentary of Michael of Ephesus (formerly attributed to Johannes Philoponus), 11-12th century a.d., has been edited by Michael Hayduck (Berhn, 1903), but it is of Uttle use for textual criticism.

Apart from manuscript errors of the usual kind, and losses of words or phrases due to homoioteleuton, etc., which will be found noted in their places where they can be detected, the chief points of note in the text of G.A. may be classed as follows :

A. Paragraphs, occasionally sentences only, which obviously interrupt the line of argument or are superfluous to it. Of these, some seem to be

(a) genuine Aristotelian material, but misplaced, perhaps incorporated at the wTong place, or perhaps originally supplementary notes never intended to stand in the text ;

(b) alternative versions of matter already in the text ;

(c) extraneous matter, derived from commentators' remarks and wrongly incorporated in the text {e.g., 724. b 12-23, 726 b 25-30).

These are often found at the beginning or end of a section, which suggests that they were originally appended in the margin. There is no need to give a full list of these passages, but a list of (a) and (6) may be useful. They are : 715 b 26-30 ; 718 a 27-34. ; 726 a 16-25 ; 732 a 1223 ; 737 a 35-b 7 ; 760 a 26-27 ; 760 b 2-8 ; 760 b 33- 761 a 2 ; 781 a 21-b 6.

B. Short passages, often only a few words, derived from glosses which have either (a) supplanted the text or (b) been incorporated into it.

There are a great many short interpolations, and I have frequently omitted them from the translation.

Modern Editions

1. The Berlin edition of Aristotle, by Immanuel Bekker. Vol. I includes G.A., pages 715-789 (by the columns and lines of which the work is normally cited). Berlin, 1831.

1a. The Oxford edition (a reprint of the preceding). Vol. V includes G.A. Oxford, 1837.

2. One-volume edition of Aristotle's works, by C. H. Weise.[44] Leipzig, 1843.

3. The Didot edition. Edited by Bussemaker. Vol. III includes G.A. Paris, 1854.

4. The Leipzig edition. Vol. Ill contains G.A., edited and translated into German by H. Aubert and Fr. Wimmer. Leipzig, 1860. Contains a useful introduction, table of animals, and Greek index.

Translations Only


5. Thomas Taylor. English translation of Aristotle in ten volumes. Vol. IV contains G.A. (pp. 243 fF.). London, 1808.

6. J. Barthelemy-Saint-Hilaire.[46] Introduction, French translation of G.A. and notes. In two volumes. Paris, 1887.

7. Arthur Platt. In the Oxford series of translations of Aristotle. Vol. V contains Platt's translation of G.A., >vith notes. Oxford, IQIO.

The Translation

In translating G.A. I have followed two main Principles principles, with the aim of presenting Aristotle as faithfully as possible to the English reader :

  1. I have attempted to translate G.A. into EngUsh, and therefore I have not felt obhged to write in Aristotelian, or even in Greek, idiom. Hence, for example, I have not uniformly translated yap by " for," Kat by " and," or Se by " but " : unfortunately, it is still necessary to point out, even to learned reviewers, that there is a better way than that of " stock " translations ; and a translator is not automatically a traitor if he sometimes omits (yap insert greek here) - as the most idiomatic way of translating it,
  2. Technical terms, on the other hand, must whenever possible be uniformly represented by an invariable term in the English. Sometimes this rule must be broken, either (a) because the original term has a variety of meanings (e.g., Svrapii), sometimes (6) because there is no English word which will do (e.g., crvvurTavaL). I have avoided modernizing Aristotle's terms, so as to avoid misleading any modern readers who may have but little Greek ; and on the positive side I have given a full account of many of these terms in the Introduction. In my opinion, it is essential that the Introduction be read before undertaking any study of the treatise itself.

The purpose I have had in mind, therefore, is to ensure so far as possible, that the reader shall not have the unnecessary difficulty of " translators' English " to overcome, but shall be able to give his full attention to Aristotle's thought and argument : this is especially necessary in the present case, where we are dealing primarily with a scientific treatise. My aim has not been to paraphrase Aristotle or to " improve " upon him, but to represent what he says as closely and as faithfully as possible in English. ofannot.1- Since, however, G.A. is not intelligible, even to a Greek scholar, without some familiarity with Aristotle's general thought and some of his main doctrines, I have provided an outline of these in the Introduction and in the Appendix ; and in the footnotes I have given many cross-references to other passages in G.A. and other treatises : attention is also called to points of special interest. One of these, which I think has not hitherto been noticed, may be mentioned here : the possibility that there is an allusion at 735 b 17 to an early process of oil-flotation in ore-dressing.

The Index is not intended to be exhaustive, forms a supplement to the Contents-Summary (p. Ixxi) and the Introduction. Particular attention is given to certain key-phrases and ideas. It covers the Preface, Introduction, footnotes and Appendix as well as the translation.

A glance through the Index may help a reader with special interests to find the passages most relevant to his subject : e.g., the entn' " causation, mechanical " gives a reference to the passage, specially interesting to modern readers, which compares the development of the embryo to the action of automatic puppets.

A number of books which the student of Aristotle's Additional zoological works will find useful are mentioned in the gj. footnotes throughout the volume ; to them may be added the following :

F. J. Cole. Early Theories of Sexual Generation, Oxford. 1930.

C. H. Haskins, Studies in the History of Medieval Science, ed. 2. Cambridge, Mass., 1927.

T. E. Lones, Aristotle's Researches in Natural Sderwe, London, 1912.

A. W. Mever, The Rise of Embryology, Stanford, Calif., 1939.

C. Singer, Studies in the History and Method of Science, Oxford, 1921.

C. Singer, Greek Biology and Greek Medicine, Oxford, 1922.

H. B. Torrey and F. Felin, Was Aristotle an Evolutionist ? in Qu. Rev. of Biology (Baltimore), XII (1937), 1-18.

D'Arcy W. Thompson, Essay on " Natural Science " in The Legacy of Greece, Oxford, 1924.

S. D. Wingate, The Medieval Latin Versions of the Aristotelian Scientific Corpus, London, 1931.[47]

In addition to Ross's Aristotle and Jaeger's Aristotle (English translation by R. Robinson) and Diokles von Karystos, which are of special importance, the following bear upon certain subjects dealt with in G.A. :

P. Bochert, Aristoteles' Erdkunde von Asien und Lihyen, 1908, and

H. Diller, Wander arzt und Aitiologe, 1934 (for the effects of climate, etc.).

H. Meyer, Das Fererbungsproblem bet Aristoteles, in Philologus, LXXV (1919), 323 ff.

M. Wellmann, Fragmentsammlung der sikelischen Arzte, 1901.

The following more general technical works may also be mentioned :

J. S. Huxley and G. R. de Beer, The Elements of Experimental Embryology, Cambridge, 1934.

H. G. Miiller-Hess, Die Lehre von der Menstruation vom Begitm der Neuzeit bis zur Begriindung der Zellenlehre, Abhandl. z. Gesch. d. Naturw. u. Med., 1938, no. 27.

Aute Richards, Outlive of Comparative Embryology, New York, 1931.

D'Arcy W. Thompson, Grotvth and Form, Cambridge, 1917 (new ed., 1942).

P. Weiss, Principles of Development, New York, 1939

The standard work on its subject is Geschlecht und Geschlechter im Tierreiche, by Johannes Meisenheimer (1921).

Preface Notes

  1. Der Schlitssteil der aristotelischen Biologie; see below, p. XXV.
  2. In Berliner Philologische Wochenschrift (1914), p. 833.
  3. Among the less learned, however, the outstanding achievement of Aristotle in this branch of study has been for at least the last three centuries acknowledged by the title of the popular handbook known as Aristotle's Masterpiece.
  4. Aristotle's strong interest in plants is shown by the large number of references to them in G.A. ; see Index.
  5. See P. A. I. 645 a. 20 ff.
  6. For abbreviations, see p. Ixxvi.
  7. See W. D. Ross, Aristotle, and W. W. Jaeger, Aristotle.
  8. See D. W. Thompson, prefatory note to translation of H.A., p. vii. viii
  9. For a useful general estimate of Aristotle's work, see E. S. Russell, The Interpretation of Development and Heredity (1930), pp. 11-24.
  10. See, e.g., J. Needham, A History of Embryology (1934), pp. 36 ff.
  11. See J. Needham, Biochemistry and Morphogenesis {1942), where also the most modern views on the origin of monsters will be found. On this subject, C. Dareste's Production artificielle des monstruosite's (1877) is still the classical work.
  12. Discovered by K. E. von Baer 5 there is a complete facsimile of tils fundamental memoir De ovi mammalium et hominis genesi (Leipzig, 1827) in Sarton's his, XVI (1931), 313 ff.
  13. See Introd. § 42. An exception is rational Soul, which is not the Form of any body (§ 44), but this is a separate question, and in any case affects man only. We must also except the 55 immaterial unmoved movers, which Aristotle posits in the Metaphysics (1074 a) to account for the movements of the planets.
  14. See also p. xxxiv.
  15. The doctrine of ΣΙΙ was older than Aristotle (see Jaeger ; references given Introd. § 46, n.), but in this volume I am concerned only with Aristotle's presentation of it.
  16. Aristotle calls them collectively (φ ……insert greek here) or (φe……insert greek here) " physiologers," i.e., writers on " Nature," " natural " scientists. See 741 b 10, n.
  17. There are also, of course, references to theories stated by Plato, to which attention is called in the notes ; but Plato is not mentioned bv name. See also K. Prachter, Platon Praformist? in Philologus, LXXXIII (1937), 18-30.
  18. e.g., J. Burnet, Early Greek Philosophy ; see also for Hippocrates, W. H. S. Jones (Loeb ed.) ; for Alcmeon, J. Wachtler, De Alcmaeone Crotoniata (1896) ; and M. Wellmann, Die Schrift it. Iprjs vovaov, in Archiv f. Gesch. der Med. XXII (1929), 290-31:?. For a conspectus of ancient embryology, H. Balss, Die Zeugungslehre u. Embryologie in der Antike, in Quellen u. Studien zttr Gesch, der Naturvc. u. der Med. V (1936), 193-374.
  19. C.Q. XXV (1931), 27 ff., 112 IF.; see also G.A. 723 a 7.
  20. For further details about Democritus, see C. Bailey, The Greek Atomists and Epicurus.
  21. According to W. A. Heidel, however, Hippocratic Medicine (1911), 43, and American Journal of Pliilology, LXI (1940), 3 ff., Alcmeon's floruit should be put considerably later, say at 450 b.c.
  22. B.M. Add. 7511, 13th-14th century ( = Steinschneider B.M. 437). I have seen this ms. Judging from the passages which Dr. R. Levy kindly read for me in this ms., Scot's Latin version is a close translation from the Arabic. This is confirmed by the fact that the contents-preface which is found prefixed to Scot's translation corresponds exactly with the preface which precedes the Arabic version in this ms. (see B.M. Catalogus codicum tnanuscriptorum orientalium, p. 215).
  23. A few (for m and E) are as reported by Bussemaker.
  24. For further details, see Bitterauf (below, p. xxv), Dittmeyer, H.^l. (Introd.), Jaeger, M.A. and LA. (Introd.), etc.
  25. 738 b 1 ^€Xt[Iovos ... 740 a 7 to] yevonevov ; and 760 a 13 TTcos [r) yeveais . . . 760 b 27 /x€v| cAcittco, the latter passage having been supplied by a later hand.
  26. Lists of MSS. of William of Moerbeke's translation will be found in G. Rudberg, Textstudien zur Tiergeschichte des Aristoteles (1908), and L. Dittmeyer (see below, p. xxix).
  27. Of the other two, U does not contain G.A., and in E G.A. is written in a later hand.
  28. Kritische Studien zti den zoologischen Schri/ten des Aristoteles, in Rhein. Mus. XL (1885), 563 ff., and a very convenient summary of his proposals there made in Bursian, XLII, 345 f.
  29. But he published some of his results in two preliminary pamphlets : (1) Der Schlussteil der arlstotelischen Biologie : Beitrage zur Textgeschichte und Textkritik der Schrift " De generatione animalium." (Wissenschaftliche Beilage zum Jahresbericht des kgl. humanistischen Gymnasiums Kempten fiir das Schuljahr 1912/13). Kempten im Allgau, 1913. (2) Neve Textstudien zum Schlussteil der aristotelischen Biologie. (Ibid., 1913/14.) Kempten im Allgau, 1914. These are the source of the readings recorded throughout the text where they differ from Bekker's apparatus.
  30. Examples are: 718 a 36, Bekker's app. aurais Z, actually avrats SZ ; 719 a 31, Bekker's app. evros, to 8' e'/crds Y, but actually PZ. Bitterauf had access to Bekker's own copj'^ of the Basel Aristotle (1550), and shows that some of Bekker's errors are due to his having used one set of symbols for the MSS. in his collation and another set in his apparatus.
  31. It should be remembered that Bitterauf's pamphlets are merely " foretastes " of his projected edition, and therefore the list of passages dealt with by him cannot be treated as exhaustive.
  32. Rhein. Mus. XL (1885), 563 flF.
  33. Aristot. Studien (1866), IV. 363, 378, 413.
  34. J. of Philology, XXXIV (1918), 254.
  35. Emendationes Aristoteleae, in Neue Jahrbiichfir f. Philol. u. Padagog. CXIX (1879), 111,
  36. Phil, der Gr. II. 2 569-570
  37. Die Fragmente der Vorsokratiker (5th edn., ed. Kranz, 1934-1937).
  38. Philologus, LIII (1894), 39-44.
  39. Guilelmi Moerbekensis translatio commentation is Aristotelicae De generatione animalium. Edidit Leonardus Dittmeyer. Programm des K. humanistischen Gymnasiums Dillingen a. D. fiir das Schuljahr 1914/15.
  40. See also P. A. (Loeb ed.), p. 47.
  41. Bitterauf quotes Scot only once, and that quotation is taken from Bussemaker.
  42. Kleinere Aristotelesfragen, in Eranos, IX (1909), 92 fF. ; see also Zmn so-genannten 10. Buck der Tiergeschichte, Upsala, 1911.
  43. e.g., D. W. Thompson, C.R. LII (1938), 15 " the dubious aid of an Arabic version " ; see also ibid., p. 89.
  44. The text of this edition is the pre-Bekker vuJgata, founded on Sylburg and Casaubon.
  45. The publication of a Spanish translation of the complete works of Aristotle was begun in 1931, but I have been unable to discover whether G.A. has yet appeared in it.
  46. Saint-Hilaire argues (I. cclix ff.) that Book V of G.A. does not belong with the rest of the treatise, but goes rather with P. A. The same suggestion, unknown to him, had been made by Weise (p. xxix) in 1843. Saint-Hilaire thinks that its inclusion with G.A. dates from the time of Andronicus of Rhodes, head of the Peripatetic School at Rome, who edited Aristotle's works from the mss. belonging to Apellicon's library brought to Rome by Sulla in 84 b.c.
  47. For other works on the early translations, see my edition of P. A. (Loeb Library).


It is a great pleasure to acknowledge here the help which I have received from many friends in many ways, and above all to thank them for their continuous interest and encouragement. First I thank Dr. W. H. D. Rouse, my old teacher and present colleague, to whom I owe, among many other things, the opportunity of undertaking this translation. The whole of the translation has been read through by my colleagues Mr. H. Rackham and Dr. F. H. A. Marshall, F.R.S., and also bv Dr. Sydney Smith ; for valuable help with some difficult passages in the Greek I am indebted to Professor R. Hackforth, and to Mr. Hugh Tredennick, who has also read part of the translation ; for much assistance in biological matters I am indebted to Dr. Marshall, to Dr. Joseph Needham, F.R.S., to Dr. Smith, and to Miss M. E. Brown. Professor A. S, Pease of Harvard University has placed me under a great obligation by most courteously securing for me microfilms of Bitterauf 's two pamphlets and of Dittmeyer's edition of Moerbeke's translation, none of which I could find in this country. It is a special pleasure to acknowledge this help from America. I am indebted to the staff of Cambridge University Library for excellent arrangements made for me to read the microfilms and also the Scot manuscripts. Dr. P. J. Durrant suggested to me that the mention of oil in connexion with lead-ore (see Bk. II. 735 b 17) might indicate an early process of flotation. Finally but not least I should like to express my appreciation of the kindness of Mr. R. Elmhirst, Director of the Marine Biological Station at Millport, Great Cumbrae, who gave me a room in which to work at my translation during a visit to Millport in the summer of 1938 and also included me in an expedition to Loch Goil for collecting marine animals closely alUed to those often mentioned by Aristotle.

A. L. P.

Easter Eve, 1942


The " Causes "

The four (1) Aristotle begins and ends the G.A. with a paragraph Causes. about Causes[1]; and indeed Causes are at the foundation of all his thought, especially of his theories about animal reproduction and development.

To know, says Aristotle, is to know by means of Causes (see Anal. Post. 94 a 20). A thing is explained when you know its Causes. And a Cause is that which is responsible, in any of four modes, for a thing's existence. The four Causes are :

(1) The Final Cause, the End or Object towards which a formative process advances, and for the sake of which it advances - the logos,(See § 10 below.) the rational purpose. • (2) The Motive (or Efficient) Cause, the agent which is responsible for having set the process going ; it is that by which the thing is made.

(3) The Formal Cause, or Form, which is responsible for the character of the course which the process follows (this also is described as the logos (See § 10 below.) as, expressing ichat the thing is, or is to be).

(4) The Material Cause, or Matter, out of which the thing is made.

(2) As an illustration of the theory of Causes the following will serve. Suppose the thing to be explained is a dog. The chronological order of the Causes is different from their logical order.

(1) The Motive Cause : the male parent which supplied the " movement " that set the process of development going.

(2) The Material Cause : the menstrual fluid and the nourishment supplied by the female parent and other nourishment taken after birth.

(3) The Formal Cause. The embryo and the puppy as it grew into a dog followed a process of development which had the special character proper to dogs.

(4) The Final Cause : the end towards which the process was directed, the perfect and full-grown dog. A similar set of examples could be constructed to suit the case of artificial objects, though some adjustments would have to be made. In both cases the Formal Cause comes from the same source as the Motive Cause, but with a difference : in the case of natural objects, the parent already possesses the Form fully realized in himself ; in the case of artificial objects, the craftsman possesses the Form " in his Soul." Both the parent and the craftsman normally employ " instruments " to deal with the "material" ; these are not mentioned in the table given above, but will be dealt with in Appendix B §§ 9 ff.

(3) Very often the Final and Motive Causes tend naturally , to coalesce with the Formal Cause, in opposition to the Material Cause; and this opposition is found in G.A. {e.g.. Book II, init.), where Aristotle regards the male (which possesses the Form and which supplies the " movement " and therefore acts as a Motive Cause) as superior and more " divine " than the female (which supplies the raw material for the embryo, i.e., supplies the Material Cause). At the same time, we shall find (l^elow, §§ 6, 7) thai the Motive and Material Causes are often together contrasted with the Final Cause, just as Necessity is contrasted with the Good.

(4) In modern parlance the term Cause has become generally limited to Motive (Efficient) Causes, as is shown by the common phrase " cause and effect " : and hence when Aristotle is concerned especially with the operation of Motive Causes (as e.g. at 734 b 9 ff.) his words have a more modern and familiar ring than when he is speaking of Final Causes.

(5) For Aristotle himself, however, it is the Final Cause, the " TeleoEnd, which is of paramount importance and which 'ogy-" dominates every process. This is abundantly clear in the P. A., where Aristotle endeavours throughout to provide a Final Cause which will explain the existence and structure of the various parts : and it is no less clear in the G.A., where the whole process of development of the embryo from start to finish Is subservient to the Final Cause : the course of the process is determined by the nature of the product which is to result from it, not the other way round : things yiyveTai. as they do because they are what they are." We are therefore justified in describing Aristotle's outlook as " teleological " ; but we must not read too much into this description. " Nature does nothing without a purpose " ; but if we ask what that purpose is, we may find that the answer is not quite what we had expected, that the purpose is not so grand as we had hoped. Aristotle seems to be satisfied when the reXos has been realized in each individual's full development ; and this is because for him Form is not normally independent of Matter (as it is for Plato) ; Form must be embodied in matter, that is, in individuals. Each complete and perfect embodiment and realization of Form in Matter is therefore for him the crowning achievement of the efforts of the four Causes - it is the End towards which they were directed. We might, then, describe this " teleology " in Bergson's phrase as a doctrine of " internal finality " : each individual is " complete " in itself.* Aristotle does, however, maintain that the " most natural " thing for an animal to do is to produce another one like itself, and hence the species is implicated in so far as it is the individual's business to perpetuate it (see App. A §§ 15 ff.). We must also remember that the continuity of yeVeaiy, one department of which is the continuous succession of generations of animals, is, for Aristotle, " necessary " (App. A § 14) ; and it is also part of the general purpose of " God," who always aims at " the better," and who, because he was unable to fill the whole universe from circumference to centre with eternal " being," filled up the central region of it with the next best available, viz., continuous yevems. " In another connexion, too, in the Ethics, we find that Aristotle looks further than the individual, at any rate so far as man is concerned, for there he tells us that man cannot attain his reAoj in the fullest sense - the " good life "- except in association (to avC'fjv) with other men

» Cf. quotation from Dante, Paradiso xx. 78, on p. 1, " Cf. § 16.

« For further details see App. A § 12.

in a (insert greek here). But this seems to be due exclusively to the fact that man possesses Reason : and so far as other animals are concerned, Aristotle does not appear to have envisaged any such widening of the (insert greek here)." From yet another point of view, however, when discuss- (e) subing the subject of property- and household management ordination at the beginning of the Politics {1256 b 15), Aristotle of animals says that just as Nature provides sustenance for animals from the verj' beginning of their existence in the larva, in the egg, or in the uterus, so we mu^t hold that after birth as well Xature provides plants for the sake of animals, and also that she provides animals other than man for the sake of men, for food and service. And if we are right in holding that Nature makes nothing without a purpose (dTtAeV) or pointlessly, we must of necessity say that " Nature has made all the animals for the sake of men." (6) As Aristotle says at the beginning of G.A. I, the two Grouping of Causes with which he is chiefly concerned in this treatise the Causes. are (1) the Motive (or Efficient) Cause, with which he had not dealt in P. A., and (2) the Material Cause. In zoology, of course, the Material Cause is represented by the " parts " of the body of an animal, and all of these except the generative " parts " * he had dealt with in P. A. ; hence in G.A. the Material Cause is represented chiefly by the parts concerned in generation - those, in fact, through which and upon which the Motive Cause operates. At the beginning of Books II and V and at the end of Book V we have further discussions about Causes, and here we find these two Causes identified with " that which is of necessity " (e^ dvdyiajs) ; while Necessity on the other side and contrasted with them is the Final versus the Cause (the Cause " for the sake of which "), which is Better, equated with to /SeAriov or rdyadov {rf. Met. A 983 a 33, etc.). Indeed, this contrast of Necessity- and the Better is continually confronting us throughout the G.^1. For instance (717 a 15 fl^.), whatever Nature does or makes is done or made either 8ta to dvayKmov or Sta TO PeXriov ; one or other of these will account for every phenomenon in the realm of Nature. The whole of Book V is devoted to those features - " conditions " {iTddr]) as Aristotle calls them - in animals which are in no way due to a Yinal Cause but are due purely to Necessity, i.e., to Material and Motive Causes. Necessity : (7) We must, however, distinguish two sorts of Necessity (the second of which will be the one just described) : (i) "con- (1) Thefirstisthat which elsewhere (f.(7.,P.y/. 642 a 7 ff., ditional •• ; a 32 flf. ; cf. 639 b 25 if., P/njs. 199 b 33 ff.)

  • Perhaps Aristotle would have been willing to include Bees, which possess some " di\-ine " ingredient (see 761 a 5).

  • It should be remembered that " parts " includes semen, milk, etc See §§ 18 ff.

Aristotle describes as "conditional" (e^ vnoddaews) Necessity ; that is to say, assuming that some end or purpose is to be achieved, certain means are necessary in order to achieve it. In other words, this is the sort of Necessity which is implied by the Final Cause being what it is. Thus, if a piece of wood is to be split, an axe or some such instrument is necessary, and the axe must, owing to the nature of the circumstances, be hard and sharp, hence of necessity bronze or iron must be used to make it. The same sort of Necessity is obviously involved in the construction by Nature of the living body and its various parts : certain materials must of necessity be used and certain processes gone through if this or that living body is to be produced." (ii) "ab- (2) The other sort of Necessity is that which Aristotle solute," (Phys. 199 b 33 et al. ) calls " simple " or " absolute " Necessity (airXcos). This applies in cases (a) where the presence of a material object or set of objects {i.e., a Material Cause), and the fact that their nature is what it is, entails as a necessary consequence a certain result or set of results ; (6) where the nature of the " movement " set up by an activating agent (a Motive Cause) similarly entails certain results. This " simple " or " absolute " Necessity may therefore be regarded as the sort of Necessity involved in the Material and Motive Causes - as a reassertion of themselves by these Causes against the Final Cause {G.A. 778 b 1) and against Nature as she advances towards her achievement of it. " In the field of natural objects. Necessity is what we call matter and the Kivrjaeis of matter " {Phys. 2(y2 a 3-2)."

  • Thus even this Necessity can be said to be located " in the matter " (Phvs. 200 a 15).

(8) Aristotle, however, is continually drawing our attention nsed by to the adroitness of Nature in emplojing the results of Mature to this latter .sort of Necessity in order to serse her purpose, pu^Mse ; in order to achieve her end. For example (738 a 33 ff.), the production of " residue " by females is e'^ avayicqs, simply because the female is not hot enough to etfect complete concoction ; but Nature makes use of this residue to provide the material out of which the embryo is to be formed. Other instances of things which, though occurring i^ dvay/o;?, are nevertheless employed bv Nature eveKo. tlvos, will be found at, e.g., 739 b 28, 743 a 36 ff.. 755 a 22, 776 a 15 ff., b 33. See also P.A. 642 a 31, 663 b 13, b 20 ff. On the other hand. Nature cannot always manage to do this, and what results then is a useless residue (e.g., excrements), or a " coUiquescence " (P.A. 677 a 1-2 ff.). These by-products, however, may still be regarded as " natural," because they are of general occurrence (that is one definition of what is " natural"; see G.A. 727 b 29, 770 b 10 ff., 777 a 20 ff., P.A. 663 b 28). When, however. Nature is more seriously thwarted by the indeterminateness or the unevenness of matter (G.A. 778 a 7 ; «•/. App. A § 11), we find unnatural results occurring, such as monstrosities and deformities (see G.A. IV. 766 a 18 et passim).' (9) The "simple" or "absolute" Necessity described in(iii)"abthe preceding paragraphs refers only to the limited field 8?l«te " of some particular yiyvo/ievov, l.e.l to the process by the'^u^n/verse means of which some particular natural object is pro- as a whole. duced and to the Causes therein concerned. But there is a wider and more universal meaning of " simple " or " absolute " Necessity (which we may, if we like, consider as being an extension by Aristotle of the narrower meaning of Necessity as applied to the yeVcaij of individual things, though it is really on a different plane) - a Necessity which embraces the whole field of yeveais in the universe at large, i.e., the whole process of the seasonal and cyclic transformations of the " elements," and the whole process of the cyclical generation of animals and plants (see App. A §§ 12 ff.) ; and which even further still {ibid. ; and see P. A. 639 b 24) includes those things which do not pass through a process of formation (ydvecns) at all, but persist eternal and immutable. In this context Aristotle lays down {G. 4' G337 b 35) that i^ dvdyKTjs and del coincide ; thus " eternity " - whether it be individual eternity, as of the stars, or specific eternity, as of plants and animals - and Necessity are mutuallj' interconnected (see App. A § 14) ; thus, that which always is or always yiyveraL, is, or yiyverat., of necessity ; that which is, or yCyverai, of necessity, is, or yiyverat, always. This meaning of " absolute " Necessity, however, does not enter directly into the G.A., though it is once touched upon in passing (at 770 b 12 ; cf. 742 b 26 if.), and it is incidentally implied to some extent in the passages of Books II and IV referred to and supplemented in the Appendix, A and B.«  Aoyos

  • The verb avfi^iveLv (sometimes in the phrase <rvMi3aiVti e^ at-oiyicrff ) is frequently used with reference to the results of this sort of Necessity, as being facts which merely " occur " and are not designed to forward any purpose.
  • " A " colliquescence " may be an unnatural by-product ; see G.A. 724 b 26-29 and § 67 below.
  • For further notes on " Nature," see §§ 12 fT.

(10) Frequently in the translation, rather than represent Xoyos by an inadequate or misleading word, I have transliterated it by logos. This serves the useful purpose of reminding the reader that we have here a term of wide and varied application, with which a number of correlated conceptions are associated, one or other of which may be uppermost in a particular case. The fundamental idea of Xoyos, as its connexion with Xeyeiv shows, is that of something spoken or uttered, more especially a rational utterance or rational explanation, expressing a thing's nature and the plan of it ; hence Xoyos can denote the defining formula, the definition of a thing's essence, of its essential being (as often in the phrase Xoyos rrjs ovalas), expressing the structure or character of the object to be defined. See also § 1 above.

  • Other modes of Necessity not relevant to G.A. are here omitted. * The less technical meanings are translated in the normal way.

11) For want of a better term, and in order to preserve the line of Aristotle's thought, I have usually translated ap^TJ by "principle," or "first principle." There is, -however, really but little difficulty about this term, for the context will usually indicate what its connotation is. A few examples of its use may be given. (1) Often, as at 715 a 6, it is a principle or source of " movement " {dpxf) TTjs Kimjaews). Hence, obviously, (2) the Motive Cause may be described as an dpxn, and so too may the other Causes (^.^r., 716 a 5 IF., 778 a 7), including Matter: and for the same reasons the sexes also are dpxai ; so is semen. (3) An dpxrj is something which though small in itself is of great importance and influence as being the source or starting-point upon which other things depend, and which causes great changes (Kivrjaeis) in them (<•/. 716 b 3, 763 b 23 tf., 766 a 14 fF.). An dpxT] may, of course, be of greater or less fundamental importance : and the ultimate dpxrj of an animal is its heart {e.g., 766 a 35), though there are also dpxai that are external to the animal, e.g., the sun and moon (777 b 24).

13) Tlijpwfia, dva-TTTjpia, and cognate words occur several " Deformatimes in G.A., and for convenience I have translated tion." them " deformation " or " deformitj-." Other possible renderings, none of which fully brings out the meaning of the Greek word, are given in the riote on 737 a -25. The underlying notion is that (f>vai.s has not succeeded in achieving her proper re'Ao? ; and this close connexion of TTqpcjfia with a falling short of natural completeness is clearly brought out by the reasons given at 724 b 33 why semen cannot be a irqpcufjLa, viz., because it is found in all individuals (for that which is " general " is " natural," see § 8), and because 17 <f>vai.s yiyv^Tox out of semen.

13) Perhaps the most striking instance of Aristotle's applica- The female tion of this idea is his statement (775 a 15) that female- » "<!?ness (^TjAirnj?) is " as it were a natural dvaTnjpla." Here f°°»'*y" we have two conceptions of Nature asserting themselves in Aristotle's mind u (1) that the male represents the full development of which Nature is capable ; it is hotter than the femstle, and more " able " t<5 eflFect concoction, etc. ; but at the same time (2) the female is so universal and regular an occurrence that it cannot be dismissed out of hand as " unnatural " ; besides, the female is essential for generation, which is a typically " natural " process (see § 5). Nature (14) This opposition of " Nature " to " Nature " is, however, versus not unique, for it is found elsewhere in Aristotle ; e.g., ature. ^^ G.A. 770 b 20 he can say that to napa (f>vaiv is in a way Kara (f>vaiv, viz., when rj Kara to elSos (j>vais has not mastered -q Kara ttjv vXrjv <f)vais ; and at P. A. 663 b 22 he speaks of r/ /cara top Xoyov (f>vaii making use of the products of rj dvayKaia (fyvais in order to serve a purpose {cf. also P. A. 641 a 26, 642 a 17 ; at Phys. 199 a 31 Aristotle distinguishes <f>vai,s ois vXr] and ^uaiy ws yMpifyq, the latter being a reAo? and 17 atVia 17 ov eveKa. Cf. 729 a 34, n.). Nature: (15) It is impossible and unnecessary to provide here a full as purpose ; account of what Aristotle intended by the term <f>vais, since a proper understanding of it can best be obtained by reading Aristotle's works themselves, and for this G.A. is one of the most useful, because it is pervaded bj' references to <f>vai5. A few remarks may however be made here about (j>vat.s in its highest manifestation, compsrable (16) By Aristotle, (f)vais and the products of ^vols are conto an stantlj' compared with rixvr] and the products of t€xvt] : " â– ^voLs works to produce a finished product, a reAoj, just as the artist or craftsman does " ; and (f>vais, again like the artist, uses " instruments," charged with a specific " movement," in order to bring these products to fulfilNature as ment. And the most typical of the products of <f)vais Soul. are, of course, living creatures ; indeed, Aristotle can speak of the <f>vais of each living thing as being identical with nutritive Soul (741 a 1, where see note, and cf. P. A. 641 b 9), the Soul which generates and fashions it and promotes its growth ; and again {De caelo 301 b 17), (l>vais is to be regarded as a principle of movement in the

  • is also compared (744 b 16) to a careful housekeeper, who throws away nothing that is useful ; or to a cook (743 a 31 ; cf. 767 a 17 ff.), tempering the heat of her stove so that the food she is preparing may be done to a turn. See also Su/a^erpia, § 39.

thing itself. An artist, then, at work - jes, but in each several thing ; and it is doubtful whether Aristotle had, or intended to have, any idea of Nature over and above, outside, the individual things "â– which he described as her " works." In fact, he goes so far as to say {P. A. 641 b 11) that no abstraction can be the object of study for Natural science, because Nature makes all that she makes to serve some purpose (evc/ca tov). Nature aims always at producing a reXos in the sense of a completely formed individual, and that is the Final Cause in each case, for that is what has the best claim to be called a " being " (ovoia).^ There is, says Aristotle, more beauty and purpose (to ov Ice/ca aal to koXov) to be found in the works of Nature than in those of art (P. A. 639 b ^0).

(17) Nevertheless, we must remember that Nature is not, in Xature as Aristotle's view, a term to be exclusively reserved for the matter. Final Cause, with which are associated the Formal and often the Motive Causes ; it may be applied also, as we saw just now {i 14), to the Material Cause ; and in this connexion we may recall that, for Aristotle, Matter and Form themselves pervade all the strata of existence, for even the simplest sort of Matter is to some extent " informed," and Matter in its highest phase is identical ' with Form (see 7-29 a 34, n.).

^lopiov, p-epos, "part " (18) The term " part," which occurs in the title of the treatise Meaning. De partibus animal ium, nepl ^uicdv (jLopiiov (or, as Aristotle himself calls it at G.A. 782 a -21, " the treatise Of the Causes of the Parts of Animals "), includes considerably more than is normaliy included by the English " part of the body." For instance, we should not normally call blood a " part," but Aristotle applies the term fiopiov to all the constituent substances of the body as well as to the limbs and organs. For him, blood is one of the ^dwv fjLopia (see P.A. 648 a 2 : and note on G:A. 720 b 31). Since, however, all the " parts " are either " uniform " or " non-uniform," a detailed description of them will be more appropriate in the following paragraphs.

" See however § 5 above. " See App. A § 18.

To, ofioiofxeprj fiopia, the "uniform parts" To, dvofJiOLOfieprj [lopia, the "non-uniform parts" (19) At G.A. 724 b 23 if., Aristotle classifies the substances found in the body into five divisions, one of which is Two sorts " natural parts," " and this division he subdivides into of "parts." "uniform parts" and "non-uniform parts." As examples of " uniform parts " he cites {P. A, 647 b 10 ff.) blood, serum, lard, suet, marrow, semen, bile, milk, flesh * (these are soft and " fluid " " ones) ; also bone, fish-spine, sinew, blood-vessel (these are hard and " solid " ones). And although in some cases the same name is applied to the substance out of which the whole is made and to the whole that is made out of it,"* this is not true in all cases. Examples of " non-uniform " parts are {P. A. 640 b 20) face, hand, foot. Relation (20) The relation of the " uniform " to the " non-uniform " between parts Aristotle describes as follows {P. A. 647 b 22 fF.) : them. ^^^ some of the vmiform parts are the material out of which the non-uniform are made (i.e., each instrumental part is made out of bones, sinews, flesh, etc.) ; (b) some, viz., " fluid " ones, serve as nourishment for those in class (a), since all growth is derived from fluid matter ; (c) some are " residues " ' from those in class (6), e.g., faeces, urine.

  • This must not be taken to imply the existence of MWw«<Mrai" parts."
  • Some of these are also " residues " ; see below, § 65.
  • For the meaning of " fluid " and " solid," see below, § 38.
  • e.g., we speak of " bone " and " a bone " ; Aristotle's own example Is *' blood-vessel."
  • See § 65.

Thus it is not possible to equate this division into uniform and non-imiform parts with the more modern division into tissues and organs ; for instance, blood, though a uniform part, is not a tissue. The term " organs," on the other hand, corresponds closely with Aristotle's own description of the non-uniform parts {P. A. 647 b 23) as rd dpyavi/cd (idpr), " the instrumental parts." (21) The fundamental difference between the two sorts of " parts " is that each of the uniform parts has its own definite character as a substance (in the modern sense), while each of the non-uniform parts has its own definite character as a conformation or organ. The heart is the only " part " which belongs to both classes {P. A. 647 a 25 ff.) : it is made out of one uniform part only, but at the same time it has essentially a definite configuration or shape, and thus it is a non-uniform part. (â– ??) The four stages or " degrees of composition," so far as The stages biology is concerned, are thus enumerated by Aristotle o^ com (G.A. 715 a 10 ff. ; <â– /. P.A. 646 a 13 ff.) : ' position.

(1) The four " Elements," Fire, Air, Water, Earth " ;

(2) the uniform parts ;

(3) the non-uniform parts ;

(4) the animal organism as a whole.

We thus begin from the simplest sorts of matter (Aristotle calls the four Elements " simple bodies ") and proceed upwards by stages until the most organized or most " informed " sort of matter is reached : each stage is the " material " for the stage next above it {G.A. 715 a 9 ff.).

Ai'i'ay^iS (23) This term has a number of different, though related, meanings, and it is not always easy to determine precisely which one Aristotle has uppermost in mind. Unlike some other terms, therefore, this one cannot always be represented hx the same term in English, and sometimes it is best left untranslated.

(24) (A) To begin with, we will examine the pre- Aristotelian Dynameis meaning of bwafus, as found for instance in the Hippo- ^^ elementcratic corpus and in Plato's Thnaeus. Awa^s was the oPniaUer old technical term for the simplest sorts of matter, i.e., for what came later to be called cnoixela (" elements "). Auva/us was however applied exclusively to substances of a particular class, viz., to vypov, to ^pov, to QepfjAv, to ijtVXpOV, TO TTlKpOV, TO yXvKV, TO SpifJiV, etC, CtC. lu thC Hippocratic treatise irepl dpxcurjs IrjTpiicqs (The Ancient and Genuine Art of Medicine) these substances are regarded as being the constituents both of the body and " In the P.A. passage Aristotle says it might be better to substitute for these " the iuvo/icij," or rather four of them ; see below, § 24. Fire, Air, Water, Earth are of course the constituents of non-li^ing things as well ; see App. A § 2.


ARISTOTLE of its foods. The Swa/A€ij are referred to by Aristotle at the beginning of P.A. II (see § 23, note), where he speaks Harth, Air, of " the ' elements ' as they are called, viz.. Earth, Air, ^^resoivaWe ^^'ater, Fire, or perhaps it 'is better to say the Swa/tei?- into "ot all the Swdfieis, of course, but these four, vypov, dyiMineis. ^jpov, 0€pfj,6v, i^upf/wv." The explanation of this is that although Aristotle held that in a sense Earth, Air, Water, and Fire were " elements," i.e., that they were the simplest states of matter actually found in the world as we know it, yet theoretically each of them could be resolved into a pair of bwdfieis : thus Fire is Oepixov and ^â– qpov. Air Oepfiov and vypov. Water tfwxpov and vypov. Earth i^vxpov and $r]pov (G. 4- C. 330 a 30 if.), each of them l)eing characterized by one constituent ])ar excellence. Fire by depftov. Air by vypov, \A'ater by ijwxpov. Earth by ir/pov. According to Aristotle, all other physical " differences " are consequent upon these four fundamental ones. Origin of (25) The meaning implied in this use of Swafus seems to have this usage. been " substance of a specific character '" (perhaps the adjective " strong " should be prefixed : this would of course be very appropriate to Swifieis such as -o Spi/xv, TO iTiKpov, etc.). But originally, no doubt, the term was an item in the Pythagorean political metaphor terminology, as would appear for instance from the theory held by Alcmeon " that bodily health was maintained by the laovofiia tu>v Swdfxecov, and that the " monarchy " of any one of them produced disease. It is important to notice that there is no notion here of the substance having power in the sense of power to produce a specific effect * upon a body, though this was a meaning " See Aetius v. 30. 1 (Dials, Doxographi Graeci 442).

>> e.g., causing stomach-ache. In Plato's Timaeus we find this extended meaning of Jura/m? {i.e., power to produce a specific effect) side by side with the old meaning of specific substance ; and it is frequent* in ir. 6iaiVj)s. Clearly, this marlis a change over from the medical theory originally associated with the political metaphor terminology ; and we find that, as Svfofii? takes on the meaning of " power to produce a specific effect," the term " humour " comes in to denote the specific substances to which iivvatm was originally appUed. Thus Diodes {apud Galen vi. 455) can argue against doctors who hold that aU things which possess similar " humours " also possess the same iui-ofici? (powers of producing specific effects on the body), e.g., are laxative, diuretic, etc. There is no space to say more here on this development, wliich I dealt with fully in my thesis Pseudo- Hippocrates PhUosophm (1928). Studies 1 '

GENERATION OF ANIMALS which developed later. A hwafus is rather a substance which is a power, which can assert itself, and by the simple act of asserting itself, by being too strong, stronger than the others, can cause trouble. The remedy in such a case is to deprive it of some of its strength, until it again takes its proper place among its peers, or, in the language of medicine, to " concoct " it or otherwise bring it into a harmless condition by " blending " " it with the other substances.

(26) (B) As each of the substances known as Swdfieis had its Dynunieis as own specific and peculiar character, sharply marked off sutetances from the others, it was easy for the meaning " peculiar tive char^' and distinctive character " to become closely associated acter. with the term Svva^s, quite apart from any reference to these particular substances. In fact, it almost comes to mean any " substance of a distinctive qualitj- " ; and in this sense it is found in G'..i., for instance at 720 b 32 (oAAtj Tis SuVa/xts) and 736 a 21 (Aphrodite was called after " this hwafjus," sc. d<f>p6s, foam). From this it is an easy step to " distinctive physical quality," or simply " distinctive character " (as, e.g., at 731 b 19, where it is Joined with Xoyos rijs ovalas ; at 751 a 33, where it refers to the distinctive character of the yolk and white of an egg respectively * ; and cf. 733 b 15 l^et bvvafuv (hov - it has the distinctive character of an egg, it is equivalent to an egg ; and 780 b 8, 784 b 15) : or " characteristic " (applied to the sexes at 756 a 1, 763 b 23 ; cf. 760 a 19).

(27) In the sense of " (substance of) distinctive character " it can be used practically as an alternative to <f>vai.s, or in conjunction with ^u'ai? (as indeed it often is in Hippocrates and Plato), and this seems to be the use of it in P. A. 655 b 12 i^ avayKTis 8e raura navra y€U)8T] Kal arepeav !;(« ttjv (f>vaiv ottXov yap avrt] 8vvafjLis {cf. P..1. 651 b 21).

(28) (C) From this usage it is not far to the idiomatic, pleo- Idiomatic nastic usage, e.g., 17 twv evripwv Su'va/iij (almost=Ta usage. evrepa P. A. 678 a 13) ; ij tuiv Trrepajv ( = Ta Trrepd, 682 b 15); and this is -paralleled by the similar usage ou some of the uses of Sxivani^ have been made by J. Souilhe, £tude sur le terme Suvo/iis drins les dialogues de Platon, Paris, 1910, and A. Keus, Vber philosophisehe Begriffe u. Theorien in den hippokrati^chen Schriften, Coin, 1914, pp. 46 flF. " See § 40. <^iiiTiv is used in a similar context at 753 a 35.

ARISTOTLE of </>UCTi?, e.g., Tj Tcor oarpaKobepficDV <f>VGis ((r.A. 761 b 24), ri Tov alboiov (t>vais (717 b 18 ; cf. also 755 a 20), 17 twv TTTfpcbv <j)vais (749 b 7, a striking instance, because <l>vais is used in an entirely different sense, " Nature," in the very next line) ; and even avaraais is sometimes used in a similarly weakened sense, e.g., 1; tcov opxecov avaraais {G.A. 717 a 15), ij tmv Karafn/jviajv avaraais {G.A. 727 b 33) : and avoTaais appears in two manuscripts as a variant for <f)vais at G.A. 717 b 20. Dunamis in (29) (D) In the passages dealing with the role of the male generation. parent in generation we find phrases such as " the %vva^i,i,s in the semen," " the Swa^iis in the male " {e.g., 726 b 19," 727 b 14, 729 b 27, 730 a 3, a 14, 736 a 27, etc.). The meaning of 8wa/xiy here would appear to be fundamentallj' the same as that dealt with in § 26 above, i.e., bvvafxis here is the physical substance by means of which impregnation is effected ; and the distinctive physical characteristic with which we find this SvvaftLs closely associated by Aristotle is " vital heat " or " Soulheat." * The most distinctive characteristic, however, of this substance is that it is charged with a specific AsBociated " movement," capable of constituting and developing ,, with an embryo out of the matter supplied by the female ; j^°^^n and hence we also find a close association of Bwa/iis with Kivrjais." This is the most important extension of bvvaptis in its ancient sense made by Aristotle, for it links up the old sense of the term with the typically and peculiarly Aristotelian sense of Swa/xts=" potentiality " (see §§ 34 ff. below). (30) (E) Under the same category comes the use of Sura/nis and dSwafua as applied to male and female respectively {G.A. 765 b 9 ff., 766 a 32 ff.), for these are explained by Aristotle as the ability and inability respectively to effect " concoction " of the ultimate nourishment (blood) into semen, and this is directly dependent upon the possession of sufficient " natural heat." " An interesting example, because dvvaixei. ( = potetUially) occiu« in the previous line.

  • Not to be confused with the ordinary ivvatm " etptLov " ; see App. B §§ 13, 18.

<^ References for Svva^jLK; associated with "vital heat" and kiitjo-cs, e.g., 726 b 19 ff., 729 b 6 ff., 738 b 12, 739 b 24, 740 b 30 ff., 767 b 17 ff. (cf. 755 a 20 " the </)uo-is of the Soul-heat "). See also xiVijcris, § 50.


GENERATION OF ANIMALS (31) (F) Under the same category too must be placed the use of the term Swa/xts in the remarkable discussion on heredity in Book IV. This is admittedly a particularized use of the term," and Aristotle carefully explains its meaning when he first introduces it (767 b 2S if., q.v.). But here too it is applied to special and distinctive characteristics, be it those of genus, species, or individual, and therefore this use of it stands in the same line of succession as the meaning already described in §§ 24 fF. As for the way in which Aristotle conceived these Swa/i«? to operate, it is clear that, as they were present both in the semen and in the menstrual fluid (see lor. cit.) and gave rise to /fivTywet? (767 b 36), they must have been closely associated with Soul and inherent in its instrument pneuma.

(32) It may be noted here that the physical substance con- Pneuma. cerned throughout the theory of generation is pneuma (a substance " analogous to aitker," the " fifth element," the " element of the stars "), with which Soul is " associated " ; and it is this pneuma which Soul charges with a specific " movement " and uses as its " instrument " in generation just as it does in locomotion, and as an artist uses his instruments, to which he imparts " movement," in order to create his works of art. (For fuller details about pneuma, see App. B, and cf. % 45.) (33) Thus Swofu^, even at its most glorified, still retains the Continnity marks of its descent from the historic Swa/xty of the '"l meaning early medicine, for, although Soul-heat is something ° yncimxs. different from the old depfiov and superior to it, nevertheless it is still depftov. And there is another respect in which its descent is still to be seen, though this time it may be fortuitous and perhaps no more than a verbal coincidence. This physical substance is the vehicle for the activity of Form (eiSos) ; and in the Hippocratic treatise tt. apxairjs iTp-pucrj^ each of the innumerable physical substances known as 8wa/ici? had also been called an eJSo?.

(34) (G) We now come to the last and most tv'pically Aris- Dyna»ii» as totelian of the meanings of bwafus : and although it is ".P"*^,"^' « And therefore I have felt justified in translating it " faculty " in this sense, to avoid repeated reciurence of the Greek word transliterated. It may perhaps l)e simply an extension of the meaning dealt with in the last section but one.



Association (35) of dynamis with "movement."

"Potenti- (36) ally" and ' in actu.'ility."

Erroneous (37) translations of dynamis.


usually considered independently of the ones we have already described, it is clear from Aristotle's own words that he did not so regard it himself, for he associates it very closely with Kivrjms. In Met. A 1019 a 15 ff. and 1046 a 10 f., he defines the primary and fundamental sense of Swa/xis in this connexion in the following words : Swa/xiy is apx^] Kivrjaecbs ij /ierajSoA^j eV irepo) rj â– ^ erepov : Svvafiis is a principle (or source) of Kivrjois or of change - a principle either (a) subsisting in some other thing than that which is to be affected by the Kivrjais or change, or (6) subsisting in the thing itself qua other than changeable in that respect. An example of (a) is building ; an example of (h) is the science of medicine in the case of a person who is being healed but not qva being healed (a man doctoring himself). That is the fundamental sense of this 8vVa/xis ; but Aristotle goes on at once to mention the complementary sense of it, which in fact is the sense in which he commonly uses it, viz., the Swa/Mis of being acted upon {-Tradetv), which he describes as the dpxrj in the thing acted upon of a passive change caused either by some other thing or by itself qita other {rj iv avru) tw Trdaxovri dpxr] (lerafioXfis TTadT]Ti.KTJs vtt' dXXov r/ â– ^ aAAo).

It is therefore clear that there is the closest possible connexion between this notion also of bvvap,is and Kivrjais : Suva/xis is in fact the capacity to set up " movement" or (more commonly) to be set in " movement " : it is a " djnamic " conception. To say that A is B Swa/xei (potentially) means that A is a Material Cause capable of being set moving with a certain Kivqais by a Motive Cause, which Klvrjms will result in A acquiring the Form of B, thus attaining the Final Cause (becoming a B itself). It is thus a conception which integrates the four Causes through the process of Kivrjais. The correlative of Swdfiei. {potentially) is evepyela (in actimlity) ; " X evepyeia " means something in which the Form X has been realized - something which already possesses the Form X, and further, in the case of animals, something which can reproduce the Form X in other matter which is so far only " Swdixei X." Of all the possible translations or mistranslations of bvvafjus, " force " is one of the most misleading ; for

GENERATION OF ANIMALS there is nothing more fundamental in Aristotle's - and in his predecessors' - idea of 8wa/ than that it is something natural ; and the associations of the term " force " run counter to this. Aristotle himself contrasts " natural " and " enforced " movement (see App. B § 22, and cf. 739 a 4, 788 b 27, Politics 1253 b 22). It is also important that any notion of a vague and indefinite urge, even (and perhaps especially) where Soul is involved, should be excluded ; for, as we haveseen, 8uva/iis is associated primarily with some material substance of a specific character or with some Kivrjais (carried in a definite substance) of a specific character. From every point of view it is best to avoid " force " altogether as a translation of Svvafus.

To vypov Kal to ^i)p6v, "Jiuid substance and solid substance " (38) These are two of the original Swdfieis (§ 24) ; and Translation, following Ogle in his translation of P. A. I use the above renderings as being more in conformity with the definitions given by Aristotle himself than " moist " and " dry " which have sometimes been used. Actually neither pair of English words quite expresses the Greek. Aristotle's definition of them (at G. 4" C. 329 h 30) is Definition, this : " vypov is that which is not bounded by any boundary of its own but can readily be bounded ; ^Tjpov is that which is readily bounded by a boundary of its own but can with difficulty be bounded " ; at the end of each definition there should of course be understood " by a boundary imposed from without." (vypov is to dopiOTov oiKeio) opat evopiarov ov, ^rjpov is to evopiarov fiev olKeiip 6p<x) hvaopiarov he.) ^i'fifi€Tpia, K/aacris (39) An idea which recurs a number of times in G.A. is that Correct proof avfifxerpia. In this treatise the majority of the refer- portion : ences " to avp.y.eTpia are concerned with the relative ^"^ ^^ .. amounts of residue contributed in generation by the two *^° * '°° ' « See list of passages in the Index.



parents, or to the heat or " movement " contributed by the male or otherwise provided (e.g., by the Sun). TiV/xnerpos KivTjais is also mentioned in connexion with the amount of fluid in the pupil of the eye (779 b 25 ; cf. 780 b 24). The meaning throughout is that the amount of substance, or of heat, must be adjusted in the correct proportion ; and this, as the context at 786 b 5 indicates, means suitably adjusted between the two extremes of too much and too little. This at once recalls to mind the famous doctrine of the " meaH " in the (h) in ethics Ethics, where goodness (or "virtue," dper^) is held to and politics; bg a mean between the two extremes of excess and deficiency ; indeed, at E.N. 1104 a 12 flF. Aristotle says that whereas the moral dperai are destroyed by excess and deficiency, they are produced and preserved by the mean, just as excessive food and drink destroy health, (c) in bodily whereas to. avmierpa produce and preserve it." Simi health. larly, at Phys. 246 b 4 he says " we posit that the dperai of Blend. the body, viz., health and fitness, lie in the Kpdms (blend) and avfinerpla of hot things and cold, either as regards each other internally, or as regards the surrounding environment ; and the same applies to the other dperai and K-a/<t'at." This reference to Kpdais and to the environment is closely parallel to the most important passage on avp-pierpia in G.A., 767 a 14 fF., where Aristotle says that the male and female need avp,fierpia as towards each other, because all things formed by Nature or by Art Adya» rtvi earw - depend upon a certain proportional relationship, or ratio. Just as in cooking, the heat must strike the due proportion, the mean, or your meat will be either overdone or underdone. So too in the mixture of male and female, ovftpLerpia is required. He then goes on to speak of the dependence of our bodily condition upon the Kpdais of the environing air (cf. 777 b 7) and of the foods we take, and especially the water. (40) This is not the place to discuss the origin of the doctrine " The importance of a-vfi/j-frpia in the growth of a State is also empliasized by comparing it with the growth of the body (Pol. 1302 b 35 ti.).

>> Cf. the phrase i^vxporepa tjjs o-u/x/xeVpou icpao-ews used of the parts around the brain (P. A. 652 b 36).

■; C/. § 16 above.


GENERATION OF ANIMALS of the mean, nor of the closely allied doctrine of Kpdms, except that it should be noted that great importance is attached in the Hippocratic treatise it. apxairj^ Irjrpiicqs to securing proper Kpdais for the ingredients of the food we take and of the constituents of our bodies (the two sets of substances being identical) ; and that in it. biai-njs the Kpdais of Fire and Water in the Soul is responsible for its health and sensitivity (c/. G.A. 744 a 30). References to the pertinent passages of the Hippocratic treatises will be found in the notes ; see also P. A. (Loeb ed.), pp. 37 f. It should also be noted that Alcmeon of Crotona (Aetius v. 30; see Dieh, JJoxographi 442) held that health was the avfifieTpos twv itoiwv Kpdais {rf. § 25). It is important to realize that some, at any rate, of Aristotle's terminology was the common property of scientific wTiters, ^vX'i], " Soul " (41) The English word Soul, as will be seen, owing to its associations is not entirely satisfactory as a rendering of ipvxT^, but it is by far the most con\-fenient one, and I have used it in preference to " life " or " vital principle " (for which Aristotle employs other terms).

(42) Animate bodies, bodies " with Soul in them " (eijjpvxa). Soul the are " concrete entities " made up of Form and Slatter, ^°™ "^ Soul being the Form and body the Matter ; indeed, ^^ySoul is the Form of the body. '{Cf. G.A. 738 b 27, n., 741 a 1.) Aristotle also describes this relationship by saying that Soul is the " realization " (oTeAe'xeta, " actuality ") of the animal body. Strictly speaking. Soul is the " first realization " of an animal body, for an animal can " have Soul in it " and yet be asleep ; its active, waking life will be its " second realization." Further, Aristotle tells us that Soul Ls the first realization of a body furnished with organs. The importance of this is clear : the body is for the sake of the Soul (because the Soul is the Final Cause as well) ; and hence {P. A. 687 a 8 ff.) Aristotle maintains that man has hands because he is the most intelligent animal, not, as some had said, the most intelligent animal because he has hands. Soul is ^' prior " to body, and the body is such as it is because that is the sort of body the Soiil


' requires in order to function. Indeed, the Soul cannot function without a body ; it cannot, we may say, exist (De anima 414 a 19).

The (43) This will be clear if we distinguish the different parts or faculties " faculties " of Soul. They can be arranged in a of Sonl. definite order, so that the possession of any one of them implies the possession of all those which precede it in the list ; and it will be seen that all except the last of them obviously require a body for their functioning.

(1) Nutritive and generative Soul," in all plants ; (2) sentient Soul, in all animals ; (3) appetitive Soul | .^ ^^^^ ^^.^^^^ (4) locomotive Soul ) (5) rational Soul, in man only. Rational (44) It is the last faculty of Soul which stands out by itself.

Soul. Aristotle feels that he cannot admit that Soul is wholly dependent upon body for its functioning ; there may, he says, be some " part " of Soul which is not the " realization " of any body, a " part " whose activities have nothing whatever to do with any physical activities {G.A. 736 b^28). This part, which is "rational Soul," comes in over and above, from without {G.A . 736 b 25 fF.), and continues to exist after the death of the body {De anima 413 a 6, b 24 ff., 430 a 22, etc.. Met. A 1070 a 26). The problems raised by this belief are, however, not fully dealt with by Aristotle even in G.A., where he has much to say about the development of Soul in the embryo ; indeed, he nowhere offers any solution of them. Soul (45) So much then for the theoretical relationship of Soul subsists in and body. What is their practical relationship ? How pnexvma. precisely does Soul function through the body ? The answer to these questions is one of the most striking parts of all Aristotle's philosophical work. Soul, says Aristotle, is not, as some have wrongly supposed. Fire or any such stuff (Swa/iiis) ; it is better to say that it " subsists in some such substance " as Fire (ev tomvtw Tivl acufiari aweardvai), viz., in " hot substance " (to depfjLov), which is the most serviceable of all substances for the activities of Soul {P. A. 652 b 8) ; and elsewhere {G.A. 736 b 30 ff. ; see App. B § 13) he is more explicit.

" See also 744 b 33, n.


GENERATION OF ANIMALS This depfiov is no ordinary depfxov, but it is pneuma, a substance " more divine " than Fire, Air, Water, or Earth, and " analogous to " the fifth element, aither, the element of the t'pper Cosmos. It is this pneuma, and the substance {<f>vai.s} in the pneuma, which is the vehicle of Soul, and it is pneuma which Soul uses as its " instrument," through which it brings about kIvtjctis, both in moving the full-grown body and in " moving " i.e., developing the embryo. Here, then, we have reached the heart of the business : pneuma is the last physical term of the series : pneuma is the immediate instrument of Soul, and it is through pneuma first of all that Soul expresses itself.

(46) It must not be supposed that this pneuma is the breath This breathed in by the animal from outside ; Aristotle is v^ is most explicit on this point, and he often describes this "connate. pneuma as " connate " (o-v^i^utov). Owing to the important place of 'Lv^i<j>vtov Iivfvp.a in Aristotle's biology, I have provided a full account of its nature and functions in Appendix B." KtV//(ris (47) KivTjffts is a term of wider range than the English " move- Meaning. , ment," though it is useful to retain " movement " as a translation in order to preserve the line of Aristotle's thought. Ki'iTjais is one department of /xcra^Aij (Change), of which there are three divisions : Two, which are changes affecting ovala : ( 1 ) yiveais, change from the non-existent to the existent ; (2) ifSopd, change from the existent to the non-existent. And one, which comprises changes affecting categories other than ovaia : (3) KivTjais, change in existing things.

(48) Ki'iTjais has three subdivisions : Varieties ot (a) as regards Quantity : Growth and diminution ; "moveit) as regards Quality : " Alteration " (dAAoicoai?) ; ment." " See also G. L. Duprat, La theorie du TrveO/no chez Aristote, Archiv f. Gesch. d. Phil. XII (1899), 305 ff., and W. \V. Jaeger. Das Pneuma im Lykeion, Hermes, XLVIII (1913), 29 ff. ; the latter also gives a history of the pnewma-doctrine. See also W. W. Jaeger, Diokles von Earystos (1938) and J. I. Beare, Greek Theories of Elementary Cognition from Alcmeon to Aristotle (1906).



"Move- (50) ment" and Form.

(c) as regards Place : Locomotion (^opa), either (i) in a circle, or (ii) in a straight line. Sometimes Aristotle includes yeWai? and <f>dopd as a fovirth subdivision of Kitn^ais, thus making KivTjais embrace every variety of change. (See also Met. A 1069 b 8 ff.) DeQnitioD. (49) The definition of Kivrfais which he gives at Phys. 201 a 1 1 ff. is this : ij tov Swafxei ovtos evreXexf'-O'i ?5 toiovtov, KLirqais ioriv : " Movement " is the realizing of that which is potentially X, qua potentially X. For example, to take the case of dAAota>ai9, Kimjais is the altering of a thing which is alterable, fpia alterable ; and so with the other modes of potentiality.

It will be seen at once that, in order to set going the Kivinaeis by which the various potentialities are to be realized. Motive Causes are required. And the thing which causes the " movement," says Aristotle {Phys. 202 a 10), will always bring with it some Form (maybe some ovala, or some quality, or some quantity), which will be a " principle " and a cause of " movement." In other words, the " movement " will be informed, determined, characterized, in such a way that it will produce a thing which has a certain ovoia, or quality, or quantity. The agent (or Motive Cause), then, will set up in the material a " movement " which will result in the material which is potentially A becoming A in actuality, that is to say, in its acquiring the same Form as that which the agent possessed. And this result is brought about, generally, by the use of an intermediary, an " instrument " (see App. B §§ 6, 15), to which the agent imparts the " movement " for transmission.

All these sorts of Kiirqais, Aristotle points out {De anima 415 b 22 ff.), are derived from Soul ; they are not found apart from Soul. This is because Soul is the Cause (atVia) and principle {apxq) of the living body : it is alike its Motive Cause, its Final Cause and its Formal Cause {ibid. 415 b 8 ff.), and it is situated in the heart. We must not forget, however, that in the long run klvt^ois, at any rate Kivrjais of inorganic things, is due to the L'nmoved Mover, from whom " movement " is mediated by the heavenly bodies to the Lower Cosmos (App. A §§ 3 ff.) ; and even in the case of living things (" things

" Move- (51 ment" derived from Soul,

and from the Unmoved Mover.


GENERATION OF ANIMALS with Soul in them "), the heavenly bodies act as a Motive Cause, for " man is begotten by man and by the Sun " (see App. A §§ 6, 9).

Veieai^, yiyi€cr6ai (52) Tevems. as we have already seen (§ 47), is a process Meaning, of change ; in fact, it is the most fundamental sort of change, viz., " coming into being " ; hence, the product resulting from a process of yeveais is some ovaia, for although some sorts of ovaia persist eternally, there are others which are " perishable," i.e., which are subject to yo-effts and iOopd (see App. A §§ 1, 1-2, 16). Indeed, the sort of ovaia produced by the yeveai? with which our present treatise is concerned - animals and plants - is the ovaia which Aristotle considers to have the best claim to the name (App. A § 18).

(53) Teveais, and its verb yiyveaSai, are terms of frequent Translation. occurrence in Aristotle, and especially in G.A. In the title of the treatise, yiveais is commonly translated " generation," and this is a Convenient rendering of it there : but we must not forget that yeveois also refers to the whole process of an animal's development until it has reached its completion ; that is to say, yeveais includes the whole subject of reproduction and embryology. In the body of the treatise " generation " is often not satisfactory as a translation ; nor is " coming-to-be" particularly neat or indeed appropriate in a biological work. I have therefore commonly used " formation," " process of formation " and the like to render yevcai?, and for yiyv€a6ai " to be formed," " to come to be formed," etc.

SwicTTarai, (rvvi(TTaucrdai (54) Another verb closely connected with yiyveaOai is the Meaning, verb owioTovoi, which might almost be regarded as the active voice of yiyveadai, though avviaravai tends rather to refer to the beginning of the process. It is specially frequent in passages describing the initial action of the semen in constituting a " fetation " out of "the menstrual fluid of the female, and it is also used by Aristotle to describe the action of rennet upon milk, a parallel Ixi

ARISTOTLE instance which he cites bj^ way of illustration (739 b 23). 'Lvvi.aTdvai therefore denotes the first impact of Form upon Matter, the first step in the process of actualizing the potentiality of Matter. The meaning of avviardvai therefore is plain enough, but there is no really conand venient English word to translate it ; and in consequence translation. makeshift devices have to be adopted. Sometimes I have used " constitute," sometimes " set," sometimes " cause to take shape " ; and for avviaraaOai, which is also very frequent, " set " (intransitive), " take shape," " arise," etc. I decided against " composit," chiefly because I found it essential to introduce the term " fetation " for Kvrjfia {<ja'.), and as the two so often occur together, the outlandish phrase " composits the fetation " would have been frequently occurring. Nevertheless, it would have represented Aristotle's thought much more precisely, and for that reason alone I am convinced that it would have been amply justified. "Organ- (55) Another possible rendering would have been " organizers." i2e " ; and indeed " organizers " is a term which has recently been introduced into embryology to denote substances which are responsible for bringing about the differentiation of the parts of the embryo. It is interesting in this connexion to note that Aristotle seems to be working on a similar theory in G.A. IV, viz., that there is a KivTjais {i.e., a specific " movement," implying a Bvvafiis or specific substance) for each part of the body, which brings about its development in the embryo. We should, however, note that the " organizers " are not found until after impregnation is effected, whereas the distinctive " movements " proper to sensitive Soul are ex hypothesi already in the semen.

" Feta- (56) This is a term which occurs very frequently in G.A. At tion": 728 b 34 we read that by KVTfiia is meant " the first (or (a) in sexual primary) mixture of male and female " ; and although gdneia ion , ^j^^ ^^^^^ .^ ^^^^^ often so used, it is also used by Aristotle to include more than this. Actually it covers all stages of the living creature's development from the time when the " matter " is first " informed " (a common phrase is Ixii

GENERATION OF ANIMALS KVTjfjLa owiaraTai ; see § 54) to the time when the creature is born or hatched. Hence we find Kvrjfia applied to the embryo or fetus of Vivipara : to the " perfect " eggs of birds and to the " imperfect " eggs " of Cephalopods, etc. (733 a 24 : they are still so* called after deposition), to the roe of fishes (741 a 37), and to larvae (758 a 12) ; indeed, the larva is compared with the earliest stage of the Kvrjfia in viviparous animals (758 a 33).

(57) In all the foregoing cases, the " matter " for the Kvijua is (6) in sponsuppiied by the female parent : but in the case of taneous spontaneous generation there is of course no female generation ; parent, and the Kvrifj.a is formed, e.g., out of the seawater by the pneuma acting upon it (762 b 17).

(58) There are, however, some KVTjfxara which never reach the (c) infertile point of hatching (e.g., " wind-eggs ") ; thus a KVTjfxa fetations; is not necessarily fertilized. Such a Kiirqfia is, however, to some extent " informed " and can develop up to a point because it possesses nutritive Soul potentially.

(59) There is no English word which covers the wide range of the term xvrj^a, and I have therefore introduced the term " fetation," by which I invariably translate it.

(60) Aristotle holds that the seeds of plants are " as it were a (rf) fetaKvrjfjLa, because in them male and female are not separ- tions of ated : hence the seed of a plant begins with the male P^^^^ts. factor and the female factor already mixed in it : and that is why only one stalk or plant can be formed from one seed : there is no such op}x>rtunity available, as there is in the case of animals, for the male dynamis to " set " numerous fetations out of the material supplied.

Nourishment, Residues, etc.

(61) Several important terms in Aristotle's technical vocabulary are connected with the processes through which the food passes in the living body, and therefore an account of these processes will most conveniently explain the meaning of the terms.

(62) After mastication, the food passes into the stomach. Concoction, where it is " concocted " * by means of the " natural (or " See also § 77 below.

  • The Greek word for concoction is the same as that employed to denote the proceas of ripening or maturing of fruit, com and the like by means of heat - also that of baking and cooking (see


ARISTOTLE vital) heat " resident there. Any living thing (anything " with Soul in it ") possesses " natural heat," and the chief seat of the Soul and the source of the vital heat is the heart (or its analogue). But also, every part of the body as well has its own natural heat (c/. 784 b 26 ff.), derived from the heart through the blood : thus, the stomach concocts the nourishment before passing it on to the heart, and other parts may concoct it still further when the heart has sent it on to them. Beside the stomach, tlie liver and the spleen assist in the concoction of the nourishment {P.A. 670 a 20 ff.). Blood. (63) Having received its first stage of concoction in the stomach, the nourishment passes on to the heart, where as we should expect it undergoes the most important stage of its concoction, and is thereby turned into blood, the " ultimate nourishment " for the whole body {P.A. 647 b 5, rf. 666 a 8). It is probable that, in Aristotle's " Pneuma- view, an important part of this process was the " pneuma tization" of tization " of the blood (see App. B §§ 31, 32), i.e., the blood. charging of it with "EvfufivTov Ilvevfia and with the special " movement " requisite to enable it (a) to maintain the " being " of the animal and (6) to supply its growth. Two grades (64) These two functions of nourishment, and the consequent of nourish- di.stinction of two grades of nourishment, which is made inent. ^^, Aristotle at 744 b 33 ff. (where see note ; and cf. list of passages in the Index), enable us also to distinguish the different classes of residues. The first-grade nourishment (a), which is described as " nutritive " and " seminal," provides the whole animal and its parts with " being " ; the second-grade (b) is described as " growthpromoting," and causes increase of bulk. In the development of the embryo, it is the leavings of the fir-st-grade nourishment, or " nutritive residue," left over after the " supreme parts "^flesh and the other sense-organs - have been provided for, which are used to form the bones and sinews ; the second-grade, inferior, nourishment (which is taken in by way of supplement from the mother or from outside) is used to form nails, hair, horns, etc. The latter is more " earthy " 715 b 24, n.). Indeed, the processes are regarded by Aristotle as being fundamentally identical. (Cf. 743 a 31 ff.) It is also applied by him to the " maturing " of the embryo (719 a 34).


GENERATION OF ANIMALS than the former; indeed, with such residue in mind, Aristotle can say (745 b 19) that " residue is unconcocted substance, and the most unconcocted substance in the body is earthy substance " ; see also § 66 below.

(65) Generally, then, more blood Is produced than is required Residues : for the purposes mentioned at the end of § 63, and the surplus may then undergo a further stage of concoction, and Nature is often able to turn it to some useful purpose (cf. § 8 above). These are the useful " residues," and (a) useful; Nature has provided each with its proper place (G.A.

125 b 1) ; indeed, it is only in its proper place that each " residue " is formed (739 a 2). Examples of useful residues are semen, menstrual fluid, milk. Marrow, which gives the backbone coherence and elasticity, is produced when " the surplus of bloodlike nourishment is shut up in the bones " and concocted bj- their heat (P. A . 652 a 5, a 20). Sometimes, when the nourishment is particularly abimdant, the surplus blood is concocted into fat, such as lard and suet (651 a 20). Also, some of the blood, reaching the extremities of the vessels in which it is carried, makes its way out in the form of nails, claws or hair." (66) Residues may appear at various stages (725 a 13) ; they (b) ambigumay appear before, as well as after, the nourishment ous ; has been turned into blood ; and then they are residues of " nourishment at its first stage " ; thus (653 a 2, cf. 458 a 1 If.), after a meal, the nourishment rises as vapour through the vessels to the brain, where it is cooled, and then condenses into phlegma and iclior (serum). But both of these, it seems, may also be useless residues, for at 677 b 8 phlegma is mentioned in company with " the sediment- from the stomach," though perhaps it is most often a residue of the useful nourishment (725 a 14). Ichor, too, the " watery part of the blood," is sometimes unconcocted blood, sometimes corrupted blood (653 a 2 ; cf. 458 a 1 if., 651 a 15 ; no doubt et n oAAo roiovrov at O.A. 725 a 15 refers to ichor).

(67) Residues, then, are " the surplus of the nourishment " (c) useless ; " The Aristotelian doctrine of " residues " came down to Shakespeare, as is shown by the passage in Hamlet (III. rv), where the Queen saya to Hamlet : " Your bedded haire, like life in excrements, Start up, and stand an end." Ixv


(d) unnatural : Colliquescence.

(724 b 26) ; but there are useless as well as useful residues, for residue may come either from the useful or the useless nourishment (725 a 4). Useless nourishment is " that which can contribute nothing further to the natural organism, and if too much of it is consumed it causes very great injury to it " (725 a 5 ff.). Among the useless residues are the excrements ; these are natural useless residues ; but there are also some unnatural ones, as has already been hinted. Among them perhaps should be included bile, which serves no useful purpose whatever. It is a residue produced by the liver (677 b 1), it is the residue of blood in those animals which are made out of less pure blood ; it is merely a "necessary" product, an " offscouring," a " colliquescence." Colliquescence {aviTrjyfia, avvnj^is) is defined at 724 b 26 if. as that which is produced as an dnoKpLms from the material that supplies growth, as the result of decomposition proceeding contrary to Nature " (to CLTTOKpidev €K Tov av^TjfjLaros VTTO T-^s vapa <f>vat.v dvaXvaeois). Colliquescence, then, is an unnatural residue," and therefore there is no proper place set apart for it by Nature (725 a 1) ; it just runs about wherever it can in the body. (See also 726 a 1 1 ff.) Colliquescence is a very common term in the Hippocratic treatise irepi Sialrrjs, where its effect is said to be the production of an unhealthy dnoKpiais (abscession), and both there and in Aristotle dTroKpiais is specially associated with residues, useful, or useless, or even harmful ones. A great deal of it. hialrr^s is taken up with suggestions for getting rid of harmful d-noKpians. Generative (68) The most important residues so far as G.A. is concerned residues. are of course semen and menstrual fluid ;' natural and useful residues, for which Nature has set apart special places in the body. The difference between them is one of degree of concoction : semen is a residue of the final stage of useful nourishment (726 a "iQ) ; so is menstrual fluid (738 a 36), but the female has not sufficient natural heat to carry the concoction far enough to produce Source of semen. Hence, the difference between male and female " It seems however that a " colliquescence " may sometimes be a natural residue, for at P. A. 677 a 13 bile is said to be " a residue or a colliquescence," and it is classed with the sediment in the stomach and intestines. See also P. A. (Loeb ed.), pp. 38 f.


GENERATION OF ANIMALS is to be traced back to the innermost source of the sex-dififerorganism, viz., the heart : the sexual organs may serve ^nce is the as an outward expression of the difference, but the difference is not due to them. Like the blood, of which it is a more fully concocted form, semen derives its character primarily from the heart, where the blood is pneumatized and charged with the requisite specific " movements " (see § 63 and G.A. 737 a 19). Semen, therefore, like blood, is the vehicle of " Soul," and especially so in virtue of the Sv/x^vrov Ilveu/ia which it contains, for SvV<Ai""ov Ilvevfia is the physical substance with which Soul is most intimately " associated." In terms of Soul, the difference between semen and menstrual fluid is that semen possesses the principle of sentient Soul, menstrual fluid possesses only nutritive Soul (potentialh) : the fiuid has not been charged with the " movement " proper to sentient Soul owing to deficiency of heat in the female. The other " movements" in these generative residues are a most important factor in the determination of generic, specific, sexual, and even individual characteristics : see the discussion in G.A. IV. 766 a 13 ff., 767 b 15 flF. (69) It should be noted that the heat both of blood and of Heat of semen (the concocted residue of blood) is not inherent, l^'ood and but is acquired from a source other than themselves, ^o"^.*" The logos of blood, it is true, includes the term " hot," herent but but only in the same sense that the logos of " boiling "acquired.' water " (if we had one word for that as we have for blood) would include the term " hot." In other words, the permanent substratum of blood is not hot ; and thus, although in one way blood is " essentially " hot, in another way it is not " essentially " hot {P. A. 649 b 21 ff.). Similarly, the " matter " of semen is " watery " (/.(?., the substratum of it is the Element Water; cf. 736 a 1 and preceding passage) ; and its heat is a supplementary acquisition {eiriicnp-os : G.A. 747 a 18, rf. 750 a 9, 10). The explanation of these statements, as will be obvious from the preceding sections, is that blood is produced by the heat of the heart out of the fluid matter supplied by the stomach from the food (§ 63), and semen of course has to undergo still further concoction bv the vital heat in the appropriate parts (§ 62).


ARISTOTLE Two modes of difference ; Blood ; Classijicaiion of Animals (1) "The (70) Differences " by the more and less," or " of excess and more and deficiency " - differences of degree, as we should say, ®*- are minor differences such as are found as between different species of one and the same genus or of any larger group. Thus {P. A. 644 a 19, 692 b 24) the parts of birds differ in this way, some having long legs, or feathers, others short ones ; some a broad tongue, others a narrow one. Again, the male will have the same defensive or offensive organ as the female, but " to a greater degree," and this sometimes holds good of organs essential for food and nutrition " (661 b 28 ff.). Difference " by the more and less " can also be applied to skin, blood-vessel, membrane, sinew : these are substances which differ among themselves in this way {G.A. 737 b 4 ; cf. 739 b 32). (2) (71) Where the divergence is wider, as for instance between 'Counter- different groups of animals such as birds and fishes, par s. j.j^g difference is no longer ru) iiaXXov Koi â– ^ttov, but to) avaXoyov (P. A. 644 a 21) : the corresponding parts, e.g., the feathers of birds, the scales of fishes, and the scales of reptiles, differ " by analogy," i.e., they are merely the " counterparts," the " opposite numbers " of each other, as indeed the large groups of animals themselves may be (see G.A. 761 a 27 and context ; cf. also 784 b 16 ff., and 737 b 4, n.). (72) Many examples of this usage occur in G.A. ; we find mention of to avaAoyov of the heart ; of the blood, and of the menstrual fluid, in bloodless creatures ; of teeth ; of flesh ; of fat ; of hair ; of sinew. Menstrual fluid in females is dvdXoyov to semen in males (727 a 3) ; we might have expected this difference to be only a difference " by the more and less," but no doubt the reason why it is a wider divergence is that menstrual fluid lacks sentient Soul (see § 68). The most frequent references to TO dvdXoyov in G.A. are the counterparts of the heart and of the blood. And the most important of all the counterparts is of course " the substance in the pneuma, " Cf. the view that the female is a " deformity," § 13. Ixviii

GENERATION OF ANIMALS which is avaXoyov to the element of the stars, alther (736 b 37).

(73) It should be noted that by " blood " Aristotle means red Blood, blood only, and he makes a division of animals into " blooded " {evaifia) and " bloodless " (avaifia). These two classes do not quite coincide with vertebrates and invertebrates, for there are some invertebrates which have red blood, e.g., molluscs {Planorbis), insect larvae (Chironomvs), and worms (Arenicola). In other invertebrates the blood may be blue (Crustacea and most moUuscs) or green (Sabellid worms), or there may be no respiratory pigment at all (most Insects).

(74) The following table shows how Aristotle's division Blooded works out : ^uLai Blooded animals Bloodless animals animmls.

Man. Crustacea.

Viviparous quadrupeds. Cephalopods.

Oviparous quadrupeds and Insects, footless animals ( = rei>- Testacea.

tiles and amphibians).


Fishes. It may be convenient to give here the Greek names used by Aristotle for the four classes of Bloodless animals, together with their literal translation and the terms which I have used to translate them : TO. fiaXoKooTpaKa soft-shelled animals Crustacea. ra fuxXaKia softies Cephalopods.

ra evTOfjLa insected animals Insects.

TO. oarpoKohfptia shell-skinned animals Testacea." (75) The Testacea were a source of considerable embarrass- The ment to Aristotle, who considered them to be inter- Testacea. mediate between animals proper and plants. Nor, according to him, did they reproduce sexually, but arose from spontaneous generation. In his treatise on the Progression of Animals, he defers mention of them to â– ' In using " Testacea " to translate ri o<rTpaxoJepua (" the animals with earthenware skins ") I use it in the old-fasliioned sense, so as to include a number of shelled invertebrates, comprising Gasteropods, Lamellibranchs, and some Echinoderms. Modem zoologists apply the term Testacea to the Foraminifera, which are shelled Protozoa. The term Ostracoderms (a transliteration of Aristotle's word) is now given by zoologists to a group of primitive fossil fishes.



Claasiflcation according to method of reproduction.

' ' Perfect animals.

Distinction of ' ' perfect" and "imperfect" «gg«.

Distinction of egg and larva.

the very end and then says that strictly speaking they ought not to move about at all, yet in fact we see them moving : anyway, their movement is " contrary to nature," because they " have no right and left ." (The mechanism of their movement can be detected only by the microscope, and is known as ciliary.) (76) In G.A., however, although Aristotle adheres to his classification into Blooded and Bloodless animals, perhaps a more important classification is that which is based upon their method of reproduction. This classification will be found in the Contents-Summary, pp. Ixii ff. And in this connexion we must notice that the list is headed by the Viviparous animals, of which the first is Man : these are the " most perfect animals," and therefore they produce their offspring in the most perfected condition. And by " most perfect " (732 b 29) Aristotle means the animals which are " in their nature hotter and more fluid {vyporepa), and are not earthy " ; and, as the test of natural heat is the presence of the lung, and further, a lung well supplied with blood, no animal can be internally viviparous unless it respires. (See the whole passage 732 a 26- 733 b 16.) (77) It should be noted that Aristotle clearly distinguishes between what he calls " perfect " and " imperfect " eggs, that is to say between eggs which do not and those which do increase in size after deposition. This is the basis of the modern distinction between cleidoic and non-cleidoic eggs (see 718 b 7, n.). He also clearly distinguishes between an egg and a larva : an egg is that from part of which the young creature is formed, the remainder serving as nourishment for it ; a larva is something of which the ichole is used to form the young animal. (See 732 a 29 and note, and 758 b 10 flF.) The fact that Aristotle drew these distinctions so clearly is particularly noteworthy. He was, of course, unaware of the existence of the mammalian ovum, which cannot be detected without the aid of the microscope. It should also be noted that Aristotle compares the growth of a non-cleidoic egg with the action of yeast in fermentation ; see 755 a 18.




1. 1 The Causes. The Motive and Material Causes of animals are the main theme of G.A.

The Sexes

(a) Distinction of sexes not universal. They are {a) found in mast blooded animals, and in Cephalopods and Cnistacea, but not in all Insects ; (b) not found in Testacea. 2 (6) Definition of male and female : they are the " principles " of generation, the male pro\iding the motive agent and the female the material. Hence a corresponding difference in the sexual parts, which vary in the various animals, but are always double.

1 - Sexual Parts in Blooded Animals

4 (a) Sexual parts in males. The purpose of testes.

8 (b) Sexual parts in females :

(1) Ovipara laying imperfect eggs.

(2) Ovipara laying perfect eggs.

10 (.3) OvoNipipara (Selacliia and vipers).

(4) Tivipara. 12 (c) Further remarks on position of sexual organs.

2 - Copidation of Bloodless Animals

14 (a) Crustacea.

15 (6) Cephalopods (including reference to the hectocotvlized arm of the Octopus).

16 (c) In.sects : some (1) are generated by copulation, copulate, and produce larvae ; some (2) are generated spontaneously, copulate, and produce larvae ; some (3) are generated spontaneouslv and do not copulate.

(1) includes locusts, cicadas, spiders, wasps, ants ; (2) fleas, flies, cantharides ; (3) gnats, mosquitoes, etc.

3 - Theory of Sexual Generation

17 (A) What is the nature of semen ?

(a) Theory of "pangenesis" examined and refuted bv various arguments.

(b) Definition of semen : it is that " from " which natural objects are produced. It is one of the " residues " - a residue of the useful nourishment in its final form - not a colliquescence.

19 (B) Menstrual fluid. Tliis also is a residue, similar to semen, but less concocted. It is the matter for generation. Since the male p^o^^des the form, se\-eral offspring may be originated by one semen.

21 (C) (a) Elaboration of the theory of generation.


I. 22 (b) The female cannot generate alone because it cannot provide the form (viz., sentient Soul). Semen is the " instrument " used by Nature, charged with the " movement " wliich conveys the form. 23 (c) Comparison and contrast of animals and plants. Sexes arc not separate in plants because reproduction is almost their only function.

II. 1 (D) The Final Cause of the existence of the Sexes. They sub serve generation, the perpetuation of the species, and this is the way by which " perishable " things are able to partake in eternal " being."

Classification of the various methods of Generation

Note on the difference between an egg and a larva.

The classes (Vivipara, Ovovivipara, Ovipara laying perfect egg, Ovipara laying imperfect egg, Larvipara) do not correspond to differences in the organs of locomotion, but to the degrees of " perfection " of the animals concerned, the most perfect being those which are hot, as is shown by the fact that they breathe.

(1) Animals that are hot and fluid. Viviparous. Man, (2) Animals that are cold and fluid. Ovoviviparous. Selachia and vipers.

(3) Animals that are hot and solid. Oviparous (perfect egg). Birds and scaly animals.

(4) Animals that are cold and solid. Oviparous (imperfect egg). Fishes, Crustacea, Cephalopoda.

(5) Animals that are coldest of all. Larviparous." Insects.

3 (resumed) - Theory of Sexual Generation

(a) What is the agent that fashions the embryo ? Preformation versus epigenesis. It is the male parent, or rather the semen in which the parent's " movement " is transmitted, which fashions the embryo. Thus the material (provided by the female), which is potentially a living body of a particular kind, is gradually actualized. The parts of the body - and of the Soul - are actualized successively : first the heart and nutritive Soul.

2 (b) The physical character of semen. It is a foam, a com pound of Water and pneutna.

3 (c) Does semen contain Soul ? Yes - potentially ; all the sorts of Soul which act through a body must be present first of all potentially. The problem of the entry of rational Soul.

(d) The physical substance in which Soul is carried is pneuma, a " divine " substance analogous to aither, the fifth element.

(e) Jlenstrual fluid contains all the parts of the body potentially, but it lacks sentient Soul.

a The larva represents a stage previous to that of the egg, for, according to Aristotle, the larva develops into an egg-like object.


Generation Of Animals

Generation in Blooded Animals - I. Vivipara


II. 4 Man and the " perfect " animals.

(a) The secretion of the generative residues. Semen is not produced by all male animals.

(b) The male - either by means of semen or directly - " sets " the purest portion of the female's residue and so produces a fetation.

(c) The development of the fetation. The heart is formed first, as being the seat of nutritive Soul.

(d) Theory of the action of the male factor on tin? female. Nutritive Soul ases heat and cold as " instruments."

5 (e) The female cannot generate alone because it lacks sentient Soul (in some animals, however, the sexes are not separate).

6 (f) Later development of the fetation. The upper parts develop first (but not so in Insects and C'ephalopods).

(g) The differentiation of the parts is effected by means of connate pneuma.

(h) The order of development of the parts.

(i) The bloodvessels ; the " uniform " parts ; nails, etc. ; sinews and bones. ,

(j) Heating and cooling are employed as instruments in the development of the fetation. Necessity and purpose.

{k) The brain ; the eyes.

(l) Bones, etc.

(m) Two grades of nonrishment : " nutritive " and " growthpromoting."

(n) Teeth.

7 (o) Function of the umbilicus and cotyledons.

(p) Hybrids ; sterility ; mules ; deformed animals.

Generation in Blooded Animals - II. Ovipara {laying perfect eggs)

III. 1 Birds and Quadrupeds.

(a) Greneral.

(b) Wind-eggs.

(c) Difference between yolk and white : the white is hot and is the seat of the Soul-principle.

2 ((f) Shape of the egg.

(e) Growth of the egg.

(/) Incubation by parent animal (not needed for quadrupeds'

(g) Behaviour of white and yolk during incubation. (h) Description of the umbilical cords, etc.

Generation in Blooded Animals - III. Ovovivipara (laying perfect eggs)

3 Fishes (A) Selachia.

(o) Description of the development of the embryo. (b) Differences as between Birds and Selachia (including reference to Miutelus laevis).

Generation in Blooded Animals - IV. Ovipara {laying imperfect eggs)


III. 4 Fishes (B) Fishes other than Selachia.

(a) Growtli of the egg : a process comparable with fermentation.

5 (6) Erroneous theories : ( 1 ) Fisti are not oviparous and have no sex distinction ; (2) swallowing of milt ; 6 (3) apocryphal methods of copulation in birds ; (4) stories about trochos and hyena.

7 Method of action of male birds and male fishes upon the eggs contrasted.

Generation in Bloodless Animals

8 (A) Cephalopods and Crustacea.

9 (B) Insects.

(a) The larva is comparable to the earliest stage of an egg. All Insects, whether formed as a result of copulation , or by spontaneous generation, originate from larvae.

(b) Development of the larva.

10 (c) Bees. Hornets and Wasps.

11 (C) Testacea : intermediate between animals and plants.

Various animals proper to the various Elements. Moonand Fire-animals.

(a) Side-shoot (quasi-seminal) propagation, etc.

(b) Spontaneous generation : the action of pneuma. The theory expounded. Traditional view of the origin of animals. The process of development resembles that of larvae. Examples of spontaneous generation.

Origin of Sex-differentiation in the Individual and Inheritance

IV. 1 (a) Various theories : Anaxagoras, Empedocles, Democritus, Leophanes. (b) The fundamental distinction between male and female is that the male can concoct and discharge semetf ; the female cannot concoct or discharge semen, but can receive it : the difference of the sex-organs is consequent upon this distinction, and therefore the sex of the developing embryo is so too. Thus the ultimate source of sex-distinction is the heart, which provides the vital heat necessary for concoction. Further statement on the difference of formation of the sexual organs.

2 (c) Facts cited to support theory.

(d) Impprtance of (TvntL^Tpia, both internally and ext€mally (" blend " of climate).

3 («) Resemblance to parents. Theory of inheritance. (Jf) Fallings away from type : Male changes over to female. Father changes over to mother.

IV. 3 Relapses : Father to grandfather, then to greatgrandfather, etc. Mother to grandmother, then to greatgrandmother, etc. This is applicable to the parts as well as to the whole tiody. (g) Furthet departures : unevenly developed individuals. (A) Earlier theories of resemblances examined. (»■) Monstrosities : (1) fancied resemblance to animals ; 4 (2) with redundant parts ; (3) deficient in parts. (j) Connexion of this with the number of young produced. (k) Reason for the redundance of parts. (0 Other irregular formations.


5 Superfetation.

6 Degree of perfection of the young at birth.

In human beings, more males bom deformed than females. The female itself is a deformity, though a natural deformity.

7 The mola uteri.

8 Milk. The heart controls the production of milk, a.s it does the production of the voice. >Iilk is concocted blood.

9 Animals are bom head first.

10 Length of gestation-period. The periods of animals are governed by cosmic periods.

Secondary Characteristics

V. 1 Introductory. This part of the work is concerned with characteristics which are due entirely to Necessity (i.«., the Motive and Material Causes), and in no way to the Final Cause.

(a) Embr>-os are mostly asleep.

(6) Colour of eyes.

(e) Keenness of sight, due (1) to the amount of fluid in the eyes ; (2) to the condition of the skin on the pupil. There are two senses of " keenness " : ability to see at a distance ; ability to distinguish colours.

2 (d) Keenness of smell and hearing.

Digression on the inner mechanism of the senses.

3 (e) Hair : thickness, curliness, rigidity, baldness and moulting.

4 (/) Colour of hair, in man, and in other animals.

6 (g) Coloration of animals. Colour of tongue. Seasonal colour-changes. General remarks on colour.

7 (A) Voice.

8 (t) Teeth : order of growth, etc.

(j) The relation of the Material and Motive Causes (Necessity) to the Final Cause.

Abbreviations Used in this Volume

Works of Aristotle

H.A. Historia animalium

Phys. Physica

P. A.

De partibus anima







De generatione ani





Ethica Nicomachea


De incessu anima




De an.

De anima


De motu animalium

De resp.

. De respiratione

G. 4f C. De generatione et corruptione

Other Works

L. & S. Liddell and Scott's Oreek-Engliah Lexicon (1925-1940)

Diels, Vorsokr. Die Fragmente der Vorsokratiker, by Hermann Diels, fifth ed., edited by W. Kranz, 1934-1937

C.Q. Classical Quarterly

C.Ii. Classical Review

Other abbreviations are self-explanatory.


  • Preface
    • Aristotle's Embryology
    • Early Translations
    • The Text
    • Modern Editions
    • The Translation
    • Acknowledgements
  • Contents-Summary of De Geseratione animalium
  • Abbreviations
  • Text axd Translation
  • Table of Birds
    • Diagram of Embryonic Membranes
  • Additional Notes on the Text
  • Additional Notes on the Subject-Matter
  • Appendix A
  • Appendix B
  • Index

Z Oxoniensis Collegii Corporis Christi W.A. 2. 7.

S Laurentianus Mediceus 81, 1.

P Vaticanus graecus 1339.

Y Vaticanus graecus 261.

Manvscripts occasionally cited m Parisinus 1921.

O*' Riccardianus 13.

E Parisinus 1853.

All Mss. readings are as reported by Bekker (by Bussemaker for E at 723 b 5 and 769 b 34, and for m at 723 b 5 and 768 b 36)' except that

  • denotes corrected or additional reports of readings as

given by Bitterauf (and twice only, for Z at 768 b 36 and 786 a 3, as given by Susemihl).

Readings and emendations Z Michael Scot's Latin translation (either its actual words, or the original Greek reading clearly implied), from my own transcription.

Gul. William of Moerbeke's Latin translation.

Aldvis The Aldine editio princeps, Venice, 1497.

vulg. The usual reading, as in the Berlin edition.

Buss. Bussemaker, in tiie Didot edition.

A.-W. Wimmer, in Aubert and Wimmer's edition.

Sus. Susemihl.

Btf. Bitterauf.

Rackham Suggestions in private communications to me by Mr. H. Rackham.

Emendations and proposals by other scholars are attributed to them by name (for references see pp. xxvii f.).

[ ] Denote words wrongly placed or incorporated into the text.

< > Denote (a) in the Greek text, words or parts of words supplied conjecturally ; (b) in the English, either the translation of words supplied in the Greek, or words required to complete the sense.

<• Z', Z', etc. = first hand, second hand, of Z, etc. Ixxviii

Ciascuna cosa qual ella e diventa.


Book I

With one exception we have now " spoken about I all the parts * that are present in animals, both gener- {fon"'^"'^' ally concerning them, and also taking them group by group and dealing separately with the parts peculiar to each, and have shown in what way each part exists on account of the Cause which is of a corresponding kind : I refer to the Cause which is " that for the sake of which " a thing exists." As we know, there are four basic Causes ** : (1) " that for the sake of which " the thing exists, considered as its " End " ; (2) the logos * of the thing's essence (really these first two should be taken as being almost one and the same) ; (3) the matter of the thing, and (4) that from which comes the principle f of the thing's movement. And with one exception I have already spoken about all of these Causes, since the logos of a thing and " that for the sake of which " it exists, considered as its End. are the same ; and, for animals, the matter of them is their parts (the non-uniform ^ parts are the matter for the animal as a whole in each case ; the uniform parts are the matter for the non-uniform parts ; and the corporeal " elements," ° as they are called, are the matter for the uniform parts). Consequently, of the parts it remains to describe those which subserve animals for the purpose of generation, about which I have so far said nothing definite, and of Causes we still have the Motive Cause to deal with, and to explain what it is. And, in a way, consideration of this Cause and consideration of the generation of each animal comes to the same thing : and that is why our treatise has brought the two together, by placing these parts at the end of our account of the parts, ** and by putting the beginning of the account of generation immediately after them.

Now of course some animals are formed as a result Distinction of the copulation of male and female, namely, animals uni\^ereaL°*^ belonging to those groups in which there exist both male and female, for we must remember that not all groups have both male and female. x\mong the blooded "^ animals, with a few exceptions, the individual when completely formed is either male or female ; but among the bloodless animals , while some groups have both male and female and hence generate offspring which are identical in kind with their parents, there are other groups which, although they generate, do not generate offspring identical with their parents. Such are the creatures which come into being not as the result of the copulation of living animals, but out of putrescent soil and out of residues.* ' Speaking generally, however, we may say that (a) in the case of all those animals which have the power of locomotion, whether they are adapted to be swimmers, or fliers, or walkers, male and female are found ; and this applies not only to the blooded animals but to some of the bloodless ones as well. And among the latter, in some cases it holds good of a whole group, as for instance the Cephalopods and the Crustacea " ; and it holds good of most of the Insects. Among animals of this class, those which are formed as the result of the copulation of animals of the same kind, themselves generate in turn after their o^vn kind ; those, however, which arise not from h\-ing animals but from putrescent matter, although they generate, produce something that is different in kind, and the product is neither male nor female. Some of the Insects are Uke this.** And this is what we should expect ; for supposing that creatures which are produced other^^ise than from Uving animals copulated and produced Uving animals : if these products were similar in kind to their parents, then the manner of their parents' original generation should have been like theirs. This we may reasonably claim, because it is e\ident that this is so \rith all other animals. If, on the other hand, the products were dissimilar from their parents, and yet able to copulate, we should then get arising from them yet another different manner of creature, and out of their progeny yet another, and so it would go on ad infimtum. Nature, however, avoids what is infinite, because the infinite lacks completion and finality, whereas this is what Nature always seeks, (b) The creatures which cannot move about, Uke the Testacea and those which live by being attached to some surface, are in their essence similar to plants, and therefore, as in plants, so also in them, male and female are not found, although they are called male and female just by way of similarity and analogy, since they exhibit a slight difference of this sort. Thus among plants also we find that in one and the same kind some indi\idual trees bear fruit, while some, although they do not bear any themselves, assist in the concocting * of that which is borne by the others. An instance of this is the fig and the caprifig.* '^ [The same sort of thing is found in plants too : some are formed out of seed, others as it might be by some spontaneous activity of Nature - they are formed when either the soil or certain parts ** in plants become putrescent, since some of them do not take shape ^ independently on their own, but grow upon other trees, as for instance the mistletoe does.] flowers as they leave the inflorescence, and then pollinate female flowers elsewhere. Caprification is the name given to the artificial assistance of this process by hanging inflorescences of the caprifig on to trees of class (1). The growers believe that the fruit of the Ficus is improved by the wasps ; but in fact excellent fruit is produced by these trees without pollination, though of course no fertile seerLf. Hence caprification must be a traditional usage dating from the time when fertile seeds were required for propagation, which is now done bv means of cuttings. See Kerner and Oliver, Natural History of Plants, ii. 160-162 ; H. MuUer, Fertilization of Flowers, tr. p. 521 and bibliography. Cf. H.A. 557 h 26 ff., where the wasp is mentioned.

  • The following sentence is obviously out of place here, as is shown (a) by the opening words, which must mark the beginning of a reference to plants, whereas here plants are already being discussed ; and (6) by its inappropriateness to the particular point under discussion. It would be relevant if transferred to 715 a 25. Cf. H.A. 539 a 16 fl".
  • Cf. 762 b 19.
  • See Introd. § 54.

Still, plants will have to be considered independently all by themselves.

As far as animals are concerned, we must describe II their generation just as we find the theme requires of*^a\e°° for each several kind as we go along, Unking our »nd female. account on to what has already been said. As we mentioned, we may safely set down as the chief principles of generation the male (factor) <* and the female (factor) ; the male as possessing the principle of movement and of generation, the female as possessing that of matter. ** One is most likely to be convinced of this by considering how the semen is formed and whence it comes ; for although the things that are formed in the course of Nature no doubt take their rise "^ out of semen,** we -must not fail to notice how the semen itself is formed from the male and the female, since it is because this part * is secreted from the male and the female, and because its secretion takes place in them and out of them, that the male and the female are the principles of generation. By a " male " animal we mean one which generates in another, by " female " one which generates in itself. This is why in cosmology too they speak of the natiu-e of the Earth as something female and call it " mother," while they give to the heaven and the sun and anything else of that kind the title of " generator," and " father." Now male and female differ in respect of their The gexaai logos/ in that the power or faculty possessed by the p*^ • one differs from that possessed by the other ; but they differ^ also to bodily sense, in respect of certain physical parts. They differ in their logos, because the male is that which has the power to generate in another (as was stated above), while the female is that which can generate in itself, i.e., it is that out of which the generated offspring, which is present in the generator," comes into being. Very well, then : they are distinguished in respect of their faculty, and this entails a certain function. Now for the exercise of every function instruments are needed, and the instruments for physical faculties are the parts of the body. Hence it is necessary that, for the purpose of copulation and procreation, certain parts should exist, parts that are different from each other, in respect of which the male will differ from the female ; for although male and female are indeed used as epithets of the whole of the animal, it is not male or female in respect of the whole of itself, but only in respect of a particular faculty and a particular part * - ^just as it is " seeing " and " walking " in respect of certain parts - and this part is one which is evident to the senses. Now in the female this special part is what is called the uterus, and in the male the regions about the testes and the penis, so far as all the blooded animals are concerned : some of them have actual testes, some testicular passages. There are also differences between male and female in those of the bloodless creatures which have this opposition of the sexes. In the blooded animals the parts which serve for copulation differ in their shapes. We must note, however,'^ that when a small principle '^ changes, usually many of the things which depend upon it undergo an accompanying change." This is clear with castrated animals, where, although the generative part alone is destroyed, almost the whole form of the animal thereupon changes so much that it appears to be female or very nearly so, which suggests that it is not merely in respect of some casual part or some casual faculty that an animal is male or female. It is clear, then, that " the male." and " the female " are a principle. At any rate, when apimals undergo a change in respect of that wherein they are male and female, many other things about them undergo an accompanying change, which suggests that a principle undergoes some alteration.

The testicles and the uterus are not of similar III arrangement in all the blooded animals. Consider first the males, and their testicles. Some blooded animals (as the groups of Irishes and Serpents) have no testicles at all, only two seminal passages. ° Others have testicles, but they are inside, by the loin, near the place where the kidneys are ; from each of them runs a passage (as in those animals which have no testicles), and these two passages join up together (again like those other animals) : among the class of animals which breathe air and have a lung, this occurs in all the Birds and in the o\'iparous quadrupeds, for all these as well have their testicles inside, by the loin, and two passages leading from them, just as the Serpents have : examples are the lizards, the tortoises, and all the animals with homy scales. All sex hormones from the interstitial cells of the testis and ovary respectively.

  • These are in fact the testes, but Aristotle reserves this name for the firm, oval-shaped testes. This negative statement does not of course include the cartilaginous fishes, the Selachia, many of which are viviparous.

the Vivipara, however, have their testicles in front,** though some of them have them inside by the end of the abdomen^ - e.g., the dolphin- and have no passages, but a sexual duct* which leads from them to the outside, as the ox-fish "^ have ; while some have the testicles outside, and of these some are pendent (as in man), others fastened by the fundament (as in swine). I have given a more accurate account of these in the Researches upon Animals.'^ The uterus * is always double without exception, just as in males there are always two testes >^'ithout exception. In some animals the uterus is by the pudenda (as it is in women and in all animals that are \-iviparous internally as well as externally, and such of the fishes as lay their eggs lisibly) ; in other animals the uterus is up towards the diaphragm ^ (as it is in all birds and in the \iviparous fishes). The Crustacea, too, and the Cephalopods have a double uterus, since the membranes which surround their " eggs " ' as they are called are uterine in nature.

The uterus is particularly indistinct in the Octopuses, so that it appears to be single. The reason for this is that the whole bulk of the creature's body is of similar consistency throughout. In the large supposes poes here to be "oxen." A.-W. translate " \vie die Stiere." <* See H.A. Bk. Ill, ch. 1.

  • It should be noted, once for all, that this term includes what are now known as oviducts.
  • Aristotle does not confine his use of this term to mammals, which alone have a diaphragm in the usual sense of that term, and hence it must be understood to refer also to the corresponding position in lower animals, as in the present passage ; cf. also iJe respirations 475 a 8, where the viro^iofia of wasps, crickets, etc., is mentioned.

Insects too the uterus is double, whereas in the smaller ones it is indistinct on account of the smallness of the creatures' body.

This describes the arrangement of those parts of animals which I have mentioned.

Returning to the subject of the difference of the IV seminal organs in various groups of male animals : blooded If we are to consider the causes to which this is due, animau : we must first of all understand the purpose for the parts i^ sake of which " testes exist. If we agree that every- °^'* ' thing which Nature does is done either because it is necessary or else because it is better, we should expect to find that this part, Uke the rest, exists for one or the other of these two reasons. Now it is evident that it is not necessary for generation, otherwise all animals that generate would have it, whereas actually neither Serpents nor Fishes have testes, and these do in fact generate, because they have been observed copulating, with their passages full of milt. The other reason then remains : testes exist for some purpose - because it is better that they should exist. Now the business of most animals may be summed up pretty much as that of plants is - viz., seed and fruit; and,, just as (to take a parallel case) animals which have straight intestines are more violent in their desire for food," so here also, animals which have no testes but passages only, or which have testes but not external ones, are all quicker with the business of copulation. Those, however, which have to be more sober (a) in the case of feeding, have not straight intestines, and (b) in the case of copulation, have passages which are twisted,** so that their desire shall not be violent or speedy. This then is the object for which the testes have been contrived : they make the movement of the seminal residue more steady. (1) In the ^'i\ipa^a, as for instance in horses and other such animals, and also in man, they do this by maintaining in position the doubling-back of the passages (for a description of this reference must be made to the Researches upon Animals),'^ since the testes are no integral part of the passages : they are merely attached thereto, just like the stone weights which women hang on their looms when they are wea\-ing. ^ When the testes are removed, the passages are drawn up within ; this is why castrated animals cannot generate, whereas if the passages were not so drawn up they would be able to do so. A bull immediately after castration has been kno\\'n to mount a cow and effect impregnation,"^ because the passages had not yet been drawn up. (2) In Birds and in the oviparous quadrupeds the testes receive the seminal residue, so that its emission is slower than it is in the case of Fishes. This is clearly to be seen in Birds : their testes are much larger at the time of copulation.* Those birds which copulate at one season only of the year have such tiny testes when this period is over that they are almost indistinguishable, whereas during the breeding season they are very big. So then the animals whose testes are internal accomplish their copulation more quickly, since in fact those with external testes do not emit the semen until the testes have been dravvn up.

Another point. The organ for copulation is present V in the quadrupeds because it is possible for them to have it, whereas it is not possible for birds and footless animals. It is impossible for birds " because their legs are under the middle of the abdomen. It is impossible for the other creatures because they have no legs at all, and that is the place where the penis is always suspended and that is the position for it. (This also is the reason why there is strain on the legs during sexual intercourse : both the organ itself and the legs are by their nature sinewy.) And so, since it is impossible for them to have this organ, they must of necessity have no testes either, or else not have them in that place, since in those animals which possess both penis and testes the situation of both is one and the same.

Another point. As far as the animals with external testes are concerned, as the penis is set in movement and gets heated, the semen first collects itself together, and then advances : it is not ready immediately contact is established, as it is in fishes.^ All the Vivipara have their testes in front, [or outside,*^] except the hedgehog. This is the only one that has them by the loin,** and the reason is the same as for the birds,*' since they must of necessity accomplish their copulation quickly, for they do not mount on the back as the other quadrupeds do, but on account of their spines stand upright for intercourse.

We have now said why those animals which have testes have them, and why some have them outside

  • This remark, if it remains in the text, obviously cannot refer to the only reason so far given for birds at 717 b 15-1,7 ; if taken as referring to the reason which immediately follows, this will roughly correspond to the statement in II.A. o39 b 34 that some birds copulate quickly. But no doubt the reason Aristotle has in mind is th^ one mentioned below at 719 buff., viz., that the skin is too hard.

and others inside. And as for those which have no M testes, they lack this part, as we have said, because such absence is not good, but necessary merely '^ ; and also because it is necessarj' that their copulation should be accomphshed quickly. Fishes and serpents come under this class. Fishes copulate bv placing themselves alongside each other and quickly ejaculate.* Just as men and all such animals "^ in order to emit the semen must of necessity hold their breath, so fishes must refrain from taking in the seawater,** and when they omit to do this they easily come to grief. On this account they are bound to avoid concocting * the semen during the act of copulation (which is what the \i\iparous land-animals do) ; instead, they have their semen ready concocted and collected at the proper time, so that they do not concoct it while in contact \\-ith each other, but emit it already concocted. For this reason they have no testes, but passages which are straight and simple. In the testes of quadrupeds there is a small portion of a similar character : I refer to the latter portion of that length of the passage which is doubled back.' One portion of this length has blood in it and one has not, and by the time the fluid enters this latter portion and passes through it, it is already semen ; so that when it arrives there, ejaculation quickly takes place * in these animals too. In Fishes the whole of the passage is of the same character as this latter portion of it in man and other such animals (i.e., the latter portion of that length of it which is doubled back).

Serpents copulate by twisting round each other, VII but they have no testes and not even a penis, as I said earlier : no penis, because they have no legs either," and no testes because of their length - instead, they have passages just as fish do - since as their bodies are so very long, if there were to be yet further delay in the region of the testes, the semen would be cooled off owing to its slow rate of progress. This does in fact happen with men who have a large penis : they are less fertile than those who have a moderately large one, because the semen gets cooled off by being transported too great a distance, and cold semen is not generative. I have now stated why some animals have testes and others not.

  • [Serpents intertwine because they are not naturally fitted for placing themselves alongside each other ; their bodies are so long, and the part by which they unite is so small, that they find difficulty in achie\'ing union ; and so, as they have no parts by which they can take hold of each other, they make use of the suppleness of their bodies instead, and t\^ist around each other. On this account, they seem, too, to take longer to ejaculate than fish do, not only because of the length of the passages but also because of the intricacy of the manoeuvre.]

One may well be puzzled concerning the arrange- VIII ment of the uterus in the various female animals ; C^) sexual many instances of quite contrary arrangements female.

conclusion of the chapter, the remarks which follow are probably a supplementary note, or an alternative version, incorporated in the text.

occur. To begin with, not all the Vivipara have the same arrangement. All that are land-animals, including human beings, have the uterus placed low down by the pudenda, whereas the v'iviparous Selachia " have it higher up by the diaphragm. x\nd then again, the Ovipara show the same variations. Fishes have the uterus low down Uke human beings and the vi\iparous quadrupeds, whereas birds have it higher up, and so do the oWparous quadrupeds. Nevertheless, there is rhyme and reason even in these contradictory phenomena. First of all, the egglaying animals have different ways of laying their eggs, (a) Some creatures' eggs are imperfect when laid - e.g.. those of fishes, which become perfected. i.e., grow, outside the creature which produces them.^ The reason is that these animals are very prolific and this is their function," as it is that of plants ; so that if they brought the eggs to a state of perfection inside their bodies, the eggs would of necessity be few in number, whereas in actual fact they produce so many that each uterus seems to be just one mass of ^gg, at any rate in the very small fishes, which are the most prolific of all. The same is true both of those plants and of those animals which are of a corresponding nature ** in their own classes ; what carbohydrates, etc.) to make each an embryo, are insufficiently supplied with water and inorganic materials ; these they have to absorb from their environment. Hence their swelling. Though the main bulk of this is due to waterintake, it is interesting that the greater part of the copper, for example, which i.b present in the respiratory bloodpigment of the octopus at the time of hatching is derived, not from the egg as laid, but from the surrounding sea-water. See also 732 b 5, etc

would have produced increase of size is in them diverted to form seed, (b) Birds, however, and quadrupedal Ovipara lay eggs that are perfect," and these eggs for safety's sake are bound to have a hard skin (while they are still growing, they have a soft skin), and the shell is formed by heat, which evaporates the fluid from the earthy substance ; hence the place where this is to be done must of necessity be hot - a condition which is fulfilled by the region round the diaphragm, as the fact that it concocts the food shows. So, if the eggs must of necessity be within the uterus, the uterus must of necessity be alongside the diaphragm in those animals whose eggs are in a perfected condition when laid, while it must be low down in those whose eggs are imperfect when laid ; it will be advantageous so. Further, it is more natural that the uterus should be low down than high up (unless there is some other business of Nature's which prevents it), since its conclusion is down below too ; and where the conclusion is, there also the function is ; thus the uterus is where the function is.

Similarly, the Vivipara differ from one another. IX Some of them bring forth their young alive not externally only but also within themselves,*' as for instance, human beings, horses, dogs and all haired animals, also such water-animals as dolphins, whales and such cetacea. Selachia and Vipers, though they bring forth their X young alive externally, first of all produce eggs internally. And the egg they produce is a perfected one, for thus only is an animal generated from the egg : nothing is generated from an imperfect egg. The reason why they do not lay their eggs externally is because thev are by nature cold creatures, not hot, as some persons allege." Anyway, the eggs they XI produce are soft-skinned - because the creatures have so httle heat in them that their natural constitution does not dry oiFthe outermost part of the eggs. Thus the coldness of the creatures is the reason why the eggs they produce are soft-skinned, and the fact that the eggs are soft -skinned is the reason they are not produced externally : if they were, they would come to grief.

When the animal is formed out of the egg, the process of formation is for the most part the same as for birds : (the eggs) descend, and the young animals are formed close by the pudenda, as occurs also in creatures which are viviparous right from the outset. Another result of this is that in animals such as we are now discussing the uterus differs both from that of the Vivipara and from that of the Ovipara, since they have a share in both these groups ; that is to say, in all the Selachians the uterus is at the same time close by the diaphragm and also extends along do\vnwards. (However, to ascertain the arrangement of the uterus of the Selachians and other kinds as well, the Dissections ^ should be inspected and also the Researches '^). Thus the Selachians have their uterus high up because they are oviparous and lay perfected eggs, while they have it low down because they are Niviparous ; thus they have a share in both.

function that prevents this, nor do they produce their young by the two-stage process." Besides, it is impossible for young animals to be formed near the diaphragm ; embryos are bound to be hea\y and to move about, and that part of the body is a vital spot and would not be able to put up vvith such things. Further, (if the uterus were placed high,) parturition would of necessity be difficult on account of the distance to be covered, since even as it is, in the case of women, if they draw up the uterus at the time of parturition by yav\-ning or by doing something of the sort, difficulty in delivery is the result. Even when empty the uterus produces a stifling sensation if ' pushed upwards. Besides, a uterus which is destined to contain (not an egg but) an actual animal must of necessity be a stronger thing ; that is why the uterus of all viviparous animals is fleshy, whereas in those cases where it is near the diaphragm the uterus is membranous. This is clearly to be seen in the case of those animals which produce their young by the two-stage process : the eggs are carried high up and towards one side, whereas the young creatures are carried in the lower part of the uterus.

We have now explained the reason why contrary arrangements of the uterus are found in certain animals, and in general why in some the uterus is placed low down and in others high up by the diaphragm.

We have seen too that while all animals have their XII uterus inside, some have their testes inside and others re^n^rkf*^ outside. The reason whv the uterus is alwavs inside is that it is the container for the voung creature while it is being formed, and this needs protection, shelter, and concoction,^ which the outer part of the body

cannot provide, being easily injured and cold. The testicles, however, are inside in some animals but outside in others : since, however, they also need shelter and covering to keep them safe and to secure concoction for the semen (for if they have been exposed to cold and rendered stiff they cannot be drawn up and emit the semen), those animals whose testes are in the open have a covering of skin over them known as the scrotum ; while those animals the nature of whose skin is so hard that it is not amenable to this arrangement, and cannot be used for a WTapping and is not soft or Uke ordinary skin (e.g., animals whose skin is like that of fish, and those whose skin is made of horny scales) - they must of necessity have their testes inside. On this account the dolphins and those cetacea which possess testes have them inside ; so do those horny-scaled animals which are o\-iparous and four-footed. Birds, too, have hard skin, which will not accommodate itself to the size of the testes and make a wrapping for them, and this makes another reason why in all these cases the testes are inside in addition to the reasons (previously mentioned") due to the necessary exigencies of copulation. And for this selfsame reason the testes are also inside in the elephant and in the hedgehog ; the skin of these two animals, as of the others, is not well adapted for having the protective part separate. [Contrary positions of the uterus are found in those animals which are internally vi\iparous and in those which are externally oviparous ; and again in some of the latter class it is placed low down, in others by the diaphragm, as for instance in fishes on the one

  • The following paragraph is simply a hash-up of parts of the preceding chapters.

hand as against birds and o\"iparous quadrupeds on the other ; and then again it is different in those aniniak which produce their young by both of the two methods, \'iz., which are internally o\iparous and outwardly \'i\i parous. Those animals which are both internally and externally vi\iparous have their uterus placed against the abdomen, as for iastance man, ox, dog, and other such animals, since it is expedient for the safety and growth of the embryo that no weight should be put upon the uterus.] In all these animals the passage through which the XIII solid residue issues is other than that through which the fluid issues. On this account all such animals, both male and female, have pudenda by which the fluid residue is voided, and thereby too in males the semen passes out and in the females the fetation.** This passage is situated higher up than the passage for the solid nourishment and in front of it. [Those animals which lay eggs, but lay imperfect ones, e.g., the o\"iparous fishes, have their uterus not under the abdomen but by the loin, since the growth of the egg causes no obstruction, because the groAnng object icomes to its perfection and makes its advance outside Ithe animal.] In all those animals which have no pudendum which serves for generation, this passage is the same as that for the solid nourishment, \-iz., in all the 0\ipara, including those 0\ipara which have a bladder, e.g., the tortoises. The existence of tno passages, it must be remembered, is for the sake of generation, not for the sake of voiding the fluid residue, and it is only because the semen is fluid in nature that the residue from the fluid nourishment shares the use of the same passage. This is clear from the fact that although all animals produce semen, fluid residue is not formed in all of them.

Now in males the seminal passages must have a fixed position and not stray about, and the same is true of the uterus in females ; and this fixed position must of necessity be either towards the front or the back of the body. Hence, (a) in the \'i\ipara the uterus is in front, on account of the embryo ; (6) in the Ovipara it is by the loin and at the back ; (c) in those animals which begin bv producing eggs within themselves and later bring their young forth externally, both positions are found combined, because the animals share the characteristics of both classes ; they are viviparous and oviparous ahke ; thus, the upper portion of the uterus, in which the eggs are formed, is below the diaphragm by the loin, and towards the back ; but its continuation is lower down, by the abdomen, for from this point onwards the production of live young begins. In these animals also there is one passage only for the solid residue and for copulation ; none of them has a pudendum projecting from the body, as has been said before. What is true of the uterus in Ovipara is true also of the passages in the males, both those which have testes and those which have not. In all of them the passages are fastened towards the back near the region of the spine ; fastened, because they may not stray about, but must have a settled position, which is just what the back part of the body provides ; it gives continuity and stability. Indeed, in those animals which have their testes inside, the passages acquire their fixed position at the very outset [at the same time as the passages] ; and similarly in those animals whose testes are external. Afterwards they meet and unite towards the region of the pudendum. The arrangement of the passages is the same as this in dolphins, although their testes are hidden below the abdominal cavity.

We have now described the situation of the parts which are concerned with generation in the blooded animals and have stated the causes.

In the other class of animals, viz., the bloodless XIV ones, the manner of the parts concerned with genera- bloodless tion is quite different from what it is in the blooded animals. ones ; and what is more they differ among themselves. We have here four groups still left to deal with : (1) Crustacea, (2) Cephalopods, (3) Insects, (4) Testacea (with regard to all of these the facts are obscure, but it is plain that most of them do not copulate " ; as for the manner in which they arise, we must describe this later on).^ (1) The (i) CrusCrustacea copulate as the retromingent animals do : one lies prone and the other supine and they fit their tail-parts one tp the other. The males are prevented from mounting the females belly to back by their tail-parts which have long flaps attached to them. The males have narrow seminal passages, and the females have a membranous uterus by the side of the gut, divided on either side, and in this the egg is formed. (2) The Cephalopods copulate by the XV • mouth, pushing against each other and intertwining (2) Cephatheir tentacles. This manner of copulation is due to necessity, because nature has bent the end of the residual passage so as to bring it round by the side of the mouth, as I have previously said [in the treatise on The Parts of Animals].'^ The female of each of these animals has a part like a uterus, which is plain to be seen ; it contains an eg^ which at first is indistinct,^ but later divides up and is formed into a number of eggs, each of which the creature deposits in an imperfect state, just as the oviparous fishes do. In these animals as well as in the Crustacea the passage which serves for the residue and connects with the uterus-like part, is one and the same (it is on the under surface of the body, where the " mantle" Ues open and the sea water enters in '^). Hence it is through this that the male effects copulation with the female, since if the male discharges anything, be it semen, or some part,** or some other substance,* he must of necessity unite with the female through the passage which leads to the uterus. In the case of the Octopuses, the male inserts his tentacle through the funnel of the female, and the fishermen allege that copulation is effected by means of this tentacle,^ but its purpose is really to link the two creatures together ; it has no instrumental use so far as generation is concerned, because it is outside the passage (of the male) and outside his body.^ mantle of the female. Aristotle however does not explicitly mention this detaching of the arm.

Sometimes too Cephalopods copulate while both creatures are lying prone, but it has not yet been observed whether this is done for the purpose of generation or for some other cause.

(3) As regards Insects, some of them copulate, and XVI in those cases the young are generated from animals ^^^ insects. which are of the same name " and nature as themselves, just as happens in the blooded creatures ; instances of this are locusts, cicadas, spiders, wasps, ants. Others, although they copulate and generate, generate not creatures of the same kind as themselves but only larvae ^ ; and these insects moreover are not produced out of animals at all but out of putrefying fluids (in some cases, solids) ; instances of this are fleas, flies, cantharides. Others neither are produced out of animals nor do they copulate ; such are gnats, mosquitoes "^ and many similar kinds of insects. In most of the sorts which copulate the females are larger than the males ; and the males do not seem to have any seminal passages. Speaking generally, the male does not insert any part into the female ; but the female does so into the male upwards from below : this has been observed in many instances, [and similarly as concerns mounting,] the opposite in a few ; but we have not yet enough observations to enable us to classify them distinctly. We find that the females are larger than the males not only in Insects but also in most of the oviparous fishes, and likewise in those quadrupeds which are oviparous ; the reason being that the size is an advantage to them when a great bulk is produced inside them by the eggs at the time of breeding. In the females the part that answers to the uterus is divided and extends alongside the gut, as in other animals ; this is where the fetations are formed. This can be clearly seen in locusts and in any insect whose nature it is to copulate, provided it is large enough ; most insects however are too small." Such is the manner of animals' instrumental parts connected vvith generation, which I had not dealt with in my previous treatise. ** Of the " uniform " '^ parts, semen and milk were there left undescribed, and the time has now come to speak of these. We v\ill deal with semen without delay, and with milk in the chapters which are to follow.*^ Some animals discharge semen plainly, for instance XVII those which are by nature blooded animals ; but it '^^'""â– is not clear in which way Insects and Cephalopods do so. Here then is a point we must consider : Do all male animals discharge semen, or not all of them ? and if not all, why is it that some do and some do not ? and further. Do females contribute any semen, or not ? and if they contribute no semen, is there no other substance at all which they contribute, or is there something else which is not semen ? And there is a further question which we must consider : What is it which those animals that discharge semen contribute towards generation by means of it ? and generally, what is the nature of semen, and (in the case of those animals which discharge this fluid) what is the nature of the menstrual discharge .^ It is generally held that all things are formed and Theor>.

come to be out of semen, and semen comes fromofpanthe parents. -And so one and the same inquiry will examined. include the two questions : (1) Do both the male and the female discharge semen, or only one of them ? and (2) Is the semen drawn from the whole of the parent's body" or not ? - since it is reasonable to hold that if it is not drawn from the whole of the body it is not drawn from both the parents either. There are some who assert that the semen is drawn from the whole of the body, and so we must consider the facts about this first of all. There are really four Unes of argument which may be used to prove that the semen is drawn from each of the parts of the body. The first is, the intensity of the pleasure involved ; it is argued that any emotion, when its scope is widened, is more pleasant than the same emotion \t-hen its scope is less wide ; and ob\iously an emotion ^ . which affects all the parts of the body has a wider scope than one which affects a single part of a few parts only. The second argument is that mutilated parents produce mutilated offspring, and it is alleged that because the parent is deficient in some one part no semen comes from that part, and that the part from which no semen comes does not get formed in the offspring. The third argument is the resemblances shown by the young to their parents : the offspring which are produced are like their parents not only in respect of their body as a whole, but part for part too ; hence, if the reason for the resemblance of the whole is that the semen is drawn from the carriers of heredity move centripetally from all the parts of the body to the germ, thus involving the inheritance of acquired characteristics (for which inheritance, however, there is no evidence). - See also Hippocrates, -nepl depcav vSarcov roTTUiv 16. " Cf. 724 a 9-10.

whole, then the reason for the resemblance of the parts is surely that something is drawn from each of the parts. Fourthly, it would seem reasonable to hold that just as there is some original thing out of which the whole creature is formed, so also it is with each of the parts ; and hence if there is a semen which gives rise to the whole, there must be a special semen which gives rise to each of the parts. And these opinions derive plausibility from such e\"idence as the following : Children are born which resemble their parents in respect not only of congenital characteristics but also of acquired ones " ; for instance, there have been cases of children Avhich have had the outline of a scar in the same places where their parents had scars, and there was a case at Chalcedon of &. man who was branded on his arm, and the same letter, though somewhat confused and indistinct, appeared marked on his child. These are the main pieces of evidence which give some people ground for beUe\ing that the semen is drawn from the whole of the body.

Upon examination of the subject, however, the XVIII opposite seems more likely to be true ; indeed, it is not difficult to refute these arguments, and besides that, they involve making further assertions which are impossible. First of all, then, resemblance is no proof that the semen is drawn from the whole of the body, because children resemble their parents in voice, nails, and hair and even in the way they move ; but nothing whatever is drawn from these things ; and there are some characteristics which a parent does not yet possess at the time when the child is , generated, such as grey hair or beard. Further, children resemble their remoter ancestors, from whom nothing has been drawn for the semen. Resemblances of this sort recur after many generations, as the following instance shows. There was at Elis a woman who had intercourse with a blackamoor ; her daughter was not a black, but that daughter's son was. And the same argument will hold for plants. We should have to say that the seed was drawn from the whole of the plant, just as in animals. But many plants lack certain parts ; vou can if vou wish pull some of the parts off, and some parts grow on afterwards. Further, nothing is drawn from the pericarp to contribute to the seed, yet pericarp is formed in the new plant and it has the same fashion as that in the old one.

Here is a further question. Is the semen drawn dnly from each of the " uniform " parts of the body, such as flesh, bone, sinew, or is it drawn from the " non-uniform " parts as well, such as face and hand ? Consider the possibilities : (1) The semen may be drawn from the uniform parts only. If so, (then children ought to resemble their parents in respect of these only,) but the resemblance occurs rather in the non-uniform parts such as face, hands? and feet. Therefore if even these resemblances in the non-uniform parts are not due to the semen being drawn from the whole body, why must the resemblances in the uniform parts be due to that and not to some other cause ? (2) The semen may be drawn from the non-uniform parts only. This means that it is not drawn from all the parts. Yet it is more in keeping that it should be drawn from the uniform parts, because they are prior to the non-uniform, and the non-uniform are constructed out of them ; . and just as children are born resembling their parents in face and hands, so they resemble them in flesh and nails. (3) The semen may be drawn from both uniform and non-uniform parts. The question then arises : What can be the manner in which generation takes place ? The non-uniform parts are constructed out of uniform ones assembled together ; so that being drawn from the non-uniform parts would come to the same thing as being drawn from the uniform parts plus the assemblage of them." (It is just Uke the case of a word written down on paper : if there were anything drawn from the whole of the word, it would be drawn from each of the syllables also,** and this of course means that it would be dra^Ti from the letters plus the assemblage of them together.) Now flesh and bones, we should agree, are constructed out of fire and the like substances  ; which means that the semen would be drawn from the elements only, because how can it possibly be drawn from the assemblage of them ? And yet without this assemblage the parts would not have the resemblance ; so if there is something which sets to work later on to bring this assemblage about, then surely this something, and not the drawing of the semen from the whole of the body, will be the cause of the resemblance.

Further, if the parts of the body are scattered about within the semen, how do they live ? If on the other hand they are connected with each other, then surely they would be a tiny animal. x\nd what about the generative organs ? " because that which comes from the male will be different from that which comes from the female.^ Further, if the semen is drawn from all the parts of both parents alike, we shall have two animals formed, for the semen will contain all the parts of each of them. If this sort of view is to be adopted, the statement most closely in accord with it appears to be that of Empedocles [at any rate up to a point ; if we take any other view, he appears wrong]. Empedocles says that in the male and in the female there is as it might be a tally - a half of something - and that the whole is not drawn from either of the parents. " But " (I quote his words) torn asuiider stands The substance ' of the limbs ; part is in man's . . .** Otherwise the question arises, why is it that female animals do not generate out of themselves, if so be that the semen is drawn from the whole body and a receptacle for it is at hand } No ; so far as we can see, either the semen is not drawn from the whole body, or if it is, it happens in the way described by Empedocles - the two parents do not both supply the same portions, and that is why they need intercourse with each other. But even Empedocles' explanation is impossible. The parts cannot remain sound and living if " torn asunder " from each other when small, any more than they can when they are fully grown. Empedocles, however, implies that they

can when he says in his account of their generation during the " Reign of Love," * There many neckless heads sprang up and grew * ; later on, he says, they grew on to each other. This is clearly impossible : on the one hand, if they had not Soul '^ or life of some sort in them they could not remain safe and sound ; and on the other hand, if they were a number of separate living animals, as one might say, they could not groAv on to each other so as to become one animal again. Yet this is actually the kind of thing which those people have to say who allege that the semen is drawn from the whole of the body ; just as it was in the beginning in the earth in the Reign of Love, so it is, according to them, in the living body.** Of course it is impossible that the parts should become connected, i.e., come off from the parents so that they go together into one place.* Besides, in any case, how were the upper and lower parts, the right and left, the front and the back, " sundered " ? All these ideas are fantastic.

Further, among the parts, some are distinguished by some faculty they possess, others by ha\'ing certain physical quaUties f : thus, the non-uniform parts (such as the tongue or the hand) are distinguished by possessing the faculty to perform certain actions, the uniform parts by hardness or softness or other such qualities. Unless, therefore, it possesses certain special qualities, a substance is not blood or flesh ; and hence it is plain that the substance which is ' One of the definitions of Trddos given at Met. 1022 b 15 is " a quality (ttoiottjs) in virtue of which a thing may be altered, e.g., whiteness, blackness, heaviness, lightness, etc."

drawn from the various parts of the parent has no right to the same name " as those parts - we may not call that " blood " which is drawn from the parents' blood, and the same ^^ith flesh. This means that the offspring's blood is formed out of something which is other than blood, and if so, then the cause of its resemblance will not be due to the semen's being drawn from all the parts of the parent's body, as the supporters of this theor}' assert - because if blood is formed from something that is not blood,* the semen need only be drawn from one part, there being no reason why all the other constituents as well as blood should not be formed out of the one substance. This theory seems to be identical ^yiih that of Anaxagoras,'^ in asserting that none of the uniform substances comes into being ; the only difference is that whereas he applied the theor}' universally, these people apply it to the generation of animals. Again, how are these parts which were drawn from the whole of the parent's body going to grow ? Anaxagoras gives a reasonable answer ; he says that the flesh alreadv present is joined by flesh that comes from the nourishment. Those people however, who do not follow Anaxagoras in the statement just quoted, yet hold that the semen is drawn from the whole bodv, are faced with this question : how is the embrvo to grow bigger bj' the addition of different substance to it which the embryo takes in afterwards also contains these substances. Hence the theory gets into a difficulty when the question arises of how the growth of the embrjo is effected. This difficulty is avoided by Anaxagoras, because he makes his principle " a portion of every element in every thing " apply nniversally, and does not limit its application to the semen onlv. (For Anax., see A. L. Peck, C'. XXV { 1931 ), 27 ff., 112" if.)

unless the substance that is added changes ? If however it is admitted that this added substance can change, why not admit straight away that the semen at the outset is such that out of it blood and flesh can be formed, instead of maintaining that the semen is itself both blood and flesh ? They might try to argue that it grows at a later stage by admixture, just as wine is increased in bulk by pouring in water ; but even this line of argmnent proves impossible, because if that were so, then it would surely be at the outset that each of the parts was its own proper self, before it was mixed, whereas in actual fact it is at a later stage that this occurs (I refer of course to flesh and bone and every one of the rest of them). And the assertion that some of the semen is sinew and bone is quite beyond us, as the saying goes.

Here is another objection. Suppose it is true that the differentiation between male and female takes place during conception, as Empedocles says " : Into clean vessels were they poured forth ; Some spring up to be women, if so be They meet with cold. . . .

Anyway, both men and women are observed to change : not only do the infertile become fertile, but also those who have borne females bear males ; which suggests that the cause is not that the semen is or is not drawn from the whole of the parents, but depends upon whether or not that which is drawn from the man and from the woman stand in the right proportional relation to each other. Or else it is due to some other cause of this sort. Thus, if we are to assume this as true, viz., that the same semen is

able to be formed into either male or female <* (implying that the sexual part is not present in the semen), it is clear that it is not the semen's being drawn from some one part which causes the offspring to be female, nor, in consequence, is it responsible for the special physical part which is peculiar to the two sexes. And what can be asserted about the sexual part can equally well be asserted about the other parts ; since if no semen comes even from the uterus, the same will surely hold good of the other parts as well.

Further, some animals are formed neither from creatures of the same kind as themselves nor from creatures of a different kind ; . examples are : flies and the various kinds of fleas as they are called. Animals are formed from these, it is true, but in these cases they are not similar in character to their parents ; instead we get a class of larvae. Thus in these creatures which differ in kind from their parents we clearly have animals which are not formed out of semen dra>\"n from every part of the body, for if resemblance is held to be a sure sign that this has occurred, then they would resemble their parents.

Further, even among the animals there are some which generate numerous offspring from one act of coition, a phenomenon which is, indeed, universal with plants ; these, as is manifest, produce a whole season's fruit as the result of one single movement. Now how is this possible on the supposition that the semen is secreted from the whole body ? One act of coition, and one effort of segregation, ought necessarily to give rise to one secretion and no more. That it should get divided up in the uterus is impossible,

for by that tirae the division would be made as it were from a new plant or animal, not of semen. <* Further, transplanted cuttings bear seed - derived, of course, from themselves : which is proof positive that the fruit they bore before they were transplanted was derived from that identical amount of the plant which is now the cutting, and that the seed was not drawn from the whole of the plant.

The weightiest proof of all, however, we have sufficiently established by our observations of Insects. Perhaps not in all Insects, but certainly in most, during copulation the female extends a part of itself into the male [so, as we said earlier,* this is actually the way in which they effect copulation] : the females can be seen inserting something into the males upwards from below. This does not applv to all Insects, but to most of those which have been observed. Hence surely it is clear that even in the case of those males which discharge semen generation is not caused by the semen's being drawn from the whole of the body, but it is brought about in some other way, which we must consider later on. And indeed, if it were really true that the semen is di-awn from the whole body, as these people say, there would still be no call for them to assert that it is drawn from all the parts ; they need only say it is drawn from the creative part which does the fashioning - from the artificer, in other words, not from the material which he fashions. As it is, they talk as though even the shoes which the parent wears were included among the sources from which the semen is drawn, for on the whole a son who resembles his father wears shoes that resemble his.

It is true that there is intense pleasure in sexual intercourse. The cause of this however is not that the semen is drawn from the whole body, but that there is violent stimulation ; and that of course is why those who indulge often in such intercourse derive less pleasure from it. Moreover, the pleasure in fact comes at the end, but according to the theory it should occur (a) in every one of the parts, and (6) not simultaneously, but earher in some and later in others.

As for mutilated offspring being produced by mutilated parents, the cause is the same as that which makes offspring resemble their parents. And anyway, not all offspring of mutilated parents are mutilated, any more than all offspring resemble their parents. The cause of these things we must consider later * ; the problem in both cases is the same.

Moreover, if the female does not discharge any semen, then it is consistent to say that the semen is not drawn from the whole body either ; or again, if it is not drawn from the whole body, there is nothing inconsistent in saying that it is not drawn from the female either,* but that the female is responsible for generation in some other way than this. This, in fact, vriW be the next subject for us to investigate, now that it is clear that the semen is not secreted from all the parts of the body.

We must begin this investigation and those which Definition are to follow by discovering first of all what semen is ; this will enable us to consider more easily its functions and everything connected with it. Now the aim of semen is to be, in its nature, the sort of stuff from which the things that take their rise in the realm of Nature are originally formed." There are, however, numerous senses in which one thing is formed or comes into being " from " another * : (1) as we say " from day comes night," and " from boy comes man," meaning that the one comes after the other ; (2) as a statue is formed from bronze, or a bedstead from wood, and all those cases where we describe things as being formed from some material ; here the finished whole has been fashioned into a certain shape from something which was there to begin ^\^th ; (3) as a person may become uncultured from being cultured or ailing from healthy, i.e., all cases of a contrary coming from its contrary ; (4) as in a " cumulative " passage in Epicharmus '^ : e.g., from slander comes abuse, from abuse a fight ; in all these cases " from so-and-so " means that so-and-so is the source of the movement,** and in some instances Ls also abundantly clear from the argument which immediately follows.

of this sort the source of the movement is within the things themselves, as in the ones just quoted (where slander is actually one part of the whole to-do) ; in others it is external to them ; e.g., craftsmanship of every kind is external to the works which the craftsman produces, and the torch is external to the house which is set on fire.

Now it is clear that the case of semen falls under one or other of these two senses " : the offspring is formed " from " it either (a) as " from " material, or (b) as " from " a prime mover (a source of movement). It is definitely not an instance of (1) above, where " from " means " after," e.g., " from the Panathenaean festival comes the sea-voyage " ; nor of (3), i.e., of coming into being " from " a contrary ; for the one contrary is destroyed as the other comes into being from it, and so there must be present besides them some primary substrate, from which the new contrary is to come into being. ** Thus we now have to discover in which of the two classes semen is to be placed : Is it to be regarded as matter, i.e., as something which is acted upon, or as a form, i.e., as something which acts of itself - or even as both ? for perhaps at the same time it will also be clear in what way formation from contraries has its place in all things that arise from semen. (After all, formation from contraries as well as the other methods of formation is found in nature ; sonxg animals are formed from contraries - male and female, though some are formed from one parent only, as are plants and certain of the animals in which there is no definite separation of male and female.) out the change. Clearly, says Aristotle, this is not the meaning of yiyveaOai required here.

" [Seminal fluid is the name given to that which comes from the generating parent, in the case of those animals whose nature it is to copulate, and it is that in which a generative principle is first found. Semen (seed) is the name given to that which contains the principles derived from both the parents which have copulated, as in the case of the plants and certain animals in which male and female are not separate, Uke the first mixture which is formed fi-om the male and female, being as it were a sort of fetation or egg - for these objects too already contain that which comes from both parents.

Semen (seed) and fruit differ by the " prior and posterior ** " : fruit (is posterior) in that it is derived from something else, whereas seed <is prior) in that something else is derived from it, since in fact they are both one and the same thing.

We must now resume and state what is the primary nature of semen, as it is called.] Now every substance, whatever it may be, that we find in the body, must of necessity be one of the following : (1) one of the parts which are there in accordance with nature, in which case it will be one of the imiform or non-uniform parts ; (2) one which is there contrary to nature, e.g., a tumour ; (3) residue '^ ; (4-) colliquescence ** : (5) nourishment. By residue I mean that which is left over as surplus from the nourishment ; by colUquescence that which is given off as an abscession * from the material that supplies growth, as the result of decomposition proceeding contrary to nature. Now it is clear that semen cannot possibly be (1) one of the parts ; since although it is uniform," it does not serve as the material out of which any other parts ^ are composed, as sinew and flesh do ; nor again is it separate and distinct,^ whereas all the other parts are. Nor (2) is it something contrary to nature, or a deformation, (a) because it is present in every single individual, and (6) because the natural organism develops out of it. As for (5) nourishment, obviously this is introduced into the body from without. It must therefore be either (4) a colliquescence or (3) a residue. The early thinkers appear to have supposed it was a colliquescence, because to say that it is drawn from the whole body in virtue of the heat which the movement produces,* is equivalent to saying that the semen is a colliquescence. But colUquescence belongs to the class of things that are contrary to nature, and from such things nothing that is in accordance with nature is ever formed. Therefore the semen must of necessity be a residue. ^ ery well. Every residue results either from useful or from useless nourishment. By " useless nourishment " I mean that which contributes nothing further to the natural organism and which if too much of it is consumed causes very great injury to the organism ; " useful nourishment " is the opposite of this. It is obvious that semen cannot be a residue resulting from useless nourishment, for while residue of that sort is found in considerable quantities in those who through age or disease are in a very bad state of health, the same is not true of semen ; such persons either have none at all, or if they have, it is infertile because of the useless and diseased residue that gets mixed with it.

Hence, semen is part of a useful residue ; and the most useful of the residues is that which is produced last, that from which each of the parts of the body is directly formed. I said " last," for of course some of the residues are produced earlier, some later. Nourishment in its first stage yields as its residue phlegma and any other such stuff." Yes, phlegma too is a residue from the useful nourishment, as is shown by the fact that when it is mixed with pure nourishment it nourishes the body,^ and that the body consumes it in cases of disease. The residue which comes last, however, is very small in bulk though the nourishment which pelds it is very large '^ ; but we must bear in mind that it requires very Uttle to supply the growth of animals and plants from day to day, since the continual addition of a very small amount to the same thing would make its size excessive.

Our own statement therefore must be the opposite Semen a of what the early people said. They said the semen ^^'^"®is that which was drawn from the whole of the body ; we are going to say the semen is that whose nature it is to be distributed to the whole of the body.** And whereas they said it was a colUquescence, we see it is more correct to call it a residue. After all, it is more reasonable to suppose that the surplus residue of the final nourishment which is distributed all over the body resembles that nourishment, just as (to take a common instance) the paint left over on an artist's palette resembles that which he has actually used ; whereas everything that undergoes colhquescence gets destroyed and departs from its proper nature." Here is a piece of evidence to show that semen is not a colhquescence but a residue : the large animals produce but few young, while the small ones are prohfic. Now in the large animals there must of necessity be more colhquescence and less residue, because most of the nourishment is used up to maintain the large bulk of their body, so that but little residue is produced. Further, no place has been assigned by Nature for colhquescence, but it runs about in the body wherever it can find a clear way for itself ; whereas there is a proper place for all the natural residues - e.g., the lowef intestine ^ is set apart for the residue from title sohd nourishment, the bladder for that from the fluid, the upper intestine " for that from the useful nourishment, the uterus, pudenda, and breasts for the seminal residues - they run into these places and collect there. As evidence of the truth of our statement about what semen is we can quote the actual facts, facts which directly result from this residue's being of the nature described by us. Thus (1) though only a very small quantity of semien be emitted, the exhaustion which follows is quite conspicuous,** which suggests that the body is being deprived of the final product formed out of the nourishment. (There are, I know, a few who for a short period during the heat of youth derive rehef from the emission of the semen when it is superabundant. The same is true also of nourishment in its first stage, if there is an excessive quantity of it ; the body is more comfortable for having got rid of it. Relief is obtained too when other residues are got rid of in company viith the semen : in such cases what is emitted is not merely semen, but there are other substances which come away at the same time mixed up vvith it, and these are morbid. This explains why at certain times with some persons the emission is infertile : it contains so small an amount of actual semen. However, speaking generally for the majority of men, the sequel to sexual intercourse is exhaustion and weakness rather than relief, and the cause is as I have described.) Besides (2), semen is absent during childhood, old age, and infirmity ; absent during infirmity on account of the weakness of the body, during old age because the organism does not concoct a sufficient amount " ; during childhood because the body is grovring, and the concocted matter is all used up so soon that there is none left over : it is usually held that in about five years human beings, at any rate, grow to one-half of the complete size that they vrill attain in the rest of their lifetime. In respect of semen we find that yriih many animals and plants one group differs from another group, and even v^ithin one and the same group individuals of the same kind differ from each other, e.g., one man from another, and one grape-vine from another. Some individuals have much semen, some little, some none at all ; and this is not due to any bodily weakness, but in some cases, at any rate, it is due to the opposite : the available supply gets used up to benefit the body ; as an example of this we have men in sound health putting on rather a lot of flesh *" and getting a bit fat : these emit less semen and have less desire for sexual intercourse than is normal. A similar phenomenon is that of grape-vines which " go goaty," rampaging all over the place because they are getting too much nourishment. (The reason for the phrase " go goaty " is that they behave just like he-goats, which when they get fat indulge less in copulation, and incidentally this explains why goats are made to slim before the breeding season comes on.) And further it seems that fat people, men and women alike, are less fertile than those who are not fat, the reason being that when the body is too well fed, the effect of concoction upon the residue is to turn it into fat (since fat also is one of the residues, a healthy one, because it results from good living).

Some living things actually produce no semen at all : examples are the willow and the poplar. Both reasons together are responsible for this state of affairs ; in other words, on account of their weakness the trees cannot concoct their nourishment, and on account of their strength they use it all up, as described above. Similarly, some animals are prolific, and have abundance of semen because they are strong, but others because they are weak ; the explanation being that in the latter case much useless residue gets mixed up with the semen, and in some instances, when there is no clear way open by which the evacuated matter may leave, it actually produces disease, from which some recover though others succumb. Their semen is contaminated by the colliquescences which get into it, just as they do into the urine - another malady by no means unknown.

[Further, the same passage serves both for the residue and for the semen : (a) in those animals which

produce residue both from the fluid nourishment and from the soHd, the semen is discharged by the same exit as the fluid residue, because it is itself a residue from a fluid, the nourishment of all animals tending to be fluid rather than solid ; (6) in those animals which produce no fluid residue, the semen leaves by the same way as the solid excrement. Further, colUquescence is always morbid, whereas the removal of residue is beneficial ; and the discharge of semen has both characteristics because it includes some of the useless nourishment. If it were just a colliquescence, it would always be injurious, whereas in fact it is not so.] To conclude : the foregoing discussion makes it clear that, whether all animals discharge semen or not, semen is a residue derived from useful nourishment, and not only that, but from useful nourishment in its final form.

Our next task is to detemiine what is the character XIX of the nourishment from which this residue is derived ; Menstrual and we must discuss the menstrual discharge as well, because this occurs in some of the Vi\dpara. By this means we shall be able to give a clear answer to the following questions : Does the female discharge semen as the male does, which would mean that the object formed is a single mixture produced from two semens ; or is there no discharge of semen from the female ? And if there is none, then does the female contribute nothing whatever to generation, merely providing a place where generation may happen ; or does it contribute something else, and if so, how and in what manner does it do so ? We have said before ** that in blooded animals blood is the final form of the nourishment, and in

bloodless animals the analogous substance. And since semen also is a residue from nourishment - from nourishment in its final form, surely it follows that semen will be either blood or the analogous substance, or something formed out of these. Now every one of the parts " is formed out of the blood as it becomes concocted and in some Avay diWded up into portions ; and though semen which has been concocted is by the time of its secretion from it considerably different in character from blood, yet unconcocted semen, and semen emitted under strain due to excessively frequent intercourse, has been known in some cases to have a bloodUke appearance when discharged ; and this shows that semen is pretty certainly a residue from that nourishment which is in the fomi of blood and which, as being the final form of nourishment, is distributed to the various parts of the body.* This, of course, is the reason why semen has great potency '^ - the loss of it from the system is just as exhausting as the loss of pure healthy blood - and this, too, is why we should expect cliildren to resemble their parents : because there is a resemblance between that which is distributed to the various parts of the body and that which is left over.** Thus, the semen of the hand or of the face or of the whole animal really is hand or face or a whole animal though in an undifferentiated way ; in other words, what each of those is in actuality, such the semen is potentially,^ whether in respect of its o^\•n proper bulk, or because it has some dynamis ^ within itself (I mention both alternatives because from what we have said so far it is not clear which is the correct one,^ i.e., whether

the physical substance of the semen is the cause of generation, or whether it contains some disposition " and some principle of movement which effects generation), since neither a hand nor any other part of the body whatsoever is a hand or any other part of the body if it lacks Soul ^ or some other dynamis ; it has the same name,*^ but that is all.** [It is clear also that in cases where seminal colliquescence occurs, this too is a residue ; and this happens when (a fresh secretion) is decomposed into that which preceded it ; just as when a (fresh) layer of plaster spread on a wall immediately drops away, the reason being that the stuff which comes away is identical with that which was applied in the first instance. In just the same way, the final residue is identical with the original colliquescence. Such then are the Unes on which we treat that subject.] Now (1) the weaker creature too must of necessity produce a residue, greater in amount and less thoroughly concocted ; and (2) this, if such is its character, must of necessity be a volume of bloodlike fluid. -^ (3) That which by nature has a smaller share of heat is weaker ; and (4) the female answers to this description, as we have said already. From which we conclude that the bloodUke secretion which occurs in the female must of necessity be a residue just as much (as the secretion in the male). Of such a character is the discharge of what is called the menstrual fluid.

Thus much then is evident : the menstrual fluid is a residue, and it is the analogous thing in females to the semen in males. Its behaviour shows that this statement is correct. At the same time of life that semen begins to appear in males and is emitted, the menstrual discharge begins to flow in females, their voice changes and their breasts begin to become conspicuous ; and similarly, in the decline of hfe the power to generate ceases in males and the menstrual discharge ceases in females. Here are still further indications that this secretion which females produce is a residue. Speaking generally, unless the menstrual discharge is suspended, women are not troubled by haemorrhoids or bleeding from the nose or any other such discharge, and if it happens that they are, then the evacuations fall off in quantity, which suggests that the substance secreted is being drawn off to the other discharges. Again, their blood-vessels are not so prominent as those of males : and females are more neatly made ** and smoother than males, because the residue which goes to produce those characteristics in males is in females discharged together with the menstrual fluid. We are bound to hold, in addition, that for the same cause the bulk of the body in female Vivipara is smaller than that of the males, as of course it is only in Vivipara that the menstrual discharge flows externally, and most conspicuously of all in women, who discharge a greater amount than any other female animals. On this account it is always ver^' noticeable that the female is pale, and the blood-vessels are not prominent, and there is an obvious deficiency in physique as compared \\ith males.

Now it is impossible that any creature, should produce two seminal secretions at once, and as the secretion in females which answers to semen in males is the menstrual fluid, it obviously follows that the female does not contribute any semen to generation ; for if there were semen, there would be no menstrual fluid ; but as menstrual fluid is in fact formed, therefore there is no semen.

We have said why it is that the menstrual fluid as well as semen is a residue. In support of this, there are a number of facts concerning animals which may be adduced. (1) Fat animals produce less semen than lean ones, as Ave said before, and the reason is that fat is a residue just as semen is, i.e., it is blood that has been concocted, only not in the same way as semen. Hence it is not surprising that when the residue has been consumed to make fat the semen is deficient. Take a parallel from the bloodless animals : Cephalopods and Crustacea are in their finest condition at the breeding season. WTiy ? Because, being bloodless, they produce no fat ; hence, what in them corresponds to fat is at this period »secreted into the seminal residue. (2) Here is an indication that the female does not discharge semen of the same kind as the male, and that the offspring is not formed from a mixture of two semens, as some allege. Very often the female conceives although she has derived

no pleasure from the act of coitus ; and, on the contrary side, when the female derives as much pleasure as tile male, and they both keep the same pace, the female does not bear - unless there is a proper amount of menstrual Uquid (as it is called) present. Thus, the female does not bear (a) if the menstrual fluid is completely absent, (6) if it is present and the discharge of moisture is in progress (in most instances) ; but only (c) after the evacuation is over. The reason is that in one case (a) the female has no nourishment, no material, for the dynamis " supplied by the male in the semen to draw upon and so to cause the living creature to take shape from it ; in the other case (6) it is washed right away owing to the volume of the menstrual fluid. When, however, (c) the discharge is over and most of it has passed off, then what remains begins to take shape as a fetus. There are instances of women who conceive without the occurrence of menstrual discharge ; others conceive during its occurrence but not after it. The reasons are these. The former produce only just so much liquid as remains in fertile individuals ^ after the evacuation is over, and there is no surplus residue to be discharged externally ; in the latter, the mouth of the uterus closes up after the evacuation is over. Therefore, when there has been a plentiful discharge and yet the evacuation still continues, though not so copiously that the discharge of moisture carries the semen away with it, that is the time when if they have intercourse women can conceive again. There is nothing odd about the menstrual fluid's continuing to flow after conception has taken place ; indeed it actually recurs afterwards up to a point, but it is scanty and does not last throughout gestation. However, this is a morbid condition, and that is why it only occurs infrequently and in few subjects. It is what occurs generally that is most in accord with the course of Nature.

By now it is plain that the contribution which the female makes to generation is the matter used therein, that this is to be found in the substance constituting the menstrual fluid, and finally that the menstrual fluid is a residue.

There are some who think that the female con- XX tributes semen * during coition because women sometimes derive pleasure from it comparable to that of the male and also produce a fluid secretion. This fluid, however, is not seminal ; it is pecuUar to the part from which it comes in each several individual ; there is a discharge from the uterus, which though it happens in some women does not in others. Speaking generally, this happens in fair-skinned women '^ who are typically feminine, and not in dark women of a masculine appearance. Where it occurs, this discharge is sometimes on quite a diiFerent scale from the semen discharged by the male, and greatly exceeds it in bulk. Furthermore, differences of food cause a great difference in the amount of this discharge which is produced : e.g., some pungent foods cause a noticeable increase in the amount.

The pleasure which accompanies copulation is due to the fact that not only semen but also pneuma " is emitted : it is from this pneuma as it collects together that the emission of the semen results. This is plain in the ease of boys who cannot yet emit semen, though they are not far from the age for it, and in infertile men, because all of them derive pleasure from attrition. Indeed, men whose generative organs have been destroyed sometimes suffer from looseness of the bowels caused by residue which cannot be concocted and converted into semen being secreted into the intestine.

Further, a boy actually resembles a woman in physique, and a woman is as it were an infertile male ; the female, in fact, is female on account of inabiUt}'** of a sort, \\z., it lacks the power to concoct semen out of the final state of the nourishment (this is either blood, or its counterpart in bloodless animals) because of the coldness of its nature. Thus, just as lack of concoction produces in the bowels diarrhoea, so in the blood-vessels it produces discharges of blood of various sorts, and especially the menstrual discharge (which has to be classed as a discharge of blood, though it is a natural discharge, and the rest are morbid ones).

Hence, plainly, it is reasonable to hold that generation takes place from this process ; for, as we see, the menstrual fluid is semen, not indeed semen in a pure condition, but needing still to be acted upon. It is the same with fruit when it is forming. The nourishment is present right enough, even before it has been strained off, but it stands in need of being acted upon in order to purify it. That is why when the former is mixed with the semen, and when the latter is mixed %\ith pure nourishment," the one effects generation, and the other effects nutrition.

An indication that the female emits no semen is actually afforded by the fact that in intercourse the pleasure is produced in the same place as in the male by contact, yet this is not the place from which the liquid is emitted. Further, this discharge does not occur in all females, but only in those which are blooded, and not in all of them, but only in those whose uterus is not close by the diaphragm and which are not oviparous ; nor again in those which have an analogous substance instead of blood (they have another composition which is for them what blood is for the others). Dryness of the body is the cause why neither these animals nor the blooded ones I mentioned (viz., those whose uterus is low down and which are not oviparous) produce this evacuation ; their dr}-ness leaves over but little residue, only enough in fact for generation, not enough to be emitted externally. Take next the animals which are \-i\iparous but not previously oviparous : this means man, and those quadrupeds uhich bend their hind legs inwards. The menstrual discharge occurs in all of these ; though if they are deformed ^ in any respect main bulk of the body and not away from it, so that the angle of the bent joint points away from the body. " Inwards" thus has no reference to "knock knees." See I.A.

in their formation, as, e.g., the mule," the evacuation is not as ob^â– ious as it is in human beings. An exact account of this matter, as it concerns every sort of animal, is to be found in the Researches upon Animals.^ A larger amount of evacuation is produced by women than by any other animal, and a larger amount of semen in proportion to their size is emitted by men ; the reason being that the composition of the human body is fluid and warm, and that is just the sort of organism which of necessity produces the greatest amount of residue ; further, the human body does not possess the sort of parts to which the residue gets diverted, as other animals do : it has no great coat of hair all over the body,*^ and no secretions in the form of bones, horns and tusks.

Here is an indication that the semen resides in the menstrual discharge. As I said before, this residue is formed in males at the same time of Ufe as the menstrual discharge becomes noticeable in females ; which suggests that the places which are the receptacles of these residues also become differentiated at the same time in each sex ; and as the neighbouring ])laces in each sex become less firm in their consistency, the pubic hair grows up too. Just before these places receive their differentiation, they are swelled up by the pneuma : in males, this is clearer in regard to the testes, but it is also to be noticed in the breasts ; whereas in females it is clearer in the breasts : it is when the breasts have risen a couple of fingers' breadth that the menstrual discharge begins in most women.

Now in those li\-ing creatures where male and female are not separate, the semen (seed) is as it ' Or, in proportion to the size of the body.

were a fetation.** (By fetation I mean the primary mixture of male and female.) This explains incidentally why one body only is formed from one seed - e.g., one stalk from one grain of corn, just like one animal from one egg (double-yolked eggs of course count as two eggs). In those groups, however, where male and female are distinct, many animals may be formed from one semen, which suggests that the nature of semen in animals differs from that in plants.^ We have as a proof of this those animals which are able to produce more offspring than one at a time, where more than one are formed as the result of one act of coitus. This shows also that the semen is not drawn from the whole body ; because we cannot suppose (a) that at the moment of discharge • it contains a number of separate portions from one and the same part of the body ; nor (b) that these portions all enter the uterus together and separate themselves out when they have got there. No ; what happens is what one would expect to happen. The male provides the " form " and the " principle of the movement," ^ the female provides the body, in other words, the material." Compare the coagulation of milk. Here, the milk is the body, and the fig-juice or the rennet contains the principle which causes it to set.^ The semen of the male acts in the same way as it gets divided up into portions within the female. (Another part of the treatise^ will explain the Cause why in some cases it gets divided into many portions, in others into few, while in others it is not divided up at all.) But as this semen which gets divided up exhibits no difference in kind, all that

is required in order to produce numerous offspring is that there should be the right amount of it to suit the material available - neither so little that it fails to concoct it or even to set it, nor so much that it dries it up." If on the other hand this semen which causes the original setting remains single and undivided, then one single offspring only is formed from it.

The foreffoinor discussion will have made it clear that the female, though it does not contribute any semen to generation, yet contributes something, viz., the substance constituting the menstrual fluid (or the corresponding substance in bloodless animals). But the same is apparent if we consider the matter generally, from the theoretical standpoint. Thus : there must be that which generates, and that out of which it generates ; and even if these two be united in one, at any rate they must differ in kind,*^ and in that the logos "^ of each of them is distinct. In those animals in which these two faculties are separate, the body- - that is to say the physical nature - of the active partner and of the passive must be different. Thus, if the male is the active partner, the one which originates the movement, and the female qua female is the passive one, surely what the female contributes to the semen of the male ^\ill be not semen but material. And this is in fact what we find happening ; for the natural substance of the menstrual fluid is to be classed as " prime matter." * KtvTqaecas koI /lerajSoA^s." In its lowest phase, " prime matter" is that which, united with the prime contrarieties (hot, cold, solid, fluid), produces the " elements " Earth, Air, Fire, Water; but, as the term "prime " itself suggests, " matter" is altogether a relative conception, and in its highest phase matter is one and the same as "' form " {Met. 1045 b 18).

These then are the Unes upon which that subject XXI should be treated. And what we have said indicates generation. plainly at the same time how we are to answer the questions which we next have to conside?;, viz., how it is that the male makes its contribution to generation, and how the semen produced by the male is the cause of the offspring ; that is to say. Is the semen inside the offspring to start with, from the outset a part of the body which is formed, and minghng \vith the material pro\ided by the female ; or does the physical part of the semen have no share nor lot in the business, only the dynamis and movement contained in it ? " This, any^vay, is the active and efficient ingredient ; whereas the ingredient which gets set and given shape is the remnant " of the residue in the female animal. The second suggestion is clearly the right one, as is shown both by reasoning and by observed fact, (a) If we consider the matter on general grounds, we see that when some one thing is formed from the conjunction of an active partner \\ith a passive one, the active partner is not situated ^v'ithin the thing which is being formed ; and we may generalize this still further by substituting " moving " and " moved " for " active " and " passive." Now of course the female, qua female,*^ is passive, and the male, qua male, is active - it is that Avhence the principle of movement comes. Taking, then, the widest formulation of each of these two opposites, viz., regarding the male qua active and causing movement, and the female qua passive and being set in movement, we see that the one thing which is formed is formed /Vom them onlv in the sense in which a bedstead is formed from the carpenter and the wood, or a ball from the wax and the form. It is plain, then,

that there is no necessity for any substance to pass from the male ; and if any does pass, this does not mean tfiat the offspring is formed from it as from something situated \\-ithin itself during the process, but as from that which has imparted movement to it. or that which is its " form." The relationship is the same as that of the patient who has been healed to the medical art. (6) This piece of reasoning is entirely borne out by the facts. It explains why certain of those males which copulate with the females are observed to introduce no part at all into the female, but on the contrary the female introduces a part into the male. This occurs in certain insects.** In those cases where the male introduces some part, it is the semen which produces the effect inside the female ; but in the case of these insects, the same effect is produced by the heat and dynamis inside the (male) animal itself when the female inserts the part which receives the residue. And that is why animals of this sort take a long time over copulation, and once they have separated the young are soon produced : the copulation lasts until (the dynamis in the male) has " set " (the material in the female), just as the semen does ; but once they have separated they soon discharge the fetation, ** because the offspring they produce is imperfect ; all such creatures, in fact, produce larvae.

However, it is the beha\'iour of birds and the group of o\iparous fishes which provides us with our strongest proof (a) that the semen is not drawn from all the parts of the body, and (6) that the male does not emit anv part such as will remain situated within the fetus, but begets the young animal simply by means of the dynamis residing in the semen (just as we said happened with those insects where the female inserts a part into the male). Here is the evidence. Supposing a hen bird is in process of producing wind-eggs, and then that she is trodden by the cock while the egg is still completely yellow and has not yet started to whiten : the result is that the eggs are not wind-eggs but fertile ones. And supposing the hen has been trodden by another cock while the egg is still yellow," then the whole brood of chickens w^hen hatched out takes after the second cock. Some breeders who speciaUze in first-class strains act upon this, and change the cock for the second treading. The implication is (a) that the semen is not situated inside the egg and mixed up with it, and (b) that it is not dra\vn from the whole of the body of the male : if it were in this case, it would be draw'n from both males, so the offspring would have every part twice over. No ; the semen of the jnale acts otherwise ; in virtue of the dynamis which it contains it causes the material and nourishment in the female to take on a particular character ; and this can be done by that semen which is introduced at a later stage, working through heating and concoction, since the egg takes in nourishment so long as it is <jrowinff.

The same thing occurs in the generation of oviparous fishes. When the female fish has laid her eggs, the male sprinkles his milt over them ; the eggs which it touches become fertile, but the others are infertile, which seems to imply that the contribution which the male makes to the young has to do not with bulk but with specific character.

What has been said makes it clear that, in the case of animals which emit semen, the semen is not drawn from the whole of the body, and also that in generally

tion the contribution which the female makes to the embryos when they are being " set " and constituted is on different lines from that of the male ; in other words, the male contributes the principle of movement " and the female contributes the material. This is why (a) on the one hand the female does not generate on its own : it needs some source or principle to supply the material >rith movement and to determine its character (though in some (female) animals, as in birds, Nature can generate up to a point : the females of these species do actually " set " a fetation, but what they " set " is imperfect, xiz., what are kno^^^l as wind-eggs) ; (6) on the other hand, the formation XXII of the young does in fact take place in the female, whereas neither the male himself nor the female emits semen into the male, but they both deposit together what they have to contribute in the female - it is because that is where the material is out of which the creature that is being fashioned is made. And as regards this material, a good quantity of it must of necessity be available immediately, out of which the fetation is " set " and constituted in the first place, and after that fresh suppUes of it must be continually arri\'ing to make its growth possible. Hence, of necessity, it is in the female that parturition takes place. After all, the carpenter is close by his timber, and the potter close by his clay ; and to put it in general terms, the working or treatment of any material, and the ultimate movement ° which acts upon it, is in all cases close by the material, e.g., the location of the activity of house-building is in the houses which are being built. These instances may help us to understand how the male makes its contribution to generation ; for not every male emits

semen, and in the case of those which do, this semen is not a part of the fetation as it develops. In the same way, nothing passes from the carpenter into the pieces of timber, which are his material, and there is no part of the art of carpentrj' present in the object which is being fashioned : it is the shape and the form which pass from the carpenter, and they come into being by means of the movement in the material. It is his soul, wherein is the " form," and his knowledge, which cause his hands (or some other part of his body) to move in a particular way (different ways for different products, and always the same way for any one product) ; his hands move his tools and his tools move the material." In a similar way to this, Nature acting in the male of semen-emitting animals uses the semen as a tool, as something that has movement in actuality ; just as when objects are being produced by any art the tools are in movement, because the movement which belongs to the art is, in a way, situated in them. Males, then, that emit semen contribute to generation in the manner described. Those which emit no semen, males into which the female inserts one of its parts, may be compared to a craftsman who has his material brought to him. Males of this sort are so weak that Nature is unable to accomplish anything at all through intermediaries : indeed, their movements are only just strong enough when Nature herself sits watching over the business ; the result is that here Nature resembles a modeller in clay rather than a carpenter ; she does not rely upon contact exerted at second hand when fashioning the object which is being given shape, but uses the parts of her o^\â– n very self to handle it.

In all animals which can' move about, male and female are separate ; one animal is male and another female, though they are identical in species, just as men and women are both human beings, and stallion and mare are both horses. In plants, however, these faculties are mingled together ; the female is not separate from the male ; and that is why they generate out of themselves, and produce not semen but a fetation - what we call their '" seeds." Empedocles puts this well in his poem, when he says " : So the great trees lay eggs ; the olives first . . ., because just as the egg is a fetation from part of which ^ the creature is formed while the remainder is nourishment, so from part of the seed is formed the growing plant, while the remainder is nourishment for the shoot and the first root. And in a sort of way the same happens even in those animals where male and female are separate ; for when they have need to generate they cease to be separate and are united as they are in plants : their nature desires that they should become one. And this is plain to see when they are uniting and copulating [that one animal is produced out of the two of them].

The natural practice of those animals which emit no semen is to remain united for a long time, until <the male) has " set "the fetation : those Insects wliich copulate are an example of this. Other animals, however, remain united until the male has introduced from those " parts " '^ of himself which he inserts one which ^\-ill " set " the fetation but will take a longer time to do so : the blooded animals illustrate this. The former sort remain in copulation for a fair part of a day ; whereas semen takes several days to " set " fetations, and when the creatures have emitted this they free themselves. Indeed, animals seem to be just like divided plants : as though you were to pull a plant to pieces when it was bearing its seed and separate it into the male and female present in it.

In all her workmanship herein Nature acts in every particular as reason would expect. A plant, in its essence, has no function or activity to perform other than the production of its seed * ; and since this is produced as the result of the union of male with female. Nature has mixed the two and placed them together, so that in plants male and female are not separate. Plants, however, have been dealt \nth in another treatise ; here we are concerned with animals, and generation is not the only function which an animal has - that is a function common to all things living. All animals have, in addition, some measure of knowledge of a sort (some have more, some less, some very little indeed), because they have senseperception,* and sense-perception is, of course, a sort of knowledge. The value we attach to this knowledge varies greatly according as we judge it by the standard of human intelhgence or the class of hfeless objects. Compared with the intelligence possessed by man, it seems as nothing to possess the two senses of touch and taste only ; but compareH mth entire absence of sensibility it seems a very fine thing indeed. We should much prefer to have even this part of knowledge to a state of death and non-existence. Now it is by sense-perception that animals differ from the creatures which are merely alive ; since, however, if it be an animal, its attributes must of necessity include that of being alive, when the time comes for it to accompUsh the function proper to that which is aUve," then it copulates and unites and becomes as it were a plant, just as we have said.

The Testacea stand midway between animals and plants and so, as being in both groups, perform the function of neither : as plants, they do not have male and female and so they do not generate by pairing ; as animals they bear no fruit externally Uke that borne by plants ; but they take shape and are generated out of a certain earthv and fluid coagulation. The manner of generation of these creatures, however, mxist be described later.* living things must possess, is also to yewrjriKov irepov olov avTo (735 a 17, 18). » InBk. Ill, ch. 11.

Book II

I HAVE already said that the male and the female are I "principles" of generation, and I have also said ^J^'g'^^j what is their dynamis ° and the logos ^ of their essence. '^ As for the reason why one comes to be formed, and is, male, and another female, (o). in so far as this results from necessity,^ i.e., from the proximate motive cause and from what sort of matter, our argument as it proceeds must endeavour to explain ; (6) in so far as this occurs on account of what is better, i.e., on account of the final cause (the Cause " for the sake of which "), the principle is derived from the upper cosmos.* What I mean is this. Of the things which are, some are eternal and divine, others admit alike of being and not-being, and the beautiful and the divine acts always, in virtue of its own nature, as a cause which produces that which is better in the things which admit of it -^ ; while that which is not eternal admits of being (and notbeing), and of acquiring a share both in the better and in the worse ; also. Soul is better than body, and a tiling which has Soul in it is better than one which has not, in virtue of that Soul ; and being is better than not-being, and U\ing than not li\ing. These are the causes on account of which generation of animals takes place," because since the nature of a class of this sort is unable to be eternal, that which comes into being is eternal in the manner that is open to it. Now it is impossible for it to be so numerically, since the " being " of things is to be found in the particular, and if it really were so, then it would be eternal ** ; it is, however, open to it to be so specifically. That is why there is alwavs a class of men, of animals, of plants ; and since the principle of these is " the male " and " the female," it will surely be for the sake of generation that " the male " and " the female " are present in the individuals which are male and female. And as the form). Hence, in the present sentence roioOrov means dpidfiw tuSiov ; and the sense of the statement is that if an animal really were dpidful> di'Siov, its oiaia would be dt'Scos-, i.e., a(f>6apTos ; in other words, it would no longer be a <f>dapr6v or a yiyvd/xevoi'. The translation might be expanded as follows to bring out the meaning : " Now it is impossible for it to be so mimerically, since the " being " of things is in the particular <:i.e., in the individual concrete object consisting of matter and form ; and obviously no such particular <f>6apT6v - animal or plant - can be numerically eternab ; and if it really were so, then it would be eternal <in the full and proper sense of the term, viz., it would be d<f>dapTov, and no longer a yiyvofioov at all> ; it is, however, open to it to be eternal specifically."' It is useful to note that at Met. 999 b 33 Aristotle states that there is no difference between the terms dpddyiu) €v and Kad' CKaarov (to dpidfuu ev rj to KaO' eKoorov Xeyeiv 8ia<f€p€i ovBev). - See further, App. A proximate motive cause," to which belong the logos and the Form, is better and more divine in its nature than the Matter,** it is better also that the superior one should be separate from the inferior one. That is why wherever possible and so far as possible the male is separate from the female, since it is something better and more divine in that it is the principle of movement '^ for generated things, while the female serves as their matter. The male, however, comes together with the female and mingles \\ith it for the business of generation, because this is something that concerns both of them.

Thus things are alive in \irtue of having in them a share of the male and of the female, and that is why even plants have life. The class of animals, however, is <what it is) in virtue of its power of sense-perception.^ In practically all animals which can move about the male and the female are found separate, and the causes are the ones which have been stated ; and, as was said,^ some of them emit semen during copulation, some do not. The reason for this is that the higher animals are more self-sufficient in thennature, and so are large in size : this cannot be so ^^'ithout heat of Soul, since of necessity the larger a thing is, the greater the power required to move it, and heat acts as a motive power. Hence, if we take a general view, we may say that blooded animals are larger than bloodless, and mobile ones larger than stationary ; and they are the ones which emit semen on account of their heat and their size.] We have now stated the Cause why each of the two, male and female, is.

Some animals bring their young to perfection, and The various bring forth externally a creature similar to them- generation. selves - e.g., those which are externally \iviparous ; others produce something which is unarticulated and has not yet assumed its proper shape. In the latter class those which are blooded lay eggs, those which are bloodless produce (either eggs or) larvae.** The difference between an eg^ and a larva is this : an cg^g is something from part of which the new creature is formed, while the remainder is nourishment for it ; whereas in the case of the larva, the jvhole of it is used to form the whole of the offspring. Of the animals which produce externally a perfected creature similar to themselves, i.e., the \ ivipara, some are internally viviparous from the outset (as man, horse, ox ; and of sea-creatures, the dolphin and the other animals of that sort), others are internally oviparous at the first stage, and thereafter are externally viviparous (as what are called Selachia). Of oviparous animals, some lay their eggs in a perfected state (as birds, oviparous quadrupeds and footless animals, e.g., Hzards and tortoises, and the great majority of the serpents '")- eggs which on6e they are laid do not grow any more ; others lay their eggs in an imper ment, and the utilization of tissue-disintegration products in metamorphosis. The embryo feeds upon its yolk, but the pupa feeds upon itself.

feet state, as the Fishes, and the Crustacea and the Cephalopods as they are called, whose eggs do grow in size after they are laid.^ All animals that are viviparous [or o\'iparous] are blooded, and animals that are blooded are either \'i\iparous or o\'iparous, apart from those which are completely infertile. Of bloodless animals. Insects produce a larva ; this holds good both for those which are formed as a result of copulation and those which themselves copulate. ** (A note of explanation : there are certain Insects which, although formed by spontaneous generation, nevertheless are male and female, and as a result of their copulation something is formed, though it is imperfect : the cause of this has already been stated elsewhere.) Actually there is a good deal of overlapping be- ciassificatween the various classes. Bipeds are not all \-i\d- a'^^ais. parous (birds are o\'iparous) nor all oviparous (man is viviparous) ; quadrupeds are not all oviparous (the horse and ox and heaps of others are \i\iparous), nor all viviparous (lizards and crocodiles and many others are oviparous). Nor does the difference lie even in having or not having feet : some footless animals are viviparous (as vipers, and the Selachia), some are oviparous (as the class of fishes, and the rest of the serpents) ; and of the footed animals many are oviparous, many viviparous {e.g., the quadrupeds already mentioned). There are footed animals which are internally viviparous (as man), and footless ones also (as the whale and dolphin). So we find no means here for making a division " : the cause of this difference and my note there), as used, though for a different purpose, by Plato in Sophist and PoUticus {e.g., the division into to ne^ov and to vevarucov at Sophist 220 a).

does not lie in any of the organs of locomotion. No ; those animals are W^iparous which are more perfect in their nature, which partake of a purer " principle " ; in other words, no aninial is internally vixiparous unless it draws in breath - respires. The more perfect animals are those which are by their nature hotter and more fluid and are not earthy. (The test of natural heat is the presence of the lung, provided it has blood in it. Speaking generally, animals which have a lung are hotter than those that have none, and of the former those are hotter w'hose lung is not spongv nor compact nor poorly supplied M"ith blood, but well supplied with blood and soft.) And since an actual animal is something perfect whereas larvae and eggs are something imperfect, Nature's rule is that the perfect offspring shall be produced by the more perfect sort of parent. Those animals which are hotter (as their having a lung indicates), though of a more solid" consistency, or are colder but more fluid, either (o) are oviparous and lay a perfect egg, or (b) first lay an egg and then are viviparous internally. Thus, birds and the animals with horny scales, on account of their heat, produce something perfect, but on account of their solidity it is an egg only  ; the Selachia are less hot than these are, but more fluid ; hence they share in the characteristics of both - they are oviparous because they are cold creatures, and internally viviparous because they are fluid (the reason being that fluid matter is conducive to life, whereas solid matter and the living organism are at opposite poles) ; and as they have neither feathers nor horny plates nor scales, which are signs of a constitution that tends to be solid and earthy, the egg which they produce is

a soft one : the earthy substance does not come to the surface in the egg any more than it does in the creature wliich lays it. And that is why they lay their eggs internally : if the eggs emerged they would be destroyed through lack of protection.

Animals that tend to be cold and solid lay eggs, it is true, but their egg is imperfect, and it has a hard covering (a) because the animals themselves are earthy and (6) because it is in an imperfect state when laid, and the shelly exterior serves as a protection to keep it safe. Thus fishes, being scaly, and Crustacea, being earthy, produce eggs with a hard covering ; while the Cephalopods, which also lay imperfect eggs, keep them safe by a method in accordance with the sticky nature of their own bodies ; they exude a large amount of sticky substance over the fetation. Insects all produce larvae. Now all Insects are bloodless, and that actually is why they are externally larva-producing. But it is not true that all bloodless animals are larva-producing without qualification, because there is overlapping as between the larva-producing animals and those that produce imperfect eggs (e.g., the scaly fishes, the Crustacea and the Cephalopods), since the eggs of the latter are larva-like, in that they grow bigger after they have been laid externally, while the larvae of the former, as they develop, become egg-like : we shall explain later how this happens." We should notice how well Nature brings generation about in its several forms : they are arranged in a regular series, thus : (1) The more perfect and hotter of the animals produce their young in a perfect state so far as their quality is concerned (no animal brings forth young that are perfect in size, because

they all grow in size after they have been produced), and these young which they generate are hving creatures inside them from the outset. (2) The second class do not generate perfect animals within themselves from the outset : although they are viviparous, they lay eggs first of all ; externally however they are viviparous. (3) Others produce not a perfect animal, but an egg, which is perfect. (4) Those whose constitution is still colder than this produce an egg, but it is not a perfect one : it reaches its perfection outside the parent. Examples are the scaly fishes, the Crustacea and the Cephalopods. (5) The fifth class of creatures, which are the coldest of all, do not even lay an egg directly themselves, but the formation of their egg takes place outside the parent, as has been said." What happens is that Insects first produce a larva, then the larva develops till it becomes egg-hke (what is called the chrysalis is really equivalent to an egg ^) ; then out of this an animal is formed, and it is not until this third stage in its series of changes that it reaches the end and perfection of its generation.

There are, then, some animals which are not formed from semen, as I have in fact said already. All blooded ones, however, are formed from semen, so many as are formed as the result of copulation, that is to say, the male emits semen into the female, and upon the entry of the semen the young animals are " set " and constituted and assume their proper shape ; with the xiviparous animals this stage takes place within the parent, with others in the eggs [and seeds and other such secretions].

And on this subject we are confronted by no small puzzle." How, we ask, is any plant formed out of the embryo seed, or any animal out of the semen ? That which is formed by means of a process must of necessity be formed (a) out of something (b) by something (c) into something. " Out of something." This of course is the material or matter. Some animals have thenprimary matter ^ within themselves, having derived it from the female parent, e.g., those animals which are produced not viWparously but out of larvae or eggs. Others derive it from the mother for a considerable time by being suckled. These are the animals which are produced \iviparously not externally only but also internally.*^ So then, that " out of which " the parts are formed is material of this sort. The problem now before us however is not Out of what, but. By what, are they formed ? Either something external fashions them, or else something present in the semen or seminal fluid ; and this is either some part of Soul, or Soul, or something which possesses Soul. Now it would appear unreasonable to suppose that anything external fashions all the indi\idiial parts, whether they be the viscera or any others, because unless it is in contact ** it cannot set up any movement, and unless it sets up a movement no effect can be produced upon anything by it. Hence it follows that there must be something already present inside the fetation itself, which is either a part of it or separate from it.

To suppose it is some other thing, and separate from it, is not reasonable. If it were, the question arises : When the animal's generation is completed, does this something disappear, or does it remain ^\â– ithin the animal ? We cannot detect any such thing, something which is in the plant or the animal and yet is no part of the organism as a whole. And again, to say that it fashions all the parts or some parts of the organism and then disappears is ridiculous. If it fashions only some of the parts, what will fashion the rest ? Supposing it fashions the heart, and then disappears, and the heart fashions some other part : to be consistent we must say that either all the parts disappear or all the parts remain." It must, then, persist. And therefore it must be a part of the whole, existing in the semen from the outset. And if it is true that there is no part of the Soul Avhich is not in some part of the body,^ then it must also be a part which contains Soul from the outset.

How, then, are the other parts formed ? Either they are all formed simultaneously - heart, lung, Uver, eye, and the rest of them - or successively, as we read in the poems ascribed to Orpheus, where he says that the process by which an animal is formed resembles the plaiting of a net. As for simultaneous formation of the parts, our senses tell us plainly that this does not happen : some of the parts are clearly to be seen present in the embryo while others are not. And our failure to see them is not because they are too small ; this is certain, because although the lung is larger in size than the heart it makes its appearance later in the original process of formation. Since one part, then, comes earlier and another later, is it the case that A fashions B and that it is there on account of B which is next to it, or is it rather the case that B is formed after A ? I mean, for instance, not that the heart, once it is formed, fashions the liver, and then the hver fashions something else ; but that the one is formed after the other [just as a man is formed after a child], not by it. The reason of this is that, so far as the things formed by nature or by human art are concerned, the formation of that which is potentially is brought about by that which is in actuality ; so that the Form, or conformation, of B would have to be contained in A,' e.g., the Form of the liver would have to be in the heart - -which is absurd. And there are other ways too in which the theory is absurd and fondly invented. But besides, for any part of the animal or plant to be present from the outset ready foi-med within the semen or seed, whether it has the power to fashion the other parts or not - even this is impossible if everything is formed out of semen or seed ; because it is plain that it was formed by that which fashioned the semen if it is present within the semen from the outset ; but semen must be formed before (any part), and that is the business of the parent. Therefore no part can be present within the semen. Therefore it does not contain in itself that which fashions the parts. And yet this cannot be external to the semen either " : and it must be either external to it or inside it.

Well, we must endeavour to solve this difficulty. Maybe there is some statement of ours, made without qualification, which ought to be qualified : e.g., if we ask, in irhat sense exactly is it impossible for the parts to be formed by something external ? we see that in one sense it is possible, though in another it is not.

Now it makes no difference whether we say " the semen " or " that from which the semen comes," in so far as the semen has within itself the movement which the generator set going. " And it is possible that A should move B, and B move C, and that the process should be like that of the " miraculous " automatic puppets ^ : the parts of these automatons, even while at rest, have in them somehow or other a potentiality, and when some external agency sets the first part in movement, then immediately the adjacent part comes to be "^ in actuality. The cases then are parallel : just as ^^ith the automaton (1) in one way it is the external agency which is causing the thing's movement - \iz., not by being in contact with it anywhere now, but by having at one time been in contact \vith it, so too that from which the semen originally came, or that which fashioned the semen, (causes the embrj-o's movement) ** - \\z., not by being in contact with it still, but by having once been in contact with it at some point ; (2) in another way, it is the movement resident â– \vithin (which causes it to move), just as the acti\ity of building causes the house to get built.* It is clear by now that there is something which fashions the parts of the embryo, but that this agent is not by way of being a definite indi\idual thing,' nor is it present in the semen as something already perfected to begin with.

To answer the question. How exactly is each of the parts formed ? we must take first of all as our starting-point this principle. Whatever is formed either by Nature or by human Art, say X, is formed bv something which is X in actuality out of something which is X potentially.'^ Now semen, and the movement and principle ** which it contains, are such that, as the movement ceases '^ each one of the parts gets formed and acquires Soul. (I add " acquires Soul," because there is no such thing as face, or flesh either, without Soul in it ; and though they are still said to be " face " and " flesh " after they are dead, these terms will be names merely (" homonyms "),'* just as if the things were to turn into stone or wooden ones.) And the formation of the " uniform " parts* and of the instrumental parts goes on simultaneously. And as in speaking of an axe or any other instrument, we should not say that it was made solely by fire, so we should not say this about a foot or a hand (in the embryo), nor, similarly, of flesh either, because this too is an instrument with a function to perform. As for hardness, softness, toughness, brittleness and the rest of such qualities Avhich belong to the parts that have Soul in them - - heat and cold may very well produce these, but they certainly do not produce the logos ^ in direct consequence of which one thing is flesh and another bone ; this is done by the movement which derives from the generating parent, who is in actuality what the material out of which the offspring is formed is potentially. Exactly the same happens with things formed by the processes of the arts. Heat and cold soften and harden the iron, but they do not produce the sword ; this is done by the movement of the instruments employed, which contains the logos of the Art ; since the Art is both the principle " and Form of the thing which is produced ; but it is located elsewhere than in that thing, whereas Nature's movement is located in the thing itself which is produced, and it is derived from another natural organism which possesses the Form in actuality. As for the question whether the semen possesses Soul or not, the same argument * holds as for the parts of the body, viz.. (a) no Soul will be present elsewhere than in that of which it is the Soul ; (6) no part of the body \\i\\ be such in more than name ^ unless it has some Soul in it (e.g., the eye of a dead person). Hence it is clear both that semen possesses Soul, and that it is Soul, potentially. And there are varying degrees in which it may be potentially that which it is capable of being - it may be nearer to it or further removed from it (just as a sleeping geometer is at a further remove than one who is awake, and a waking one than one who is busy at his studies). So ** then, the cause of this process of formation is not any part of the body, but the external agent which first set the movement going - for of course nothing generates itself,* though as soon as it has been formed a thing makes itself grow.^ That is why one part is formed first, not all the parts simultaneously. And the part which must of necessity be formed first is the one which possesses the principle of growth : be they plants or animals, this, the nutritive, faculty is present in all of them alike (this also is the faculty

of generating another creature like itself, since this is a function which belongs to every animal and plant that is perfect in its nature)." The reason why this must of necessity be so is that once a thing has been formed, it must of necessity grow. And though it was generated by another thing bearing the same name ^ {e.g., a man is generated by a man), it grows by means of itself. So then, since it makes itself grow, it is something '^ : and if indeed it is some one thing, and if it is this first of all, then this must of necessity be formed first. Thus, if the heart is formed first in certain animals (or the part analogous to the heart, in those animals which have no heart), we may suppose that it is the heart (or its analogue) which supplies the principle. The queries raised earher have now been dealt with. We have answered the question. What is the cause (in the sense of principle) of the generation of each individual - what is that which first sets it in movement and fashions it ? A puzzle which may now be propounded is, WTiat II is the nature of Semen r Semen when it leaves the Semen, animal is thick and white, but when it cools it becomes fluid Uke water and is of the colour of water. This nutritive Soul, viz., the heart- And that is why the heart is the first thing to be formed." Cf. 740 a 21 (where there is no need to alter the text).

The meaning of this passage seems to be that the semen, though it must have (and be) Soul, can have (and be) Soul potentially only ; and the realizing of this potentiality, which is the process of formation or generation (of which the parent is the agent), goes on gradually - thus, the first part of the Soul to be formed, generated, or realized, is the part which produces growth (to dpeTrriKov), and with it the part of the body in which that part of the Soul resides, viz., the heart. (See 763 b 25, n.)

may seem strange, because water is not thickened by heat, vet semen is thick when it leaves the inside of the animal, which is hot, and becomes fluid when it cools. Moreover, watery substances freeze, but semen does not freeze when exposed to frost in the open air ; it becomes fluid, which suggests that it was heat that thickened it. And yet it is not very probable that it is thickened by heat, because it is substances that contain a large proportion of earth which " set " and thicken when boiled - milk, for example ; hence it ought to soUdify when it cools, but in fact it does not solidify at all ; the whole of it becomes fluid like water. This then is the puzzle. Suppose that semen is water. Water is never observed to be thickened by heat ; whereas semen is both thick and hot, and the body it comes from is hot. Or suppose it consists of earth, or is a mixture of earth and water. In that case the whole of it ought not to become fluid and turn to water. Perhaps then after all we have not distinguished all the cases that occur. Other fluids thicken beside those which are composed of water and earthy matter, viz., those composed of water and pneuma,'^ for instance, foam, which becomes thicker, and white ; and the smaller and more microscopic the bubbles are, the whiter and more compact is the appearance of the bulk. Oil behaves in the same way ; it thickens when it gets mixed with pneuma ; and that is why (oil) when it becomes whiter is thickening, since the watery substance in it is separated out from

it by the heat and becomes pneuma. Lead ore," too, when it gets mixed with water and oil, increases its bulk, and whereas it was fluid and black it becomes tliick and coherent and white. The reason is that pjieuma gets mixed in with it, and this produces the increase of bulk and lets the whiteness show through, precisely as it does with foam, and also with snow (because snow too is a foam). Even water itself when it gets mi;xed with oil becomes thick and white, the reason being that some pneuma is left behind in it owing to the friction of mixing, and also that oil itself contains a good deal of pneuma - for of course shininess is a quaUty of pneuma, not of earth or water. And that too is why oil floats on the surface of water ; air is contained in it, as though in a vessel, and this air buoys it up and causes it to float ; thus the air is the cause of its lightness. Further, in time of cold and frost, oil thickens, but does not freeze. Its failure to freeze is due to its heat - because the air is hot and is impervious to frost. But it thickens because the air is coagulated and compressed [as] by the cold. These reasons explain the behaviour of semen as well. It is coherent and white when it comes forth from within, because it contains a good deal of hot pneuma owing to the internal heat of the animal.

Later, when it has lost its heat by evaporation and the air has cooled, it becomes fluid and dark, because the water and whatever tiny quantity of earthy matter it may contain stay behind in the semen as it soUdifies, just as happens ^^•ith phlegma.^ Semen, then, is a compound of pneuma and water (pneuma being hot air), and that is why it is fluid in its nature ; it is made of water. Ktesias of Knidos ^ is obviously mistaken in his statement about the semen of elephants : he says that it gets so hard when it sohdifies that it becomes Uke amber. It does not. It is, of course, true that one semen must of necessity be earthier than another, and the earthiest v^ill be in those animals which, for their bodily bulk, contain a large amount of earthy matter ; but semen is thick and white because there is pneuma mixed with it. WTiat is more, it is white in all cases. Herodotus '^ is incorrect when he says that the semen of Ethiopians is black, as though everything about a person with a black skin were bound to be black - and this too in spite of their teeth being white, as he could see for himself. The cause of the whiteness of semen is that it is foam,<* and foam is white, the whitest being that

which consists of the tiniest particles, so small that each Lndi\'idual bubble cannot be detected by the eye. An instance of such a foam, mentioned earlier, is that produced by the mechanical mixing of water and oil.

That the natural substance of semen is foam-like was, so it seems, not unknown even in early days ; at any rate, the goddess who is supreme in matters of sexual intercourse was called after foam." We have now given the reason which solves the puzzle that was stated. And this also shows, incidentally, why semen does not freeze : it is because air is imper\'ious to frost.

The next puzzle to be stated and solved is this. Ill Take the case of those groups of animals in which g*â„¢,®" *"^ semen is emitted into the female by the male. Su|>posing it is true that the semen which is so introduced is not an ingredient in the fetation ^ which is formed, but performs its function simply by means of the dynamis '^ which it contains. Verj- well ; if so, what becomes of the physical part of it ? First of all we shall have to decide (a) whether that which takes shape within the female does or does not incorporate into itself any portion of that which was introduced (from the male) ; and (6) whether Soul - and it is in ^•irtue of Soul that an animal has the name of " animal " : it is in fact in virtue of the sentient part ** of Soul that it is an animal ^ - whether Soul is or is not in the semen and in the fetation to begin \^ith, and if so where it comes from. No one, of course, would maintain that the fetation is quite without Soul, completely devoid of life in every sense,

for the semens and the fetations of animals are just as much alive as plants are, and up to a point they are fertile.^ Thus it is clear that they possess nutritive Soul (vide my remarks on Soul in another treatise * for an explanation of why nutritive Soul must of necessity be acquired first). It is while they develop that they acquire sentient Soul as well, in virtue of which an animal is an animal - I say, " while they develop," for it is not the fact that when an animal is formed at that same moment a human being, or a horse, or any other particular sort of animal is formed, because the end or completion is formed last of all, and that which is peculiar to each thing is the end of its process of formation.'^ That is why it is a very great puzzle to answer another question, concerning Reason. At what moment, and in what manner, do those creatures which have this principle of Reason acquire their share in it, and where does it come from ? This is a very difficult problem which we must endeavour to solve, so far as it may be solved, to the best of our power.

As regards nutritive Soul, then, it is clear that we must posit that semens and fetations which are not separated (from the parent) possess it potentially, though not in actuality - i.e., not until they begin to draw the nourishment to themselves and perform the function of nutritive Soul, as fetations which get separated* (from the parent) do ; for to begin with it seems that all things of this sort live the life of a Vher Entxoicklungsgesctiirhte der Thiere, Beohachtung und Reflexwn (1828), i. 2i4, Scholion V (1) Dass das Gemeinsame einer grossern Thiergruppe sich friiher im Embryo bildet, als das Besondere. et seqq.)

    • The solution begins by resuming the argument from 736 a 32-34. • e.g., seeds of plants.


736 b

ARISTOTLE (f)VTOv ^iov. inofxevcos 8e SrjXov otl /cat Trepl rrjs atadrjTLKTjs XcKreov ^V)(fjs kol nepl rrjs vorjrtKfjs 15 TTaaas yap dvayKalov Svvdfjiei rrpoTepov €)(€lv r) eve py eia. dvayKalov Be tJtol [x-rj ovaas vpoTepov eyyiveadaL Trdaas, rj irdaas Trpov-nap^^^ovaa? , ■^ rds jxev rds 8e /iij, Kal eyyiveadai 7) ev rfj vXr) [mt] eiaeXdovaas ev rep rov dppevos aTTepfjuart, •^ evravda puev eKeWev eXOovaas, ev Se ro) dppevL r^ 20 dvpadev eyyivofievag drrdaas r^ pLTjSejJiLav r) rds fxev rds Be pLTj. OTL fiev roivvv ovx olov re Trdaas irpovTrdp^eiv, (fyavepov eartv e/c tcDv tolovtcov. oaiov ydp iariv dp^o^v^ rj eve py eia acoiiariKi], SrjXov on ravras dvev acoixaros dhvvarov VTrdpxeiv, olov ^a- | Si^etv dvev ttoScov ware Kal dvpadev elaievai " 25 aBvvaTOV ovre ydp avrds KaO^ avrds elaievai \ olov re dxojpiarovs ovaag, ovr^ ev aiop^ari elaievai'

irpd^ecDv coniecerunt A.-W.

" This elaborate scheme of possibilities is not really so overwhelming as it looks, though the argument would have been more lucid if Aristotle had explicitly named the several sorts of Soul involved. It will be seen, however, that of the first three possibilities, the last, (c), is the operative one ; in fact, it is nutritive Soul which the material of the female (more specifically, the fetation) possesses (see 736 a 32 ff., 737 a 23 ff ) ; thus it remains for the other two, sentient and rational Souls, to be feiipplied by the male (Aristotle explains in ch. 5 below that the reason why a fetation can grow yet is unable to develop fully into an animal is that it lacks sentient Soul, which only the male can supplj^). Hence in the second series of possibilities it is again the last one, (c), which is the operative one : sentient Soul is present inside the male (i.e., the semen), and it remains that rational Soul comes into being inside the male (i.e., the semen) from some outside source, for it alone is not afifected by the two considerations which preclude the entry from outside of the other parts of Soul, whose activity 168




plant. And it is clear we should follow a similar line also in our statements about sentient Soul and rational Soul, since a thing must of necessity possess every one of the sorts of Soul potejitially before it possesses them in actuality. And necessity requires either (a) that none of them exists previously, and that they all come to be formed in <the fetation) ; or (b) that they are all there beforehand ; or (c) that some of them are there and some are not ; and further, that they come to be formed in the material supplied by the female either (a) without having entered in the semen of the male or (6) after having so entered - that is, ha\"ing come from the male, and if so, then that either (a) all of them or (6) none of them or (c) some of them come to be formed within the male from some outside source." Now the following considerations plainly show that they cannot all be present beforehand. Clearly, those principles whose activity is physical cannot be present mthout a physical body - there can, for example, be no walking without feet * ; and this also rules out the possibiUty of their entering from out side, since it is impossible either that they enter by themselves, because they are inseparable (from a physical body), or that they enter by transmission in some body, because the is essentially physical (see also below, T37 a 9 f.). Thus, sentient Soul, and a fortiori rational Soul, are supplied by the male, through the semen, to the material provided by the female. Aristotle does not, however, give any fuller solution than this to his own "very difficult puzzle" how and when rational Soul, which is thus supplied in a potential state by the male, is actualized in the oflFspring.

•" Aristotle takes the " locomotive Soul," the highest of the " parts " or " faculties " of Soul apart from " rational Soul," and shows that this cannot enter by itself ; a fortiori therefore none of the lower " parts " can do so.


ARISTOTLE TO yap OTTepixa Trepirrcoixa pbera^aXXovarjs rrjg Tpocfjrjg eariv. AeiVerat Si^^ rov vovv piovov dvpaOev eTTeiatevai /cat deXov elvai pbovov ovOkv yap avTov TTJ ivepyeia Kocvcovel (JiopiarLKrj ivepy eta. 30 Ildarjs ptev ovv ipvxrjs hvvapLLS irepov aayp-aros €OiK€ KeKoivojvrjKevai /cat deiorepov roJv KaXovpievcov aroix^^^v' (hs 8e Sta^epoyat npLLor'qri at ijiv^oX /cat drt/ita aXX-qXcxiv, ovrco /cat rj roLaurrj Sta^epet (fjvacs- Trdvrojv piev yap iv rqj airippiari ivvTTapxit,, OTTep TTOtel yovipia etvat to. airippiara, 35 TO KaXovpuevov deppuov. tovto 8' ov TTvp ouSe Toiavrr] Svvapitg ecrrtv, aAAa to ipbTrepiXapL^avopLevov iv TO) (jTreppLaTL /cat iv tw a.(f)pa)Sei TTvevpta /cat T) iv Tw TTvevpiaTL (/)vat,s, dvdXoyov ovaa tco 737 a Tcbv daTpoiv crrotp^e ta>. Sto rrvp piev ouOev yevva i,ci)ov, ovde (f>aiV€Tai avviaTdpievov iv' TTvpovpbivois ovT iv vypols ovT iv ^rjpol^ ovOiv rj Se tov rjXcov deppbOTTj^ /cat rj Ttov t,ipojv ov pLovov rj Sto. tov ^ 8rj Platt, Zeller, Btf. : Se vulg. * eV P : om. vulg.

" i.e., it is not a body possessing the parts necessary in order to give eifect to the activities involved, such as legs for walking. Cf. P. A. 641 b 31 yeveaLS /u.ev yap to anipixa, ovata 8e TO re'Ao?.

  • Cf. De anlma 413 a 4 ff.

« Cf. 762 a 20. '^ See 736 a 13 ff.

  • This is the so-called " fifth element," {i.e., over and above the four " elements " foimd in the sublunary regions, viz., earth, air, fire, and water), though Aristotle's own name for it is " the first of the elements " (to npcoTov tu>v oTotxeiojv, De caelo 298 b 6, to Trpayrov awfia, 270 b 21), owing to its pre-eminent qualities. The arguments for its existence will be found in De caelo, Bk. I ; it is ungenerated, indestruct170


semen is a residue of the nourishment that is undergoing change." It remains, then, that Reason alone enters in, as an additional factor, from outside, and that it alone is divine, because physical activity has nothing whatever to do with the activity of Reason.* Now so far as we can see, the faculty of Soul of every kind has to do with some physical substance which is different from the so-called " elements " and more divine than they are ; and as the varieties of Soul differ from one another in the scale of value, so do the various substances concerned with them differ in their nature. In all cases the semen contains within itself that which causes it to be fertile - what is known as " hot " substance,*^ which is not fire nor any similar substance, but the pneuma which is enclosed within the semen or foam-like stuff,'* and the natural substance which is in the pneuma ; and this substance is analogous to the element which belongs to the stars.® That is why fire does not generate any animal,^ and we find no animal taking shape either in fluid or solid substances while they are under the influence of fire ; whereas the heat of the sun ' does effect generation, and so does the heat of animals, ible, and divine (269 a 31 flF., 270 a \2 fF., 270 b 10 ff.)- Aristotle claims that it was va^ely recognized by the ancients, as is suggested by the name (aither) they gave to " the uppermost place " (270 b 16 if.) : d-rro rov 9eiv del tov dlSiov â– )(p6vov Be/xevoi T^v iirojwfjiiav avTu>. {Cf. Hippocrates, tt. aapKcov 2 (viii. 584 Littre) SoKeei 8e pot o KaX4oy.ev depfiov, dOdvaTov re ttvai . . . rovTO ovv . . . i^e\(Lpnqo€v els Trjv dvarraTOj irepit^prfv Kal avTO /xot So/cc'ct aldepa toIs TroAatois elpfjadax.) Its motion is circular ; so is that of the stars, which are composed of it (289 a 15). It is not found in the sublunary regions, but pneuma is its " counterpart " (see Introd. §§ 70 if., App. A §§ 7 if., and B). ' But see 761 b 15 flF., and note. » See App. A §§ 7 ff., B §§ 7-17.


737 a

ARISTOTLE aTTepixaros, dXXa kov tl TTepirrcofxa rvxTi "^V^ 4*^' 5 aecos ov erepov, opLcos e;^et /cat tovto l,a>Ti,Krjv ^PXW- ^"^^ f^^^ ^^^ 1 ^^ TOts" ^(pois deppLOTTjs ovre TTvp ovre aTTo irvpos €)(eL ttjv ap')(iqv, eK twv tolovrcxiv earl ^avepor.

To Se rrjs yovrjg aajfia, ev at avva7Tep\erai \r6 anepixoY ro rrjs ifjv)(^LKrj^ ap)(fis, ro [lev )(<optcrr6v ov 10 ocofiaros, oaots ep,TTepiXap.^averai ri^ deiov{roiovros S earlv 6 KaXovpievo^ vovs), ro S' axojpKJrov, rovro ro acbfJia^ rrjs yovrjs SiaAuerat /cat rrvevp-arovrai, (f)VGLV e)(ov vypav /cat vharchhrj. bioTrep ov Set ^rjrelv del dvpa^e avro e^ievai, ovhe piopiov ovOev elvai rfjs Gvardcnjs fiop(f)7Js, utaTrep ov8e rov 15 OTTOV rov ro ydXa avviardvra' /cat yap ovro? jLterajSaAAei /cat [xopiov ovdev can rwv avvicrrafievajv oyKOJV.

Yiepl fxev ovv i/jvx'rjs, ttcos e-^ei rd Kvqjxara /cat r] yovTj /cat 7TWS ovk €)(€t, SicopLarai' SwajieL puev yap ej^et, evepyeia S' ovk exei.* Tov he GTrepfxaros ovros Trepirro) pharos Kat /ctvovfxevov KLvrjcnv rrjv avrrjv Kad rjVTrep ro aa>p,a 20 av^dverat pepit^opevrfs rrjs eaxdr-qs rpo(f)rJ9, orav eXOrj elg rrjv vcrrepav, avviarrjat Kal /civet ro neptrrojfxa ro rov di^Xeos rr^v avrrjv Kivrjaiv rjvTrep avro Tvyxdvei Kivovp-evov /ca/ceti'o. /cat yap e/cetvo ^ TO a-nepfia om. P, secl. A.-^\^ : to irvevfia Platt, S.

  • XI P : TO vulg.

3 au)fia A.-W. : anep^ia vulg. * haec seclusit Platt.

° The " ultimate nourishment." Cf. 726 b 1 fF., and P. A. 650 a 34, 651 a 15, 678 a 8 ff. This is nourishment in its final form, viz., blood. 172


and not only the heat of animals which operates through the semen, but also any other natural residue which there may be has witliin it a principle of life. Considerations of this sort show us that the heat which is in animals is not fire and does not get its origin or principle from fire.

Consider now the physical part of the semen. (This it is which, when it is emitted by the male, is accompanied by the portion of soul-principle and acts as its vehicle. Partly this soul-principle is separable from physical matter - this appUes to those animals where some divine element is included, and what we call Reason is of this character - partly it is inseparable.) This physical part of the semen, being fluid and watery, dissolves and evaporates ; and on that account we should not always be trying to detect it leaving the female externally, or to find it as an ingredient of the fetation when that has set and taken shape, any more than we should expect to trace the fig-juice which sets and curdles milk. The fig-juice undergoes a change ; it does not remain as a part of the bulk which is set and curdled ; and the same applies to the semen.

We have now determined in what sense fetations and semen have Soul and in what sense they have not. They have Soul potentially, but not in actuality.

As semen is a residue, and as it is endowed with the same movement as that in wtue of which the body grows through the distribution of the ultimate nourishment," when the semen has entered the uterus it " sets " the residue produced by the female and imparts to it the same movement with which it is itself endowed. The female's contribution, of course, is a residue too, just as the male's is, and 17S


737 a

TreptTTCOjua, /cat rravra to. yuopia €)(eL Svvdixei, evepyeia S ovdiv. /cat yap ra roiavr' e;^ei fiopta 25 Sym^ei, t^ Sia^epet to ^t^Ai; tou dppevos. coajrep yap Kai e/c 7TeTTripcop.evoiv ore fxev yiverat 7T€7Tr)pcofxeva ore 8' oy, outoj Kai ck B-^Xeos ore /Ltev drjXv ore 8' oy, aAA' appev. ro yap OrjXv cSctttc/j appev eari TTeTTripcx>p.evov , /cat to, KarapirjVLa aTrepfia, ov Kadapov he. ev yap ovk e;^et p,6vov, rrjv rrjs ipvxrjs 30 ap)('qv. /cat 8ia rovro oaois VTTrjvepua ylverac rcov t,cpo)v, apL^orepayv e)(ei ra fieprj ro avviardfxevov d)6v, aAAo. rriv apx^jv ovk e^^ei, 8t6 ov yiverai efjiipvxov ravrrjv yap ro rov dppevos e7rLcj>epeL OTTepfia. orav he p^erdaxv roiavrrjs dpx'^S ro TTepLrrcojxa ro rod dn^Xeos, Kvrjfia yiverai.

35 ^[Tots 8' vypots piev acopLarcoheai, Se deppbaivopievots TTepuararai, Kaddnep ev rols iip-qpiaai, ijjv737 b ;^o/ueVots' to rrepi^rjpov. irdvra he rd aojpara cFvvex^i' TO yXiaxpov oirep /cat rrpo'Covai /cat pi,eit,oai yiyvop,evoLg rj rov vevpov Aa/xjSaret ^uat?, rjirep avvexei rd p,6pia tcDv t,cpojv, ev pLev rols ovaa vevpov, ev he rols ro dvdXoyov. rijs 8' avrrjg 5 piop(f)rjs earl /cat hepp-a /cat 0Aei/r /cat vpLrjv /cat Trdv ^ vv. 34-b 7 secluserunt A.-W.

° Other attempts to bring out the meaning of this word would include " imperfectly developed," " underdeveloped," " malformed," " mutilated," " congenitally disabled." i.e., as appears later, sentient Soul (ch. 5).

" i.e., as above (11. 23-25), potentially.



contains all the parts of the body potentially, though none 171 actuality ; and " all " includes those parts which distinguish the two sexes. Just as it sometimes happens that deformed " offspring are produced by deformed parents, and sometimes not, so the offspring produced by a female are sometimes female, sometimes not, but male. The reason is that the female is as it were a deformed male ; and the menstrual discharge is semen, though in an impure condition ; i.e., it lacks one constituent, and one only, the principle of Soul.* This explains why, in the case of the wind-eggs produced by some anknals, the Ggg which takes shape contains the parts of both sexes, '^ but it has not this principle, and therefore it does not become a Uving thing with Soul in it ; this principle has to be supplied by the semen of the male, and it is when the female's residue secures this principle that a fetation is formed. ^ [WTien substances which are fluid but also corporeal are heated, an outer layer forms round them, just as we find a solid layer forming round things that have been boiled, as they cool. All bodies depend on something glutinous to hold them together ; and as their development proceeds and they become larger, this glutinous character is acquired by the substance known as sinew, which holds the parts of animals together (in some it is actual sinew which does this, in others its counterpart).-'^ Skin, blood-vessels, membrane and all that class of substances are of the

    • Or, " it becomes a fetation," i.e., a perfect fetation ; see 7.S7 a 10.

  • The following paragraph, which consists partly of remarks taken from elsewhere, is irrelevant here.

' Sometimes, as here, " counterpart " could be represented by the modern term " analogue " ; cf. P. A. 653 b 36.


737 b

ARISTOTLE TO TOLovTOV yevo^' Bi,a(f)€p€i yap ravra rat jHoAAov /cat rJTTOv Kal oXios^ vTrepoxfj Kal eAAei^et.] IV Ta»v Se iC,ct)Oiv ra /xev dreXecrrepav e^ovra rrjv (f)vaLV, orav yevqrai Kviqyia reXeiov ^a»ov Se jlit^ttoj 10 TcXeLov, 6vpat,€ Trpoterai- St' a? 8' atria's e'lprjrai ■nporepov. reXetov 8' T^h-q ror' icrriv, orav ro fxev dppev fi ro 8e driXv rajv Kvqixdrcov, iv oaois larlv avrT] rj Bia(f>opd rcov yivofievcov evLa yap ovre OrjXv yevva ovr dppev, oaa firjS^ avrd yiverai eK d-qXeos /cat dppevos /X7y8' e/c ^ojcov fJbLyvvfxevcov. /cat Trepl 15 jjiev rijs rovrcov yeveaecos varepov ipovfxev Ta 8e t,cporoKovvra iv avrols rd re'Aeta rwv t^(x)(xiVy P'^xpi' TT^p dv ov yewrjarj t,wov /cat dvpal^e €K7T€fjnprj, ey^ei avfX(f)V€S iv avrols^ rd yiyvofxevov ^cpov.

"Oaa 8e dvpat,e jxev ^cporoKel, iv avroZg 8' <horoKel TO TTpcorov, orav yewqar) ro (l>6v reXetov, 20 rovrcov ivioiv fxkv dnoXverai ro (hov ojOTTCp rdJv 6vpat,€ (horoKovvroiv , /cat rd t,cbov iK rov (hov yiverat iv rep 6'qXei, ivicov 8' orav KaravaXcudfi rj iK rov (hov rpo^Tj, reXeiovrai (xtto tt^s" varipas, Kal 8ta rovro ovk diroXverat ro (hov dTTO rrjg varepag. ravrr]v 8' €)(ovaL rrjv 8ia(f)opdv ol aeXaxdihet? tp^ 25 dv€S, TTepl (Lv varepov Kad^ avrd XeKreov.

Nw 8' avro rdiv Trpdircjv dpKriov Trpdjrov. kari ^ oXcos PS : oAwj iv vulg. ^ avTols Rackham : avTu> vulg.

« Cf. P. A. 644 a 17, and note there; also Introd. § 70. * For the meaning of " perfect " animals, see below, 737 b 15, 16, and the fuller definition given at 732 b 28 ff. " i.e., a "perfect" egg; for another sense, see 776 b 1. ^ For Selachia, see Bk. Ill, ch. 3.



same stamp ; they diflPer only by the " more and less," or putting it generally, by excess and deficiency."] So far as those animals whose nature is more im- IV perfect are concerned, as soon as a perfect fetation *â– has been formed, though it is not so far a perfect animal, they expel it. The reasons for this I have already stated. A fetation is perfect by the time it is either male or female. (This applies to those animals whose offspring have this distinction of sex, for there are some which generate offspring that are neither male nor female ; these are the animals which are not themselves produced by male and female parents - not produced in fact as the result of the copulation of a pair of animals. We vriW speak later of the way in which these are generated.) The perfect animals, the ones which are intei-nally viviparous, retain \Aithin themselves the animal which is forming, and it remains joined to them until it is brought to birth and expelled.

With regard to those which are internally oxiparous in the first stage although they are externally vi\"iparous, the egg, when it has been perfectly formed, in some cases (a) is released, just as it is in the externally o\"iparous animals, and the animal is produced out of the egg inside the female ; in other cases (6), when the nourishment in the egg has been used up, the supply for the creature's perfecting is derived from the uterus ; and that is why the egg is not released from the uterus. This distinguishing feature belongs to the Selachian fishes, which will have to receive special mention later.** For the present, however, we must begin first of &*neration all with the animals that come first. These are the '° ^•p*'* 177

737 b

738 a

ARISTOTLE 8e TO. re'Aeta ^a>a TrpaJra, rotavra Se to, ^cx)otoKovvTa, Kal TovTcov avdpoiTTOs rrpoJTov.

'H fjL€V ovv CLTTOKpiais ytVcTat TTttcrt rod (nrepfxaros (xiairep aXXov rivo^ TreptTrdjjuaro?. ^eperai yap eKaarov ei? rov olkcXov tottov ovOkv aTTo^ia30 t,opuevov Tov TTvevjJLaTOs, ouS' dXXrjs alrias TOLavrrjs avayKa^ovcrr]s , coaTrep rtves (f)aaLV, e'A/ceiv to, atSota (fidaKovres ojoTrep Tct? aiKvas, ro) re nvevfiarL ^ta^o/xevcov, woTTep ivhe^ofJievov aXXodi ttov iropevdrjvai fxr) ^laaapiivcov -tf ravrrjv rrjv TrepLrrojatv rf rrjv rrjs vypds rj ^rjpd? rpo^rjSy on ra? e^oSoy? 35 avrihv r^dpoiapuevo) ro) 7TV€vp,ari ovveKKpivovaLV . rovro he kolvov Kara rravroiv oaa Sei KLvrjaai, Sta yap rov ro rrvevfia Karacrxelv rj la^vs eyyiveraf €7761 Kal avev ravrqg rrjg jSta? eKKpiverai rd rrepirrcop-ara Kal KaOevhovai, dv dveroi re Kal nXi^peis TTepirrcofjLaros ot rorroL rv)(a>aiv eyre's, ofjioiov Se Kav et ris (ftaL-q rots' (f)vrois vtto rov TTvevfiaros 5 eKaarore rd arrepfJiara aTTOKpiveadai Trpog rov? roTTOVs TTpds ovs etcode (j)epeLV rov Kapirov. dXXd rovrov jxev a'iriov, warrep elprjrai, ro Trdaiv elvac piopia SeKrLKa rols TTepirrajpiaoi roZg r dy^p-qarois (Kal rots ;i^p')7crt)U.otS'>^ [olov rfj re ^rjpd Kal rfj vypa, Kal rw aL/xari rds KaXovjxevas (^Ae'/Sa?]. 10 Tot? p^ev ovv diqXeaL rrepl rov rcbv varepwv rorrov, axi'^ofievwv dvwdev rwv hvo ^Xe^a)v, rrjg re pce ^ ^ P : om. vulg. * ^ P : om. vulg.

  • supplevi, cetera seclusi ; vid. p. 562, infra.

» Cf. Hippocrates, tt. apx- l-qrpiKfjs 22 (i. 626-628 Littre), where the action of the bladder, the head and the uterus in drawing fluid to themselves is compared to the action of atKvai,.



perfect animals, which means the viviparous ones; and the first of these is Man.

In all of them the semen is secreted in precisely the (<») The same way as any other residue. Each of the residues residues. is carried to its proper place without the exertion of any force from the pneiima and without compulsion by any other cause of that sort, although some people assert this, alleging that the sexual parts draw the residue like cupping-glasses " and that we exert force by means of the pneuma, as though it were possible for the seminal residue or for the residue of the liquid or of the solid nourishment to take any other course unless such force were exerted. The reason given for this view is that our discharge of these residues is accompanied by the collecting of the pneutna (the holding of the breath). But this is a phenomenon which is common to all cases where something has to be moved, because holding the breath is the way in which the required strength is obtained. Besides, even without the exertion of this force residues are actually discharged during sleep, if the places concerned are relaxed and full of residue. Such statements are on a par with saying that the seeds of plants are on each occasion secreted to the places where they commonly bear their fruit by means of pneuma. No, the real reason for this, as has been said, is that in all animals there are parts for the reception of the residues, both for the useless (and for the useful ones) [e.g., both for the solid and the fluid ; and for the blood there are the blood-vessels as they are called]. The region of the uterus in females. - Higher up in the body the two blood-vessels, the Great Blood

  • This phrase is an interpolation. See p. 562.


738 a

ARISTOTLE ydXrjs Kal rrjs doprrjs, rroXXal Kal XeTrral ^Ae'jSe? reXevTOJaLV els rds varepas, Sv VTrepTrXrjpovfMevojv €K TTJs rpo(f)rjg, Kal rfjg ^vaecos Sta ifjvxpoTrjra TverreLV ov Swajxev-qg , eKKptverai Sid XeTTTordrcov 15 (fyXe^cbv els rag varepas, ov hvvayievajv Sta tt^v arevo-)(a}plo-v Se)(ecrdaL rrjv V7Tep^oX7]v rod TtX-qdovg, Kai yiverai to Tradog olov alpioppotg. aKpi^cbg pbev ovv 7] TTeploSog ov reTa/crat rat? yvvai^l, ^ovXerac Se (f)div6vTa)v yiveadai t6jv fi7]va)v evXoycog' ipvXpdrepa yap rd ad)p,ara rcov t,cpa>v orav /cat ro 20 TTepiexov avjJi^aivri yiyveadai tolovtov, at Se rcov firjviov avvohoi ipv^poil Sta tt^v Trjg aeX-qvrjg dnoXeii/jLv, hioirep Kal -x^eipiepiovg avpL^aCvei rdg avvoSovg elvat rcov [jirjvdJv puaXXov rj rdg fxeaorrjrag. fiera^e^X-qKorog fxev ovv elg alfia rod 7repirr(Iipi,arog ^ovXerai ylyveadat rd Karapurivia Kard rr]v elpr] 25 fievrjv rrepiohov, p.7] TrerrepipLevov he Kard p,iKp6v del ri aTTOKpiverai' Sio rd XevKd puKpoZg eri} Kal iraihioig overt ylverat, rolg d-qXecrLV. pierpidt^ovaai /xev ovv ap,(f)6repaL avrai at drroKplaeig rcov irepirrcopidrcov rd acopara adi^ovaiv, are yiyvop.evr]g Kaddpaecog rwv 7Tepi,rra>p,dra)v a rov voaelv atria 30 Tots' acopaaiv p.r] ytvopievajv he -^ rrXeLovaJv yiyvo p,evcov jSActTTTef Troiet ydp rj voaovg r} rcov acopudrcov Kadalpeuiv, 8to /cat rd Aeu/ca avvex^og yivopceva Kal TrXeovdl^ovra rrjv av^rjaiv d^aipelrai rcov iraihlcov.

E^ dvdyKTjg p,€v ovv yj Treplrrcoaig avrrj ylverai

fUKpots €TtJ fjLiKpa crrjfieia


" i.e., the vena cava and the whole venous system, and the aorta and the whole arterial system.

  • The moon has no real connexion with menstruation. Various notions on this subject will be found in H. M. Fox, 180


vessel and the Aorta,** branch out into many fine blood-vessels, which terminate in the uterus. When these are overfull of nourishment (which owing to its own coldness the female system is unable to concoct), it passes through these extremely fine blood-vessels into the uterus ; but oAnng to their being so narrow they cannot hold the excessive quantity of it, and so a sort of haemorrhage takes place. In women the period is not accurately fixed, but it tends to happen when the moon is waning,* which is what we should expect, since the bodies of animals are colder when their en\-ironment is colder, and the time of new moon is a cold time on account of the disappearance '^ of the moon : the same thing explains why the end of the month is stormier than the middle.'* When the residue has changed into blood, the menstrual discharge tends to occur in accordance ^^^th the period just mentioned ; but when the residue has not been concocted, small quantities are secreted from time to time, and this is why " whites " occur in females, even while they are still quite small children. These two secretions of residue, if moderate in amount, keep the body in a sound condition, because they constitute an evacuation of the residues which cause disease. If they fail to occur, or occur too plenteously, they are injurious, producing either diseases or a lowering of the body ; and that is why continuous and abundant discharge of " whites " prevents young girls from gro^^•ing.

Thus the production of this residue by females is, Selene. For other references see F. H. A. Marshall, " Sexual Periodicity," in Phil. Tram. Royal Soc. (B), CCXXM (\o. 539), p. 442, n. "^ i.e., complete waning.

•^ See 777 b 35, n.



738 a

TOLs B-qXeai 8ia ra? elpr^fievas atria's' fJirj hvvayiivr)s 35 re yap Trerreiv rijg (Jivaecos avdyKT] TreptTTCo/xa ytyveadaL fir] fxovov ttjs axpr]arov rpocfirjg, dXXa /cat €v rals (jiXeijjiv, vrrep^dXXeiv re rrXi^dvovra^ Kara 738 b TO.? XeTTrordras ^Ae'^a?. eveKa Se rov ^eXriovog /cat rod reXovs rj (f>vais Kara)^prjraL rrpos rov rorrov rovrov rrjg yeveaecos )^dpt.v, ottcos olov efxeXXe roLOvrov yevqrat erepov tJSt] yap VTrdp^ei Swa/xei ye ov roiovrov olov vep eon (Tco/xaro? dTTOKpiois. 5 Tot? jxev ovv drjXeaiv dnaaLV dvayKalov yiyveadai TrepirrajpLa, rolg jxev aifxariKols TrXelov, /cat rouroiv avdpcoTTO) TrXelarov dvdyKTj Se /cat roXs aAAoi? adpoL^eadai riva avaraaiv els rov varepiKov rorrov. ro o aXriov, on rots B^ alp,ari,Kols TrXeiov Kal rovrwv on TrXelarov rots dvOpcoTTOts, elprfraL vporepov . 10 Tou S' ev p.eV rois d-qXeat rrdaiv vrrdp^eiv irepirTojjua roLovrov, ev Se rot? appeal jx-q Trdaiv, evta yap ov npoterat yovT]v, aAA' warrep rd Trpoie/j^eva^ rfj ev rfj yovfj Kiviqaei Sr]p.Lovpy€L ro avviardjxevov e/c rrjs ev rols drjXeaiv vXrjs, ovro) rd roiavra [ev]^ rfj ev avrols KLvqaet ev rd) ixopicp rovrco, odev 15 aTTOKpLverai ro aTrep/Jia, ravro Trotet /cat avvLarrjaLV . rovro S' iarlv 6 rorros 6 Trepl rd virot^ajp^a rrdai TOLS e)(ovaiv dpx'q yap rijs (f>vaea)s rj /capSia /cat ^ TrXrjdvovra Z : TrXrjBvvovTa vulg.

^ â– npolijxeva PS : Trpoeiprjfieva vulg.

  • secluserunt A.-W.

" <Sc., from the useful nourishment, viz., blood.

  • At 727 a 21 ff., and 728 a 30 ff.

" This sentence has been remodelled in the translation, since in the Greek the construction is not carried through. 182


on the one hand, the result of necessity, and the reasons have been given : The female system cannot effect concoction, and therefore of necessity residue must be formed not only from the useless nourishment, but also " in the blood-vessels, and when there is a full complement of it in those very fine bloodvessels, it must overflow. On the other hand, in order to serve the better purpose, the End, Nature diverts it to this place and employs it there for the sake of generation, in order that it may become another creature of the same kind as it would ha^e become, since even as it is, it is poteniiallt/ the same in character as the body whose secretion it is.

In all female animals, then, some residue must of necessitv be formed : a greater amount of it in the blooded ones, and the greatest of all in human beings, though some substance must of necessity collect in the region of the uterus in the other animals too. The reason why a larger amount is produced in the blooded animals, and the largest amount of all in human beings, has already been stated." But although a residue of this sort occurs in all females, it does not occur in all males. Why is tills r '^ Some males do not emit semen, but, just as the ones which emit semen fashion the creature that is taking shape out of the material supplied by the female by the agency of the movement resident in the semen, so these fashion it into shape by the agencv of the movement which resides in that part of themselves whence the semen is secreted ; thev produce this same effect of causing the material to set."^ (The part to which I refer is the region around the diaphragm in all those animals which have one, because

    • Cf. above, 736 a 27 and references there given.


ARISTOTLE 738 b , , ^ S^ ' n. . , TO ovaAoyov, to oe Kara) TrpoaorjKT] /cat rovrov X<ipi-v- aXriov Srj rod rots j^tev appeal fxr] rrdaiv elvai TTeplrroifjia yevvrjrLKov, rols Se dijXeai Trdaiv, 20 OTt TO t,<x)ov acofia epupvxov iariv. del Se TTape^^i ro fiev drjXv rrjv vXrjv, ro S' appev ro hrjfjuovpyovv. ravrrjv yap avrcbv (f}aiJiev exeiv rrjv ^vvafxiv eKoirepov, /cat ro etvat ro jxkv OrjXv ro S' appev rovro. ware ro puev OrjXv dvayKalov rrapex^i-v acbpia /cat or/Kov, ro 8' appev ovk dvayKalov ovre yap rd 25 bpyava avayicq evvTrapx^iv ev rols ytyvojxevois ovre TO TTOLOVV. ear I he ro [xev aajfxa e/c rov ^TjAeoj, r] Be fpvx"^ e/c rov dppevos' rj yap 4'^XV ovaia aojfiaros rivos eariv. /cat Sta rovro oaa rajv prj ojJLoyevcJbv payvvrai, drjXv /cat appev [puiyvvrai he div iaoL OL ;^pdvot Kat iyyvs at Kviqaeis, /cat rd fieyedr] 30 Tcov acofiarcov jxtj ttoXv hiearrjKev) , ro fiev Trpwrov Kara rrjv opLoiorrjra yiyverai kolvov d[X(f>OTepa)v, otov rd yiyvopbeva e^ oXwireKos /cat Kvvds /cat TTephiKos /cat dXeKrpvovos, rrpoiovros he rov xpovov /cat i^ erepcov erepa yiyvopbeva reXog diro^aivei /card ro drjXv r'r]v' p.op(f)rjV , cjaTrep rd aveppiara rd 35 ^eviKd /card rrjv p^copav. avrrj ydp rj rrjv vXtjv " Or " reality." Cf. De anima 415 b 7 ff., where the Soul is said to be the Cause and principle of the body (a) as the source of its movement, (6) as its Final Cause, that " for the sake of which " the body exists, {c) as being the essence of living bodies. The last is explained thus : the cause (or ground) of the being of anything is its essence ; the being of living things is to live ; and the Cause and principle of their being and living is Soul. Cf. also Aristotle's repeated 184


the first principle of any natural creature's system is the heart or its counterpart, while the lower parts are an appendage added for the sake of that.) Why does this generative residue, then, not occur in all males, although it occurs in all females . The answer is that an animal is a living body, a body with Soul in it. The female always pro\ides the material, the male provides that which fashions the material into shape ; this, in our view, is the specific characteristic of each of the sexes : that is what it means to be male or to be female. Hence, necessity requires that the female should provide the physical part, i.e., a quantity of material, but not that the male should do so, since necessity does not require that the tools should reside in the product that is being made, nor that the agent which uses them should do so. Thus the physical part, the body, comes from the female, and the Soul from the male, since the Soul is the essence " of a particular body. On this account, when a male and a female of different species copulate (which happens in the case of animals whose periods are equal and whose times of gestation run close, and which do not differ widely in physical size), the first generation, so far as resemblance goes, takes equally after both parents (examples are the offspring of fox and dog,* and of partridge and common fowl), but as time goes on and successive generations are produced, the offspring finish up by taking after the female as regards their bodily form, just as happens when seeds are introduced into a strange locahty - the plants take after the soil, the reason being that statements that no part of the body can be such in anything but name unless it has Soul in it ; see also P. A. 641 a 25 ff.

  • Viz., the so-called Laconian hound ; see H.A. 607 a 3.



738 b

7Tap€)(ovaa Kai to crcofxa tols' avepixauLV eariv. kul Sia rovTo rots' /x.ev OtjAeai to (xopiov to heKTiKov ov 739 a TTopos €otlv, aXX e^ovaL StdaTaatv at voT^paf Tolg 8 appeal Tropoi toIs cnreppLa tt po'CepbivoLS , avaLpLoi 8' o^Tot.

TcDr 8e TTepLTTOipLOLTOiv eKaoTov a/xa eV re rots' OLKeioi-s TOTTOLS €<jtI Kol ylyv€TaL 7T€pLTTa>[Ma- Ttpo Tepov 8 ovdev, av pbrj tl j8ta ttoXXtj /cat rrapa ^vaiv.

5 At r^v jxev ovv atrtav aTro/cptVerat ra TreptTTCo /nara ra yevvrjTLKa tols t,q)ois, eLpT]Tai,.

"OTav 8' eA^T] TO aTTeppua OlTto tov dppevos tcvv airippia irpo'Cefxevoiv, avvLaTTjai to KadapcoTaTov tov TTeptrrco/Liaros - to yap TrXelaTov dxp'f]OTOv Kal iv TOLS KaTapLTjVLOLS ioTLV vypov (pvy^, wairep /cat ttjs 10 TOV dppevos yovrjs to vypoTaTov Kal ttjs elaaTra^ TTpoeaecos l/cat]^ r] npoTepa ttjs vaTepas dyovos fxdXXov TOLS TvAetCTrots"" eAarrcD yap ^X^ ^^pP'OTTjTa iJjvxt'Krjv Bid TTjv aTTeipLav, to 8e TTeTT€p,pL€.vov Trd^os ex^L Kal aeawpLaTOJTaL fxdWov.

"Oaats Se pur^ ytVerat dvpa^e tls Trpoeais, rj tow yvvaiKcbv •^ tcov dXXcov ^djojv, 8ta to pirj evvrrdp-^eLV 15 axpT](TTOv rrepi'TTOJjjLa ttoXv ev ttj aTTOKpLaei Tjj TOLaVTYj, TOGOVTOV ioTL TO €yyLv6pL€VOV OGOV TO VTToXeLTTOpLCVOV TOLS dvpat,e TTpo'CepLeVOlS t^CpOLS, o avvLOTiqaLV rj tov dppevos SvvapiLS rj ev to) CTTrep/xart ^ <ov> supplevi. * seclusi.

<• See Bk. I. 718 a 10 ff.

  • Cf. Hippocrates, tt. aapKuiv 13 (viii. 600 Littre) ij 8e Tpo<f>ri eTTfiSdv acfyiKTjraL es eKaaTOV, Toiavr-qv arreBcoKe ttjv eiBerjv eKaarov okoicl -nep r)v.

" The 'â– concoction " of the semen in viviparous landanimals takes place actually during copulation (see 717 b 24 186


the soil provides the material - i.e., the physical body - for the seeds. And on this account the part in females which receives the semen is not a passage, but it - i.e.. the uterus - is fairly \\ide, whereas the males that emit semen have passages only, and these have no blood in them." It is only when it occupies its own proper place that each of the residues becomes that particular residue *• : before that time none of them can do so without great violence exerted contrar}- to nature.

We have now given the reason for the secretion of the generative residues in animals.

In those species which emit semen, when the semen from the male has entered, it causes the purest portion of the residue to " set " - I say " purest portion," because the most part of the menstrual discharge is useless, being fluid, just as the most fluid portion of the male semen is, and in most cases the earlier discharge during any one emission is less fertile than the later, because it has less soul-heat owing to its being unconcocted, whereas that which has been concocted is thicker and has more body in it."^ In those cases (whether women or other female animals) where there is no external discharge (due to there being no large amount of useless residue in the generative secretion), the amount of stuff which is produced within them corresponds in quantity to that which remains behind in those animals which discharge externally. This stuff gets " set " by the dynamis of the male (a) present in the semen which and 718 a 5 above), which explains the phenomenon here mentioned. In fishes and serpents the semen is already concocted before the time of copulation (ibid.).



739 a

Toi anoKpivoficvcp, 7^, elg to dppev iXdovros tov dvdXoyov fxoptov raXg vurepais, MOTrep ev riai tcDv 20 ivrop^cov ^aiverat avpL^aXvov.

"On S' rj yivofjievr} vyporrjs fierd r-qs rjSovrjg rots d-qXeaiv ovhev ay/i^SaAAerat ei? ro KV7]p,a, etprjTai rrporepov. fidXicrra 8' dv So^eiev, on Kaddirep tols appeal, yiyverai. /cat ratS" yvvoLL^l vvKTCop o KaXovaiv i^oveipcoTTeiv. dXXd rovro arjiJietov ovOev yi 25 verat ydp koX toZs veois rdJv dppevcov roZs {jieXXovai p,€v (JLTjOev Se TTpo'Ceixevois, t) tols en^ TrpoCepievoLS dyovov.

"Avev fxev ovv rfjs tov dppevos Trpoiaeoi'; ev ttj (Tvvovaia dhvvaTov avXXa^eiv, /cat dvev Trjg tu)v yvvaiKeiuiv TrepLTTCoaecog rj dvpat,€ TrpoeXdovarjs rj ivTos iKavrjs ovarjg. ov avfx^aivovarj? /xeWoi tt^s 30 elcudvlas yiyveaOai rot? 6i]Xeaiv rjSovrjs rrepl Tr]v o/xtAtW Tr]v TOLavTTjv GvXXap^dvovaLV , dv tvxj) 6 TOTTos <(y') dpycov^ /cat KaTa^e^riKvlai at voTepac evTos-^ dXX d)S em to ttoXv avfji^aivet, eKetvoJS §ia TO puTj avpLp^epLVKevat to aTOfia yLvopievrjs ttjs eKKpiaeios, p-ed^ rjs e'icode yiyveadaL /cat rots' appeatv 35 rj r]8ovrj /cat rat? yvvai^LV ovtco S' e-)(ovTo? euoSetrat p^dXXov /cat TO) TOV dppevos OTreppiaTL.

  • H 8' d(f)eaLs ovK evTos yiyveTai, Kadarrep otovrat

Ttves {oTevov ydp to CTTO/xa tojv voTepdyv), oAA' et? 739 b TO TrpouBev, ovirep to drjXv TTpoteTai T'171' ev eviais avTcov LKp^dSa yivofievqv, evTavda /cat to dppev TrpoteTai [edv Tig e^iKfxdar]].* otc p.ev ovv pevei ^ en TTpo'Cefxevois corr. P : emrrpo'CeiJ.evois vulg.

^ TOTTos y' opyojv A.-\V. : tottos 6 yeoipyoiv P : y' om. vulg.

^ evTos P : eyyvs '^^ilg.

  • seel. A.-W., Platt.



is secreted, or (b) when the part of the female analogous to the uterus is inserted into the male (as is observed to take place in certain insects)." I have said already that the fluid which is produced in females and accompanies sexual excitement contributes nothing at all to the fetation. The strongest reason for believing that it does is that the phenomenon of night effusions occurs in women just as in men ; but this is no proof at all, because it occurs with young men who come almost to the point but in fact emit nothing, and also with those who as yet emit infertile semen.

Conception cannot occur without (a) an emission from the male during copulation and without (b) the presence of the menstrual residue either externally discharged or available in sufficient quantity internally. Conception takes place, however, even if the pleasure which women usually experience during sexual intercourse fails to occur, if the part concerned happens to be in heat and the uterus has descended within. Generally, however, pleasure does occur, because when the secretion, which is usually accompanied by pleasure in man and woman alike, takes place, the os uteri has not closed, and in these conditions a better passage is afforded for the semen of the male.

The discharge does not (as some suppose) take place within the uterus, because the os uteri is narrow. The discharge of the male takes place in front of it, at precisely the same spot where the female discharges the moisture which is produced in some instances.*^ Sometimes it remains in this place, « Cf. 738 b 12. Bk. I, ch, 20.

' Cf. 727 b 33 ff.


739 b

ARISTOTLE rovTov exov^ rov tottov^ ore Se, av Tvyy] avjxfxerpco? exovaa /cat depfjurj 8id Tr]V Kadapaiv rj v6 arepa, eLcrco aird.. arjuelov 8e- Kal yap ra TrpoadeTO? vypa TTpoaredevra d(f)aLp€Lrai, ^rjpd. en Se oaa rojv ^(pcov Trpos" rep VTTot^iLpari e^ei ra? vcrrepas, Kaddrrep opvts Kal tcov l^Qvcov ol ^cooroKovvres, aovvaTOV CKel pur] airdadai ro aneppia, dAA' dcjiedev eXdelv. eXket, Se rrjv yovrjv 6 tottos Sid Tr)v dep 10 pLOTTjTa TTjv VTrdp^ovoav . Kal rj rcov KarapLrjviwv Se CKKpLOLs Kal avvdOpoLGLs ifXTTvpcvei deppoTTjra €V TO) pLoplcp TovTip, [tScTTe]* Kaddivep Ta KcoviKa^ roiv ayyeiwVy orav deppbco hiaKXvadfj , ana to vSwp et? avTOL Karaarpe<f>opLivov rov aroparos. Kal rovrov p.ev rov rponov yiyverai aTrdaig, (Ls Se' rives 15 Xeyovai, roZs opyavLKols Trpos rrjv avvovaiav pLOpiois ov yiverai /car' ovdeva rponov. avdnaXtv Se avpL^aivei Kal tols Xeyovac Trpoteadat, Kal rrjv yvvacKa OTTeppLa. Trpo'CepLevaLS yap efco avpL^aivet rals varepais TraXiv etaco airdv, e'liTep pt)(diqaeraL rfj yovfj rfj rov dppevos. ro 8' ovrco yiyveadai 20 TrepUpyov, r] Se <f)vat,s ovBev Trotet irepiepyov.

"Orav Se avarfj rj iv rats" varipais aTTOKpicFis rov 6-qXeog vtto rrjs rov dppevos yovrjs, rtaparrXr^aiov TTOiovar]? cooTrep evl rov ydXaKTog ri]s TTvertag- Kal yap rj TTveria ydXa earl deppLorrjra ^(vriKriv e)(ov, tJ ro opioiov els ev dyec Kal avvlarqai, ^ exov Y : Ip^ovra vulg. ^ tottov Platt : rponov vulg, ' -npooOeTa P : Ttpoadev vulg. * cSore seclusi.

  • KtDviKo. Platt: aKovira vulg. : van quod non est plenum S ( = Ktva ?).

« Gf. 728 a 31 ff.

sometimes, if the uterus happens to be in a suitable condition and hot owing to the evacuation of the menses, the uterus draws it in. Evidence for this is the fact that pessaries though wet when applied are dry when removed. Also, in those animals (such as birds and \iviparous fishes) whose uterus is close by the diaphragm there is no alternative : the semen must be drawn in ; it cannot enter at the moment of discharge. This region, in \irtue of the heat present in it (the discharge and aggregation of the menstrual fluid also produce fiery heat in this part) draws up the semen in the same way that conical vessels which have been washed out with something warm draw water up into themselves when they are turned mouth downwards. And that is the way in which the semen is dra\\Ti in ; it is certainly not done, as some allege, by the parts that are instrumental in copulation." We find the situation reversed in the theory that the woman as well as the man emits semen, since if the uterus emits any semen outside itself, it will have to draw it back inside again if it is to mingle with the semen of the male. Such a performance is superfluous, and Nature does nothing which is superfluous.

The action of the semen of the male in " setting " the female's secretion in the uterus is similar to that of rennet upon milk.* 'Rennet is milk which contains vital heat, as semen does, and this integrates the homogeneous substance and makes it " set." As the ' Cf. 755 a 18. This is a remarkable intuition of the essential role played by ferment action in embrjonic development. Cf. ako Job X. 10 " Hast thou not poured me out as milk, and curdled me like cheese ? Thou hast clothed me with skin and flesh, and knit me together with bones and sinews " (R.V.).



739 b

25 icat 7] yovrj irpos rrjv rojv KarafxrjVLCDv (^vaiv ravro^ TTeTTOvdev rj yap avrrj (f)vais earl ydXaKTOs Kal KarajXTjVLWv . gwlovtos §17^ tov crco/xarcoSoys" e/cKpiverat to vypov, Kal TrepdaTavrai kvkXco ^rjpaLvojxevctiv rajv yerjpcov vfieves, Kal i^ dvayK-qg Kal €V€Ka rivos' /cat yap depixatvopiivoyv ^TjpaLveadaL 30 avayKalov rd ea)(ara Kal ^vxofJ-evojv, Kal Set p.r] €V vypcp TO ^wov elvai dXXd Ke)(a)piaiX€vov. /caXovvTai 8e TOVTCDV ol fji€v vfxeves Ta Se ■)(opLa, OLacpepovTa tco fxdXXov Kal tjttov ojuotoj? 8' ivuTrdp■)(ovaiv kv T€ Tols (hoTOKois TavTa Kal tols ^wo TO/COtS".

"Orav 8e avoTfj to Kvrjfxa tJSt], TrapaTrXrjaLov 35 TTOcet tols aTreipofievoLS. tj jxev yap dp)(rj Kal iv TOLS aireppiaoLV ev avTols iorlv rj TrpcoTrj- orav 8' avTy aTTOKpLdfj ivovaa 8ut'a/xei trpoTepov, dTTO Tav TTjs dcf)i€TaL 6 T€ jSAttCTTO? Kal 7] pti^a. aUTT) 8' 740 a eoTLV fj tt^v Tpo(f)rjv Xajx^dvei' SeXraL yap av^rjueajs TO (f)VTOV. OVTW Kal €V TOJ KVqfjLaTL TpOTTOV TLvd TTavTCDV evovTOJV TOJV fJLopLwv SvvdjjLeL Tj dp)(rj TTpd ohov /xaAicrra evvTrdp-^eL. Sio diroKpiveTaL rcpcJOTOV Tj Kapdla evepyela. Kal tovto ov p,6vov em ttjs 5 alad'qaews SrjXov {avpi^aiveL yap ovtcos), dXXd Kal em tov Xoyov. OTav yap q-tt^ dp^^olv dTTOKptOfj, Set avTO avTO SioiKelv to yevofievov , Kaddrrep 0.77 ^ ravTO P: tovto vulg. ^ S^ A.-W., O* : 8e vulg.

" <j>vai,s, as often, refers specially to the substance of the thing. The substance of milk and the menstrual lluid is identical, because they are both residues of the useful nourishment.


nature " of milk and the menstrual fluid is one and the same, the action of the semen upon the substance of the menstrual fluid is the same as that of rennet upon milk. Thus when the " setting " is effected, i.e., when the bulky portion " sets," the fluid portion comes off ; and as the earthy portion solidifies membranes form all round its outer sui'face. (This is the result of necessity ; but also it is to serve a purpose : (a) Necessity ordains that the extreme surface of a thing should sohdify when heated as well as when cooled ; (b) it is requisite that the young animal should not be situated in fluid but well away from it.) Some of these are called membranes ; some choria ^ : and they differ by the " more and less." '^ They are found in Ovipara and Vivipara aUke.

Once the fetation has " set," it behaves Uke seeds (6) The sown in the ground. The first principle (of growth) nfeTit of is present in the seeds themselves too, and as soon '^^ embryo, as this, which at first was present potentially, has become distinct, a shoot and a root are thrown out from it, the root being the channel by which nourishment is obtained, for of course the plant needs material for grovrth. So too in the fetation, in a way all the parts are present potentially, but the first principle has made the most headway, and on that account the first to become distinct in actuality is the heart. This is plain not only to Heart. the senses (for after all it is a matter of fact), but also to the reason. Once the fetation which has been formed is separate and distinct from both the parents, it must manage for itself, just like a son who has set up a house of his own independently of his » See also H.A. Bk. VI, ch. 3. ' See 737 b 7, n., and Introd. § 70.

H 193

740 a

ARISTOTLE OLKLodev reKvov arro Trarpos . ware Set dp)(7jv €)(€lv, a<p rjs /cat voTepov rj SiaKoafi'qais rod aajjuaro? yLverai rots ^cools. et yap e^codev TTor earai kol 10 varepov eveaofjuevrj, ov jJiovov SiaTropijaeLev dv ris ro nore, dAA' on dvdyKrj, orav eKaarov )((jopL^rjrat, rojv fjLopLOJv, ravr'qv inrapx^LV Trpcorov, i^ ■j^? Kal rj av^7]ais vrrapx^L Kal -f] KLvrjois rols aXXois [xopiOL'S. hiorrep oaoL Xeyovatv, uJOTrep Ar][ji6KpLros, ra k^co Trpcvrov htaKpiveaOai roJv l^cpcov, varepov 15 06 rd evros, ovk opddjs Xeyovaiv, wairep ^vXlvojv T] Xidivoiv ^(Lcov. rd fiev yap roiavr' ovk e^^et ap'XTfv bXios, rd he t,cpa rrdvr* e;)(et Kal evros e;)(et. Old Trpdjrov rj Kaphia (jyaiverai, Siojptanevr] rrdai rots evaipots' dpx"^ ydp avrr] Kal rcbv ojJLOiojJiepcbv Kai ra)V avopLOiopepcov. rjSrj ydp dpx^v ravrr^v 20 d^tov dKovaai rod iC,<l)ov Kal rod avarrjfjiaros, orav BerjraL rpocjyrjS' ro ydp Sr] ov^ av^dverai. rpo(f)rj 8e t,cpov rj iaxdrrj aifxa Kal ro dvdXoyov. rovrcov o' dyyelov at (f)Xe^es' Sto tj KapSia Kal rovrcov ^ ov] la)ov Y.

« See Diels, Vorsokr.^ 68 A 145.

" See Introd. § 19.

" The point is that by this time the fetation is definitely constituted - it is an individual - it exists, and that which exists can correctly be said to have an dpx'i]- Also, that which exists needs nourishment, and in animals nourishment means blood, of which the heart is the apx^]- (As Aristotle says elsewhere, 735 a, the heart supplies the principle of growth, and the nutritive faculty of Soul operates through the heart.) This, then, is why, as soon as the fetation is definitely constituted, the heart is formed - otherwise no growth could take place.

It is unnecessary to read ^oJov for ov : 6v gives better point to the argument, with which compare the passage 194


father. That is why it must have a first principle, from which also the subsequent ordering of the animal's body is derived. Otherwise, supposing this principle is to come in at some moment from outside and take up its position inside later on, then we may L'U be puzzled at what moment this is to happen, iid also we may point out that of necessity the first principle must be present at the outset, at the time when each of the parts is being separated from the rest, since the growth and movement of the other parts are derived from it. That is why those people are wrong who, like Democritus," hold that the external parts of animals become distinct first, and then the internal ones. They might be speaking of animals carved out of wood or stone, the sort of things which have no first principle at all, whereas living animals all have such a principle, and it is inside them. On this account in all blooded animals it is the heart which can first be seen as something distinct, as this is the first principle both of the " unif(jrm " and of the " non-uniform " parts ^ - since this is justifiably designated as first principle of the animal or organism from the moment when it begins to need nourishment,'^ for of course that which exists grows,'^ and, for an animal, the ultimate form of nourishment is blood or its counterpart. Of these fluids the blood-vessels are the receptacle,^ and therefore T:>5 a 13-26 (where again the reading with Sv should be kept in 735 a 23). Here the point is clearly made that, once a thing has come into being (yenjrai), it must of necessity grow. See also note on 744 b 36.

' The blood-vessels distribute the " ultimate nourishment " to the parts of the body, which, as Aristotle says (743 a 1), are moulded round them like a wax figure round a core or foundation, and are formed out of them.



740 a

o.p)(7]. SrjXov Se rovTO ck rcov laropiajv Kal rcJiJv avaroiichu.

'Ettci 8e dvvdfjiei jxev tJSt] l,a)ov dreXeg Se, aA 25 Xodev dvayKalov Xajx^dveLV rrjv rpocfirjv Sto ^^pT^rat Tjj varepa /cat rfj ixovcrr), cooTrep yfj ^vrov, rod Xap,^dv€LV Tpo(f)7Jv, ecus dv reXecodfj Trpos to elvat rjSr] ^(pov Svvdp.€L TTopevrcKov. Sio €k rrjg KapSlas rds 8vo (^Xe^as rrpcoTov^ rj (j}vcns vneypaipev aTTo' Se Tovrojv (j)Xe^La dv^prrjrat Trpo? rrjv varepav o 30 KaXovfievog d/ii^aAds". eari yap 6 o/Lt^aAds' ^Ae'i/r, Tols /x€v /xta, TOLS 8e TrXelovs ratv t,cpajv. irepl 8e ravras K€Xv(f)os heppiariKov [d KaXovpevos d/x^aAd?]^ Sid, TO SeZadai acor'qpLas Kal aKeTTTjs rrjv rwv (fiXe^wv daOevetav. at Se ^Ae^Se? otov pit,at, irpos 35 T7}v varepav avvdrrrovcn, 8t' (Lv Xap^jBavet ro Kvrjfxa rrjV rpocf}iijp. rovrov yap X^P^ ^^ rals varepais jLteVet TO ^a>ov, dAA' ovx d>? ArjfxoKpiros (jyrjOLV, Iva ScaTrXdrrrjraL rd fxopia Kara rd pLopia rrjs exovarjg. 740 b rovTO ydp €7rt rwv woroKovvrwv (f)av€pov eKelua ydp iv roLS (pois Aaju.j3avet rrjv 8ta/<:ptcrtv, Kexojptafieva rrjs fjL-qrpag.

^ ArropiqaeLe 8' dv ris, et to alfxa [xev rpo(/)r} iariv, 7] 8e KapSla TrpcLrr) yiverai erat/xo? ovaa, [ro 8 at/xa rpo(f)i^,f 7] 8e rpocfii] dvpadev, TToOev eiaTjXdev 5 7] TTpcor7j rpo<j>7i; •^ rovr* ovk dXTjoeg, cos" Trdaa ^ TTpdiTas p. ^ seclusit Bekker.

' secluserunt A.-W. : pro to 8' ai/xa . . . dvpaOev et sanguis est ex extrinseco S.

» H.A. Bk. Ill, ch. 3.

Or, " sketches in," " traces out." Cf. 743 b 20, and a different metaphor at 743 a 2.

" Cf. 745 b 25 if. "^ vSee Diels, Vorsokr.^ 68 A 144.



the heart is the first principle of them as well. This !•- clearly brought out in the Researches " and in the Dissections.

Now since the fetation is already an animal potentially, though an imperfect one, it natist get its nourishment from elsewhere ; and that is why it makes use of the uterus, i.e., of the mother, just as a plant makes use of the earth, in order to get its nourishment, until such time as it is sufficiently perfected to be a potentially locomotive animal. That is whv Nature prescribes * first of all the two blood-vessels that run from the heart ; and attached to these are some small blood-vessels which run to the uterus, forming what is known as the umbilicus, the umbihcus ^ being of course a blood-vessel - a single blood-vessel in some animals, and consisting of more munerous ones in others. Round these blood-vessels there is a skinlike integument, because the blood-vessels being weak need a protective covering to keep them safe and sound. The blood-vessels join on to the uterus as though they were roots, and through thenx the tation gets its nourishment. And that of course - the reason why the young animal stays in the uterus (not as Democritus ^ alleges, in order that its parts may be moulded after the fashion of the parts of its mother). This is manifest in the case of the 0\ipara, whose parts become distinct in the egg, i.e.,

"ter they have been separated from the matrix. Here is a puzzle which may be raised. If (1) the blood is nourishment, (2) the heart is the first thing to be formed, and when formed contains blood, and (3) the nourishment comes from outside, from whence did the first nourishment * enter ? Well, perhaps
  • i.e., the blood which is in the heart to begin with.


740 b

ARISTOTLE uvpadev, aAA' evdvs, wairep iv Toig tcov (J>vt(jl)v CTTTepfiaaLv eveari tl toiovtov to (fjaivoixevov TrpojTov yaAa/CTtoSes", ovtcl> koI iv rfj vXrj rwv ^ojcuv TO TrepcTTCOfxa Trjg crycrTacrecD? Tpo(f>ri ioTiv.

H ixkv ovv av^Tjots tw KvijfiaTi ytVerat Sia tov 10 ofi(f)aXov TOV avTov Tpoirov ovrrep 8ta tcJov pi^cbv Tols (fiVTOLS [koL tols t,a>ois aVTOLS, otov (XTTOAvda)aLV, ck ttjs €V avTols Tpo(f)rjsj^ • rrepl Sv voTepov AeKTeov /cara tovs oIkclovs tcov Xoyojv Kaipovs. 17 oe ScaKpLons yiyveTat tCjv fxopLOJV ovx u>s Tives v-TToXafi^dvovaL, Sta to rre(f)VKevai ^ipeadai to 15 o/xoLov Trpos TO o/xoiov {TTpos yap TToAAat? d'AAais" ais" o Xoyos ovTos ex^i, Svax^p^iats, CFvp-Paivei XOip? eKaoTOV yCveadat tcov [xopuov tcov ojxolofxepcov, oLov oaTo. Kad avTO. Kal V€vpa, /cat rd? aapKas Kad aurd?, el' tis dnoSe^aiTo TavTrjv ttjv aiTtav), dXX OTi to TrepiTTCopia to tov drjXeos 20 Svvdfiei TOLOVTOV ecrrtv otov (f)vaei to t,cpov, Kal eveoTL SvvapieL to. f.i6pia, evepyeia S' ovdev, Std TavTTjv T7]v atTtav ytVerat eKaoTOV avTcov, Kal otl TO TTOLrjTlKOV /fttt TO TTaOr^TLKOV, OTav diycooLV, ov TpoTTOv eoTL TO pkv TTOnqTiKov TO Sc vadrjTiKov [tov Be TpoTTov Xeyco to a)s Kal ov Kal oTe), evdvs to 25 jxev TTOLCL TO 8e -ndax^i. vXrjv p,ev ovv Trapejs^et to ^ seclusi : suspicatus est Platt : tov avrov . . . rpot^'^s om. S.

" This phrase seems to be an interpolation, connected perhaps with II. 29-31 below.

  • This commonplace of thought in Greek philosophy and medicine is a pseudo-scientific form of a proverbial maxim (c/. " birds of a feather "), specially alluring to the Greeks. Cf. especially Hippocrates;, n. <j>vaLos ttmSlov, ch. 17 init. and Jin. (vii. 496-498 Littre). See quotation \n note on 742 a 1.



after all it is not true to say that all the nourishment comes from outside. In the seeds of plants there is some nutritive matter, which at first has a milky appearance ; and it may be that in the same way, in the material of the animal, the residue left over from its construction is present as nourishment for it from the outset.

So then, the fetation's gro^vth is supplied through the umbilicus in the same way that a plant's growth is supplied through its roots [and also as that of animals is, when they have been separated, from the nourishment which is in themselves]." Of these matters we shall have to speak later at the appropriate occasions in our discussions. As for the ditferentiation of the various parts : this is not due, as some suppose, to any natural law that " Uke makes its way to Uke." * This theory involves quite a number of difficulties, one being that if you accept it as stating a valid reason, it follows that each of the " uniform " parts, such as bones, and sinews, and flesh, is formed separately, each one all on its own. The true reason why each of these parts is formed is that the residue provided by the female is potentially the same in character as the future animal will be, according to its nature : and although none of the parts is present in actuality in that residue, they are all there potentially. A further reason is this. When a pair of factors, the one active and the other passive, come into contact in the way in which one is active and the other passive (by " way " I mean the manner, the place, and the time of the contact), then immediately both are brought into play, the one acting, the other being acted upon. In this case, it is the female which provides the matter, and the male which provides the 199


740 b

drjXv, Tr)v 8' apxrjv rrjs KLv-qaeais to dppev. CiiOTTcp 8e ra vtto ttj? rex^rjs yivopieva yiverai 8td rcbv opyavcov, eart 8' aXridiarepov eiTreiv Sia ttjs Ktv-qaecos avTWv, avrr] 8' iarlv 7] evepyeta rrjs rex^rjs, r/ 8e rex^T] l^opcf)r] rcvv ytvopuevcov iv dXXcp, ovrojs 30 7] TTJs OperrrLKT^s 4'^Xl'^ SvvafJLCs, (Zaircp /cat eV avTols rols t^cpoL's koI tols (f)VTOLS varepov e/c ttjs rpo(f)rjs TToiel ttjv av^rjaiv, xP^I^^vt) olov opydvois depixoTrjTi, /cat i/jvxporrjri {iv yap tovtols tj KLvrjacs eK€LV7]s, /cat Xoyo) tlvl eKaarov yiverat), ovrco /cat i^ oLpxrjs avviarrjaL to <j)va€i yiyvofievov rj yap 35 auTTy eariv vXr) fj av^dverai /cat e^ t^s" avviaraTaL TO TTpwroVy oj(TT€ /Cat 7^ TTOLOvaa SvvajjLts ravTO [ro) e^ dpxrj?' p^eit^cov he avrr] earivf' el ovv avTiq eoTLV -q OpeTTTiKT] ijjvx')], avrr] earl /cat rj yewwaa' 741 a /cat rovr eariv rj (f)vaLs rj eKaarov, evv-ndpxovaa /cat ev (f)VTols /cat eV ^ojot? rrdaLV. ra 8' d'AAa [lopia rrjs i/^vxV^ '^^^^ H'^^ vrrdpxet rots 8' ovx vrrapxei rchv iC,(x)vto)v ." Ev /xev ovv Tols (jiVToZs ov Kexiiypf-orai to drjXv 5 Tov appevos' ev 8e rot? ^cools ev ots Kexcoptcrrai, V TTpoaSeiTai to drjXv rod dppevos.^ KaiToi tls aTTo ^ seclusi. [j,eii,a)v . . . iarlv seel. A.-W., qui et ravro rio i^ dpXV^ yevvijaavTt eariv: Btf. rjj i^ o.px'fjs [/x. . . . e'.].

  • ld)VTcov Peck : ^ciouv vulg. :. cf. 731 a 31, ubi PY ^aitov pro t,<uvT(xiv : in quihusdatn corporibtis quae virunt 2.

  • TO dijXv TOV appevos Peck, docente Platt : tov drjXcos to dppev vxilg.

» Cf. 734 b 36 ff. and P. A. 640 a 33.

" See yVpp. B §§ 6, 9, 15.

" Cf. Phys. 193 b 21 IF. cos ovcrrjs ttjs ^Jaeoi? apxfjs tivos Kal aiTias TOV Kiveiadai Kal â– ^pefieZv ... 33 <j>vaiv 8e ex^'- ^^"^ "oiavTrjv 200


principle of movement. Now the products which are formed by human art are formed by means of instruments, or rather it would be truer to say they are formed by means of the movement of the instruments, and this movement is the activity, the actualization, of the art, for by " art " we mean the shape of the products which are formed, though it is resident elsewhere than in the products themselves." The dynamis of the nutritive Soul behaves in the same way. Just as, in the independently existing animal or plant, this Soul, which uses heat and cold as its instruments (for it is in these that its movement subsists, each several thing being formed according to some definite logos), at a later stage produces gro\\"th out of the nourishment suppUed, so in precisely the same way at the very outset, this Soul, while the natural object is being formed, causes it to be set and constituted ; since, as the matter from which the object derives its growth is identical \nih that out of which it was originally set and constituted, so too the dynamis which fashions the object is identical. If, then, this is the nutritive Soul, this it is which also generates the object. And this part of Soul it is which is the " nature " of each several object, being present alike in plants and in animals one and all, whereas the other parts of Soul, while present in some living things, are absent from others.

Now in plants the female is not separate from (o) why the the male ; in certain of the animals, however, it is '^^^Jf^ separate, and here, in addition, it has need of the generate male. And yet anyone might well raise the puzzle, y°°®" ex€t OLpyriv, and De caelo 301 b 17 <f>vais /xev iariv tj ev ainCo VTTapxovoa Kivi^aews apx'?* See also Introd. § 42. •* See Introd. § 43.


741 a

ARISTOTLE p-qaeiev av Stct rtV alriav. eiTrep ^y^ec to dijXv rrjv avTrjV fjjvx^v /cat 7^ vXrj ro TrepiTTCOjU-a to tov drjXeos icTL, tl TrpoaheiTai, tov dppevos, dAA' ovk avTO i^ avTov yevva to drjXv; aiTLov 8' on 10 oLa<f)€p€t TO l^ipov TOV <^VTOv alod'qaei' dSvvaTOV Be TTpoaojTTov rj X^^P^ V '^^RK^ elvai tj dX\o rt fxopiov jXT] evovarjs aladr]TLKrjs ^VXV^> V ^vepyeia T) hvvdp.€L, Kal tJ tttj t) a.TrAojs'- earat yap olov vcKpos 'q V€Kpov fxopiov. el ovv to dppev cgtI to TTJs TOLavTr]£ TTOiiqTLKOv ipv^T]?, 07T0V /<:e;^6(jptCTTat 15 TO drjXv Kal to dppev, dSvvaTOV to drjXv avTO e^ avTOV yevvdv t,cpov to yap elprjixevov -^v to dppevO' etvaf eTTcl otl y* e;)^et Xoyov rj Xex^^lfyo. drropLa, (f>avep6v enl tojv opvWcov tcov ret virr^vepaa tlktovTwv, OTL hvvaTai fte'xpt ye tivos to drjXv yevvdv. eTL S' e^et Kal tovto diropiav, ttcos tl? avTOJV ra 20 a»a <j>ria€i ^ijv. ovt€ yap ovtcos d>s Ta yovLjxa (pa evhex^Tat [eyiyveTO yap av i^ avTcbv evepyeLa ejJLifjvxov) ovd^ OVTCOS oiOTTep ^vXov ?} Xidos. eOTL yap Kal tovtojv tcov codiv (f)dopd tls cos [leTexovTCOv TpoTTOV TLvd l,corjs irpoTepov. SrjXov ovv otl e;^et TLvd SwafxeL i/jvxtjv. TToiav ovv TavTTjv; avayKiq 25 St) T'r]v eaxdTfjv. avTTj S' cotIv rj OpeTTTLKrj- avTT] ^ dppevi S : appev vulg.

° Cf. 732 a 13, n. * The production of sentient Soul.



to what cause this is due. Granted that the female possesses the same Soul (as the male) and that the residue pro\ided by the female is the material (for the fetation), why has the female any need of the male in addition ? ^^'hy does not the female accompUsh generation all by itself and from itself ? The reason is that there is a difference between animal and plant : the animal possesses sense-perception." It is impossible for any part of the body whatever (face, hand, flesh, etc.) to exist unless sentient Soul is present in it, whether in actuality or potentially, whether in some quahfied sense or Avithout quahfication. Other^^-ise what we have wiW be on a par with a dead body or a dead limb. Thus, if the male is the factor which produces the sentient Soul in cases where male and female are separate, it is impossible for the female all by itself and from itself to generate an animal ; because the faculty just mentioned * is the essence of what is meant by " male." Still, it is not at all unreasonable to raise the puzzle we have stated, as is sho^^â– Tl by the instance of those birds which lay wind-eggs : this proves that up to a point the female is able to generate. But there is a puzzle here too : In what sense are we to say that these eggs are ahve ? We cannot say that they are ahve in the same sense as fertile eggs, for in that case an actual living creature would hatch out from them ; nor are they on a par with wood and stone, because these eggs go bad just as fertile ones do, and this seems to indicate that to start with they were in some way ahve. Hence it is clear that potentially they possess Soul of a sort. What sort, then ? The lowest, it must be, ob\'iously ; and this is nutritive Soul, because this it is which is present 208




8td Tt ovv ovK aTToreAei to. fiopia /cat to ^wov; OTL Set alcrdrjTLKTjv avra ep^etv ifjvx'^^v' ov yap eariv ojGTTep (pvTOV TO. fxopia rGiv l,cpa)v. 8i6 Seirat rrjs Tov appevos KOLVOJVias' /cep^ajptarat yap iv tovtois 30 TO appev. birep /cat avfx^aa'eL- to. yap vrrrjvejXLa yLveTai yovLjJia, eav eV rivt Kaipco to appev eiro)(evar). dXXa TTcpl jxev Trjs toutcdv aiTias vaTepov 8iopiadr]aeTaL.

Et S ecTTt Ti yevos o OrjXv /xeV ioTLV, appev Se fXT) e)(ei KexojpLOjxevov, evhe)(eTaL tovto^ ^coov e^ avTov yevvdv. orrep d^LOTTLGTCos fxev ov avvcoTTTai, 3r^ jxexpt ye TOV vvv, TTOtec Se StCTra^etv {eVta)^ ev Ta> yevei to) tojv L)(dva>v tcov yap KaXovp,ev(x}v ipvOpLVCov dpprjv fjiev ovdeis coTTTai. ttco, drjXeiai 8e /cat KvrjixaTOJV TrXrjpets. dXXd TOVTa>v puev outtoj TreZpav e^opiev d^toTnuTov, ovTe he drjXea ovTe dppeva /cat 741 b ev TO) Tcov i)(dvcov yevet eoTiv, olov at r' iyx^Xeis Kal yevos Tt KeoTpeoiv Trepl tovs TeAjU-ariatous" ttoTapiovs. iv oaoLS Se Ke^o^pt'OTai to dT]Xv /cat to appev, dSvvaTov avTo /ca^' avTo to drjXv yevvdv ets ^ avev oxeias addit P. * <evta> Hackforth.

" See 750 b 3 if., 757 biff., also 730 a 5 ff . and H.A. 539 b 1.

  • " Probably some species of Serranus, perhaps S. anthias (a sea-perch). Cf. H.A. 538 a 21, 567 a 27. Actually the majority of species of Serranus are hermaphrodite (see E. S. Goodrich, Cyclostomes and Fishes, 430), as was discovered by Cavolini in the latter part of the 18th cent. See A.-W., Introduction, pp. 32 ff.

" i.e., roe.

"* Eels do not develop generative organs except in deep water, whither they go in order to breed. This is taken to 204


alike in all animals and plants. Why then does this Soul fail to bring the parts to their completion and so produce an animal r Because the parts of an animal are bound to possess sentient Soul, since they are not on a par with those of a plant ; and that is why the male is required to take its share in the business (the male being separate from the female in such animals). The facts bear this out : wind-eggs become fertile if the male treads the female within a certain period. However, the cause of these things >vill be fully determined later on.** If there is any class of animal which is female and has no separate male, it is possible that this generates offspring from itself. This has not so far been reUably obsened, it is true, but some instances in the class of fishes give cause to suspect that it may be the case. Thus, of the fish known as erythrinus * not a single male specimen has so far been observed, whereas female ones have been, full of fetations.*^ But although with regard to these we have no rehable proof so far, there are also in the class of fishes some which are neither male nor female : e.g., eels,** and one sort of cestreus * which frequents marshland rivers. In all animals, however, where the male and female are separate, the female is unable by itself to generate offspring indicate that they are descended from an original deej>water fish. See additional note, p. 565, ' This cannot be the grrey midlet {Mugil capita, Cuv.), but is probably a species of Muraena or Gymnotus. In P.A. ti9ti a 5, Aristotle speaks of a cestreus found in the lake at Siphae in Boeotia, on the south coast, near Thespiae (now Tipha). Cf. also the reference at 763 b 1 to Pyrrha, where there was a lagoon which was apparently one of Aristotle's favourite spots for studying animals.


741 b

ARISTOTLE reXog- ro yap appev [xdr-qv av rjv, rj Se (Jjvols ovSev 5 TTOieZ pLarrjv. hioTrep iv rolg tolovtoi? del to dppev CTTiTeAet TTjv yeveatv. e/X7rotet yap tovto rqv aiadrjTiKrjV ifjvxrjv, rj 8t' avrov t] Sio. rrjg yovrjs. evvTTap)(6vr(jL>v S' ev rrj vXr) SwdfieL tcov /xopicov, orav dp)(7] yevqrat Kivijaecos, wajrep iv rocs avrofiaroig davjJLaai, avveiperai to e^e^T^?* Kal o ^ov 10 XovraL Xeyeiv TLves tcov <f)vaiKcJjv, to " <f)ep€adai els TO ofjioiov," XeKTeov ovx d)9 tottov pbeTa^dXXovTa ra fjiopia KiveladaL, aAAa fzevovTa Kal dXXoi.oup,€va fxaXaKOTr^Ti Kal aKXrjpoTrjTL Kal ;)^pcu/xaCTt Kal Tats dXXats rats' tcov 6p.OLop.€pix)v Siacfiopals, ytvojjieva 15 ivepyeia a. VTrrjp)(ev ovTa hvvdpbet irpoTepov. ylyV€Tat 8e TTpaJTOv rj dp^ij- avTrj 8' cotIv tj Kaphia TOLS ivaipLois, Tolg 8' aAAot? to dvdXoyov, ojOTrep etprjTai TToAAa/cij. Kal tovto (f>av€p6v ov jjlovov /caro. TT^i' atadrjOLVy otl ytveTac TrpcoTOV, aAAa Kal TTepl TTjV TeXevTriv ctTroAetVet yap to t/qv IvTeWev 20 TeAeuratov, avfx^aLvei 8' €7tI TrdvTcov to TcXevTatov yivoijcevov^ TrpcjTov aTToXeiiTeiv , to Se TTpcoTOv TeXevTalov, uiortep Trjs (jivaecjs SLavXoSpofxovcrrjs xal ^ yevofievov P.

" i.e., the matter provided by the female.

  • See note on 734 b 10.

" <f>vGi,KOL, sometimes (f>vat.oX6yot, a term used by Aristotle to describe the early writers on <f)vms, i.e., nature, or the nature (stuff) of the universe and its contents. They include the so-called " early philosophers," and apparently also Hippocrates, as here (see note on 740 b 14). Several of the pre-Socratic philosophers had made use of this principle in various connexions. - See also pp. xvi f.

<« Cf. above, 740 b 14. ' See Introd. § 48.

f See App. B §§ 4-6, 9-10.



and bring it to completion : if it could, the existence of the male would have no purpose, and Nature does nothing which lacks purpose. Hence in such animals the male always completes the business of generation - it implants sentient Soul, either acting by itself directly or by means of semen. As the parts of the animal to be formed are present potentially in the matter," once the principle of movement has been supplied, one thing follows on after another without interruption, just as it does in the " miraculous " automatic puppets. ** And the meaning of the statement, made by some of the physiologers,-' about like " making its way to hke,"** must be taken to be not that the parts of the body " move " ^ in the sense of changing their position, but that while remaining in the same position they undergo " alteration " f as regards softness, hardness, colour, and the other differences which belong to the uniform parts ; that is, they become in actuality what previously all along they had been potentially. The first to be formed is the " principle," which in blooded animals is the heart and in the others the counterpart of the heart, as I have said many times over. There can be no doubt about this, because our senses tell us that it is the first thing fornied ; but the truth of it is confirmed by what happens when the creature dies : the heart is the place where life fails last of all ; and we find universally that what is the last to be formed is the first to fail, and the first to be formed is the last to fail.' It is as though Nature were a runner, covering a double course there and back, and retracing her » Cor primum vivens ultimiim morions : cf. Ebstein et at.. Mitt, zur Gesch. der Medizin nnd Naturw.' 19 (1920), 102, 219, 305.


ARISTOTLE • aveXiTTOiJLevrjs eiri rrjv dpx^v odev rjXdev. eari yap ■rj' fxkv yeveaig e/c rov fir] ovrog ets to 6v, rj 8e (poopa e/c Tov ovro? TraAtv els to firj 6v.

VI 25 Fiverat Se [xera tyjv apx^v, MOTrep iXexdf]> ^a evTos npoTepov twv cktos. ^aiVerat Se TrpoTepa ra {jieyedos e)(ovTa tcov iXaTTovcov, ovS^ eVta yiy vofxeva rrpoTepov. TrpcJjTov he to. avco SLapdpovTai TOV Sta^co/jiaTOS , Kal Sta^epet fieyedet,- to Se koltoj Kat eXaTTov /cat ahiopLOTOTepov . /cat tovto ylyve 30 rat ev Trdatv, ocroig to avio /cat to koltoj StcoptCTrat, TtXtjV €V TOiS ivTOjJiOLS' TOVTOJV 8' iv TOLS OKO)Xt)KO TOKOvjjLevoLg €771 TO avo) rj av^Tjcn? yiveTai- to yap avoj i^ vTrapxrjs eXaTTOv. dSiopLaTOV Se /cat TO dvoj /cat TO /carco rot? /LtaAa/ctoi? tcSv TTopevTiKcov fjiovois. TO Se XexOev au/x^atVet /cat eTTt roiv 35 <f)VTa)v, TO TTpoTepeZv ttj yeveaec to dvco kvtos tov KaTOidev ras" yap pit,as rrpoTepov d<j>tdaL to. airip fiaTa Tcbv TTTOpdiOV.

Atopt^erat Se to. jxepr] tcov ^cpcjv nvevpiaTi, ov jxevTOL ovTe to) Trjs yevvcoarjs ovtg to> avTov, " See 740 a 12 ff.

  • Aristotle's observations are quite correct. Cf. the theories of C. M. Child on axial gradients, physiological dominance {cf. Aristotle's own use of /cvpio?, 742 a 84 below), etc., conveniently discussed by J. Huxley and G. R. de Beer in ElementH of Experimental Embryology. See also 742 b 14.

â– ^ According to Aristotle {LA. 705 a 29 ff.), the distinction between the upper and lower portions of animals and plants is determined by function, and not by position relative to the earth and the sky. The " upper " portion is that from which is received the distribution of nourishment and material for growth : and the extremity towards which the nourishment arid growth penetrate is the " lower " extremity. Thus, as 208


steps towards the starting-point whence she set out. The process of formation, genesis, starts from notbeing and advances till it reaches being ; that of decay starts from being and goes back again till it reaches not-being.

After the " principle " is formed, the other parts VI are formed, the internal ones earlier than the exter- n|^^*(^f^{,h^ nal, as I have said." The larger parts become visible, embryo however, earlier than the smaller ones, although some ' '""^ ^ of them are not in fact formed earlier. First the parts above the diaphragm become articulated, and these are larger in size, whereas that which is below is smaller and less clearly defined.** This happens in all cases where the upper and the lower portions " are definite and distinct, except Insects : in those Insects which are produced as larvae, the increase occurs towards the upper part, as this is smaller to begin with. The only locomotive animals in which there is no definite distinction between the upper and lower portions are the Cephalopods.*^ What has been said here applies to plants as well : the formation of the upper portion precedes that of the lower : seeds send out their roots before their shoots.* Now the parts of animals are differentiated by means of pneuma f ; but this is not the pneuma of the mother, nor that of the creature itself, as some of he says (705 b 6), in plants, the roots are the " upper " portion, since it is through their roots that plants get their nourishment, just as animals do through the mouth. Cf. the end of the present paragraph, 741 b 34 flF . ; also the passage in P. A. 686 b 21 ff.

â– * Because (720 b 18, P. A. 684 b 15, 685 a 1) their backpart is drawn up on to the front-part, their tail-end is bent right over to meet the front, and in consequence the residual vent is brought close to the mouth.

• See note on 741 b 30. ' See App. B §§ 7 ff.


ARISTOTLE 742 a KadoLTrep rives rchv (fyvaiKtov (f>aaLV. (ftavepov 8e^ TOVTO €7n rix)v opvidojv Kal rcov Ixdviov Kal rwv evToficuv. ra p.ev yap -)(Ci}pL(jQivra ttjs yevvayarjs yiverai e^ (pov, iv a> Xajx^dveL rrjv Sidpdpcocnv rd 8' oAo)? OVK dvaTTveZ rcov i,cpajv, OKCoXrjKOTOKeLrai Se 5 Kai cporoKelrai' rd 8' dvanveovra Kal iv rfj pnqrpa Xafji^dvovra rrjv hidpOpcjaiv ovk dvanveL rrplv ri 6 TrXevjxcov Xd^rj reXos' SiapOpovrai Se Kal oSros Kal ra ejJiTTpocrdev pLopia nplv dva7TV€iv. eri, 8' oaa TroXvcrxiSr] rcov rerparroScov, olov kvcjv Xea)v Xvkos 10 aXojTTT]^ dcos, Trdvra rv^Xd yevva, Kal hilararat rd ^X€(f>apov yevofievcov varepov. coare SrjXov on rdv avrov rpoTTov Kal ev rotS" aAAoiS" Trdai, KaddTrep Kal ro TTOLov, Kal rd rroadv yiverac Swdfiet TTpovTTdp-)(ov, evepycLo. 8' varepov, vtto rdjv avrdjv aurCwv vcf) OJVTTep Kal rd ttolov Stopt'^erat, Kal yiyverai Suo e^ 15 evos. TTvevfia 8' VTrap)(^ei,v dvayKalov, on vypdv Kat depjxov, rov p.€v iroiovvros, rov 8e 7rda)(ovros .

Td)v 8' apxcuLCov rives <f)vaioX6ycov ri p-erd ri yiyverai rcov p,opiwv eTreipddrjcrav Xeyeiv, ov Xiav ep-veipiKcvs e)(ovres rcov avp,^aiv6vrcov . rdJv yap ^ Se P : yap vulg.

" See note on 741 b 10. e.g., Hippocrates, -n. ^u'ctio? naxhiov 17 (vii, 496-498 Littre) ij he. aap^ av^ojxevr] vtto tov TTvevjjLaTOS apdpovrai, Kal epxerai, iv aureji eKaarov to o^jmiov cus TO ofiOLOi' . . . hiapdpovrai vtto rijs TTVorjs eKaara, <^vaa)Hiva yap huararaL ^vfiTrayra Kara crvyyevfLav. Cf. also ch. 19. According to this treatise the embryo both received nourishment and breathed through the umbilicus (cf. chh. 13, 15).

    • Viz.', birds. " \'iz., fishes and insects.

•* Viz., Vivipara. 210


the physiologers " allege. This point is clear in the case of birds, fishes, and insects : thus, some ** of these are foniied out of an egg, after separation from the mother, and it is in the egg that they get their articulation ; and some animals *" do not breathe at all, but are produced as larvae or as eggs ; others,** which both breathe and get their articulation ^\â– ithin the uterus, do not however breathe until their lungs have reached completion : with them, both the lungs and the preceding parts become articulated before they breathe. Further, the polydactylous quadrupeds (such as the dog, the lion, the wolf, the fox and the jackal) all bring forth their young blind, and the eyelid does not separate until some -time after birth. Hence it is clear that, with regard to all the other parts as well, the same holds : just as the characteristics of quaUty are there potentiality to begin ^^ith and later on are formed in actuality, so too those of quantity are formed - by the same causes as those by which the characteristics of quality' are differentiated, and two things are formed out of a single one.^ As for pneuma, its presence is the result of necessity, because liquid substance and hot substance are present, one being active and the other being acted upon.^ Some of the early physiologers endeavoured to describe the oi-der in which the various parts are formed, but they were none too well acquainted with what actually happens. As with everything else, so ' e.g., two eyelids ; an example of a potential duality being actualized. - See also App. B § 7, n.

  •, the pneuma is not iireiaoKTov, but avfjuj>vTov, derived from within, and hence can serve as an " instrument " (see 789 b 3 ff. 1 charged with a specific *' movement " (see Introd. g 68, and App, B, esp. § 32).


742 a

ARISTOTLE yiopicov, (haTTcp Kal em rcov dXXcov, TTe(j>VKev krepov 20 erepov Trporepov. to 8e Trporepov TJSr) TioAAa^to? iariv. TO re yap ov eVe/ca /cat to tovtov eveKa SLa(f)€pei, Kal to [xev ttj yeveaei TrpoTepov avTOJV earl, ro §e rrj ovaia. hvo 8e hia(f)opas ^x^i' xat TO TOVTOV^ eveKa- to fiev yap eoTLV odev rj Ktvr^GLg, TO Se (L xprJTai to ov eveKa. Xeyoi 8' olov to re 25 yevvrjTLKOv Kal to opyavLKOv tco yevvojpbevcx)^' tovtcov yap TO fjiev VTrapxetv Set irpoTepov, to ttolt^tlkov, OLOV TO StStt^av'^ rod p,av6dvovros, rovs 8' avXovs varepov rov fiavOdvovros avXelv Treptepyov yap fir^ eTTiarapievoLS avXelv vTTdp)(^eiv avXovs. rpiiov o ovrcov, ivos fxev rov reXovs, o Xeyop^ev elvai ov eveKa, hevrepov 8e rwv rovrov eveKa Trjs o.pXV^ 30 rrjs KLVT]TLKrjg Kal yevvrjTLKrjs (to yap 7roL7]TLKov Kal yevvrjTiKOV, fj Toiavra, Tipog to TTocovfxevov iari Kal yevva)[ievov) , Tpirov 8e tov â– )(^prjaLiiov /cat c5 ;i^/37yTat to reXos, TTpcoTov fxev vrrapx^i-v dvayKalov â– ft iJLopLOV ev a) r) dp^r] Trjs KLvrjaecos {Kal yap evdvs TovTo* fiopiov iaTL tov reXovs ev Kat kv 35 ptcoTarov) , eTretra /zera tovto to oXov Kal to reXog, TpLTOv 8e Kal TeXevTalov rd opyaviKa tovtovs p^^pf] TTpos evtas XPV^^'-^- ^^'^^ ^'^ '^^ tolovtov eariv, 1 TOVTOV PS : ov vulg.

^ yevvcofievw 7i : yevofjievu) Vulg.

^ StSa^ov Richards.

  • fort. TOVTO TO (Z^*) scribendum, et mox ev<€Ka>.

« Cf. Met. 1035 b 18 ff.

" This will be niodifted in a moment, when Aristotle subdivides this heading. Some of the things which are for the sake of the End are posterior to it in point of formation.

"^ By this, as appears from 742 b 13, 1 4 below, is meant the " upper portion," the head and trunk. 212


with the parts of the body : one is, by nature, prior to another." But the term " prior " at once comprises a variety of meanings. E.g., take the difference between {a) that for the sake of rvhich a thing is, and (b) that thing which is for its sake : of these, one (6) is prior in point of formation, while the other (a) is prior in point of being or reaUty. Further, " that which is for the sake of the End " comprises two divisions : (i) that whence the movement is derived and (ii) that which is employed by the End ; or, in other words, (i) something which generates, and (ii) something which serves as an instrument for what is generated. Of the two, the productive factor must exist prior to the other : e.g., a teacher must exist prior to a learner, while pipes are posterior to the person who is learning to play them : it is superfluous for people who cannot play pipes to possess them. So we have these three things : (1) the End, which we describe as being that for the sake of rvhich (other things are) ; (2) the things which are for the sake of the End, .\\z., the activating and generative principle (second, because the existence of that which is productive and generative, qua such, is relative to what it produces and generates) ; (3) the things which are serviceable, which can be and are employed by the End. Thus, first of all there must of necessity exist some part in which the principle of movement resides (for of course this is a part of the End, and the supreme controlling part of it) ; after that comes the animal as a whole, i.e., the End '^ ; third and last of all come the parts which serve these ^ as instruments for various employments. If it is true, then, that there is a part

    • Or perhaps " this," referring only to the " End."


ARISTOTLE 742 b orrep avayKoiov vrrapxecv iv rotg iC,cpois, to TTdarjg exov TTJs (f>va€a)s o.px^v /cat reXog, rovro yiveadai TTpcbrov avayKaZov, fj jxev klvtjtlkov, Trpcorov, fj 8e jxopLOv Tov reXovs, iiera. rod oXov. ware tcov fxopiojv Tcbv opyaviKwv oaa ycev ecm yevvrjTLKa rrjv 5 (f)vaLV, act irporepov Set VTrapxeiv avrd [dXXov yap eveKo. ioTiv co?^ apxr}), oaa Se (jltj roiavra tcov aXXov eve/ca, voTepov. hio ov paSiov SteAeiv rrorepa TtpoTepa TCOV fjioploiv, oaa aXXov evcKa, -^ ov^ evcKa TaVTa. 7rap€IX7TL7TT€t yap to. KLVT^TLKO. tcov {XOpLCOV TrpoTepov ovTa rfj yeveaei tov tcXovs, to. 8e klvtj10 TiKct 77/30? TO, opyaviKa hieXeZv ov pcihiov. /cairoi Kara favTrjv ttjv piidohov Set t^rjTelv tL ytVerat juera Tt' TO yap TcXos ivLCov pev voTepov, evicov Se irpoTcpov. /cat Sta tovto TrpaJTOv pev to k^ov ttjv dpXTjV yiVerat popiov, eir' i^op^vov to dvco kvtos. Sio rd TTepl TTjv Ket^aXrjV /cat Ta oppara peyioTa 15 /car' dpxds ^atVerai rols ip^pvois, rd Se /caroj tov op(f)aXov, otov Ta KcbXa, piKpd' tov ydp dvcD TO. /carcD eVe/cer, /cat ovt€ popia tov TeXovs ovt€ yeivrjTLKd avTOV.

Ov /caAtDs" Se Xeyovatv ovhe tov Sta tl t7]V ^ CO? P : d>s-q vulg. " oi?] c5v P.

" i.e., generative of other parts, as the heart is.

'â– Or, reading r] apxq, "just as the first principle is for the sake of the End." 214


of this kind - a part which contains the first principle nd the End of the animal's whole nature - which uust of necessity be present in an animal, then this part must of necessity be formed first of all - formed first, qua activating, though formed along vrith the whole creature, qua being a part of the End. Thus, those instrumental parts which are in their nature generative ° must always be there themselves prior to the rest, because they axe. for the sake q/" something else, as being a first principle ** ; those parts which, although they are for the sake 0/ something else, are not generative, come later. That is why it is not easy to determine whether those parts are " prior " which are /or the sake of something else, or that part Jbr nhose sake these others are present. The activating parts intrude themselves into the picture, because in formation they are prior to the End ; and it is not easy to determine as between the activating and the instrumental parts. Still, this is the Une we must follow in trying to find out the order in which they are foi-med ; for the End, though it comes after some of them, is prior to others. And on this account the part which contains the first principle is the first to be formed ; then follows the upper portion of the body ; and that is why in embryos we see that the parts round the head and eyes are the largest at the outset, while the parts below the umbiUcus, for instance the legs, are small. The reason is that the lower portions are for the sake of the upper portion, and they are not parts of the End "^ nor are they concerned in generating it.

People who say, like Democritus of Abdera, that

  • See above, 743 a 35, 713 b 13, H. They are merely useful adjuncts, enabling it to move about, etc.


742 b

ARISTOTLE avayKTjv, oaoi Xeyovaiv on ovtcos del yiverai, Kal 20 ravTTjv eivat, vofxi^ovaiv dipxyjv ev avrots, (Larrep ^■qixoKpiTOS 6 ^ AfihrjplTrjs , on rov fiev [del Kal]^ aneipov ovk eanv dpxrj, to he hid ri dp^rj, rd 8' aet aTTeipov, oiore to epcoTav to hid tl rrepl T<Jbv TOLovTwv TLvds TO ^rjTeLV elvai (jirjcrt tov direlpov apxTjV. KaLTOL Kara tovtov tov \6yov, Kad^ ov 25 d^iovcrt to hid tL /lit) ^rjTelv, ovdevos aTTohei^is ecrrat tojv dihicov ^atVerai 8' ovcra ttoXXcov, t<1>v {xev yLvofJLevcov del tojv 8' ovtcdv, errel /cat to Tpiycovov ^x^t-v hvalv opdals taas del Kal to tt^v htajxeTpov dcrupipieTpov elvai rrpos ttjv vXevpdv dthiov, aAA' ojxco? eanv avTcov wltiov tl Kal drro30 hei^LS. TO fJiev ovv fir] ttovtcov d^iovv t,rjr€iv dpx^jv XeyeTai KaXco^, to he tcov ovtwv del Kal ytvofxevajv rravTCDV ov KaXw?, dAA' ocrat Tcijv duhtajv dpxo-l Tvyxdvovatv ovcrar ttjs ydp dpx'rj? dXXr] yviooLS Kal OVK drroheL^is . dpxrj 8' iv fiev Tolg dKivqTOis to 1 seel, Platt.

" Cf. Met. 1011 a 13 aTroSetfew? yap apx^j ovk aTToSei^ls eoTiv. Also Anal, Post. 90 b 34 ff. at a.px'i^ twv d-rroSei^ecDv opia^oi, cov oTi OVK eaovrai aTTobei^as SeSet/crai Trporepov fj eaovrai, ai apxal (XTroSeiKTat koL Toir dpxoJv apxai . . . opta/xo? /xev ydp tov tl ioTi kol ovaias. See also 72 b 20 if. ; also Met. 1013 a 15 (one of the definitions of dpxTj) ert odev yvcooTOV TO â– npdyfia TrpwTov, /cat avrr) dpx^ XeyeTai tov npay HaTOS, olov tG)V dTTobei^ecov ai vnodeaeis. In Eth. N. 1142 a 26 it is said to be " intelligence " (vovs) which apprehends definitions that cannot be proved by reasoning. Aristotle also speaks there of " the sort of intuition " (aladrjais) where 216


" this is how they are always formed," and regard this as a starting-point (first principle) in these cases, make a mistake, nor do they even succeed in stating tlie necessity involved in the cause. Their argument is this : What is limitless has no starting-point ; but the cause is a starting-point, and what is always is limitless ; therefore (says Democritus) to ask for a cause in connexion with an}i:hing of this kind {sc, anything that ahrays is) is the same as trying to discover a starting-point in something that is limitless. Yet on this line of argument, on the strength of which they undertake to dispense with trying to discover the cause, there will be no demonstration of any single one of the " eternal " things. It is obvious, however, that demonstrations of many of these (some of them things which ahvays come to be, some things which always are) do in fact exist. For instance, the angles of a triangle are always equal to two right angles, and the diagonal of a square is always incommensurable with the side ; in both of these cases we have something " eternal," yet there is a cause for them and they are demonstrable. Thus it is right to say that we cannot undertake to try to discover a startingpoint (a first principle) in all things and evervthing ; but it is not right to deny the possibihty in the case of all the things that always are and that always come to be ; it is impossible only vvith the first principles of the eternal things, for of course the first principle does not admit of demonstration, but is apprehended by another mode of cognition." Now with those things that are " immutable," the first principle is hy we perceive that the tiltimate figure in mathematics is a triangle. Again (114.3 b 1) in demonstrations, voO? apprehends the immutable {aKivrfra) and primary definitions.



742 b

TL eoTLV, iv 8e rot? ytvofievots yjSr] irXeiovs, Tporrov 35 6 aAAov /cat ov Trdaai rov avrov Sv fxla tov aptdfiov, odev rj klv7]ol? eariv. Sto TrdvTa ra kvaifxa Kaphiav ex^i rrpaJrov, coanep iXexdr] Kar^ o-px^-S' €V Se Tols dXXots to dvdXoyov yiverat, rfj 743 a Kaphia Trpcorov.

E/c Se rrjs KapStas at ^Xi^es SiareTavrai^ KadajTep OL Tovs Kavd^ovs ypd^ovTes iv tols toixols' Ta yap p-eprj nepl TavTag iaTLv, aTe yivopueva e/c TOVTOJv. 7) 8e yevecris eoTiv [e/c]^ tcjv o/xoto5 [xepoJv V7TO ipv^ecos /cat d€pp.6Tr]TOS' ovviaTaTai yap /cat TTijyvvTai Ta [xev ipvxpcp ra 8e depfio). Trepl Se Trjg tovtcov Sia^opds eLprjrai nporepov iv erepot?, 77"ota Xvtcl vypo) /cat TTvpi, /cat TTOta aXvTa vypo) /cat aTTjKTa nvpL Sid puev ouv tcov (jyXe^cov /cat Ta)V iv CKdaTois TTopcov hiaTnhvovaa rj Tpoffjrj, 10 Kaddnep iv tols o>pLOLS K^papbioLS to vScxjp, yivovTaL ^ Peck : Siarerafidvai vulg. " om. SS, Platt : -q coni. A.-W.

" The term "immutable" is often used by Aristotle in connexion with mathematics, as here. - " Essence," lit., " the ' what is it?'," the essential definition or nature of the thing. Cf. quotation from Anal. Post, in preceding note, and Phys. 198 a 16 f. "in the case of the immutable things, e.g., in mathematics, where ultimately all is referred back to definitions, TO Std Tt (' why ') is referred back to to ti eori (' what,' the essence of the thing)." The essence is directly perceived, not demonstrated. (See previous note.)

  • " This is one of the definitions given in Met. 1013 a 4^ that from which, being present within it, a thing first comes into being {odev rrpcuTov ylyveTaL ivvTrdpxovTos).

' He has repeated it almost continuously.



the essence " ; but as soon as we begin to deal with those things that come into being through a process of formation, we find there are several first principles - principles, however, of a different kind and not all of the same kind. Among them the source whence the movement comes ^ must be reckoned as one, and that is why the heart is the first part which all blooded animals have, as I said at the beginning <^ ; in the other animals it is the counterpart of the heart that is formed first.

Beginning at the heart, the blood-vessels extend all over the body. They may be compared to the skeleton models which are traced out on the walls of buildings,"^ since the parts are situated around the blood-vessels, because they are formed out of them. The formation of the uniform parts is effected by the The agency of cooling and heat ; some things are " set " ^r^â„¢ and solidified by the cold and some by the hot. I have spoken previously elsewhere " of the difference between these, and I have stated what sort of things are dissoluble by fluid and by fire, and what sorts are not dissoluble by fluid and cannot be melted by fire. Resuming then : As the nourishment oozes through the blood-vessels and the passages in the several parts (just as water does when it stands in unbaked â– * Cf. H.A. 5l5a.Sa. Hesychius's and Photius's definitions of Kttva/Soi describe them as the woodwork around which modellers, when they begin their modelling, mould the wax or plaster. There is a similar passage in Parts of A n imals, though without mention of this term (654. b •29) ; there Aristotle speaks of a " hard and solid core or foundation " round which the figure is modelled ; though in that case he is speaking of the bones. There seems to be no justification for interpreting KovajSoi as a mere outline or sketch ; nor would such a meaning fit the passage. Cf. 764. b .SI.

' Meteorologica, Bk. IV, chh. 7-10. Cf. also 762 a 31.


743 a

ARISTOTLE adpKe? rj to ravrais dvdXoyov, vtto tov ipvxpov GwiaTO-ixevai, Sio /cat Xvovrat vtto rrvpog. oaa 8e yerjpd Xiav rwv dvareXXoi'TCOv , oXcyTjv e^ovra vypoTTjra /cat deppiorrjra, ravra he ijjvxoixeva e^ar/Litt,ovTOS TOV vypov /xera tov depfiov ytVerat OKXiqpd 15 /cat yecohrj ttjv jXop(f)rjV, olov ovv^^s /cat KepaTa /cat oTrAai /cat pvyxV ^^ /MaAarTerat /xev TTvpi, T'^KeTai S' ovdev, aAA' ep'ta rot? vypots, olov to. KcXvcfyr] Tcbv cpajv.

'Ytto 8e TTys" ei^TO? deppiOTriTos ra re vevpa /cat TO, ocTTa yiVerat, ^rjpaivoixevrjs ttj? vypoT-qTO? . Sto /cat dAuTct ecrrt to. dcrra ?5Tro tow mvpos, Kaddirep 20 Kepafxos' olov yap ev Kapbivcp, (VTTTTjixeva cgtIv^ vtto Trjs iv TTJ yeveuei OepjjLOTriTog. avTrj oe ovre o tl eTV)(^ TTotet adpKa rj ootovv, ovd^ ottov^ eTV)(ev, ovd' oTTOTe €TVx^v,^ dXXd TO 7Te(f)VK6s /cat ov^ TTe^vKe /cat OTE 7T€(f)VKeV. OVT€ ydp TO SwdfJiCL OV VTTO TOV flTJ TTjv evepyeiav e^ovTOS KivrjTiKov ecrrat, ovt€ to ttjv 25 evepyeiav €XOV TTOfqaeL e/c tov tvxovtos , ojOTTep ovTe KL^ojTov fXYj €K ^vXov 6 TeKTCiiv TTOLTjaeLcv av, OVT* dvev TOVTOV /cijSojTos" ecrrat e/c tcov ^vXcdv. 'H 8e depfxoTTjs ivvTTdpx^L ev Tip CTTrep/xaTt/co) TreptTTcu/xart ToaavT7]v /cat TOLavTTjv exovaa ttjv Kivqaiv /cat tt]v evepyetav, oarj avfifieTpog et? eKaarov tcov [xopLCov. Kad' oaov o dv eXXeLTTT) 30 •^ vvep^dXXr], r) ;^erpov aTToreAet r) dvaTTrjpov to yivofxevov, TTapaTrXrjaiCOS rot? e^cu avvtaTafxevoLS ^ ecrrlv P : oni. vulg. ^ ottoi; P : otttj vulg.

ouS' OTTOTe CTuxev P : om- vulg. * o5 P : ^ vulg.



earthenware), flesh, or its counterpart, is formed : it is the cold which " sets " the flesh, and that is why fire dissolves it. As the nourishment wells up, the excessively earthy stuff in it, which contains but little fluidity and heat, becomes cooled while the fluid is evaporating together with the hot substance, and is formed into parts that are hard and earthy in appearance, e.g., nails, horns, hoofs and bills ; hence, these Nails, etc. can be softened, but not one of them can be melted, by fire ; though some, e.g., eggshell, can be melted by fluids.

The sinews and bones are formed, as the fluidity sinews and sohdifies, by the agency of the internal heat ; hence <>°*^bones (like earthenware) cannot be dissolved by fire ; they have been baked as it were in an oven bv the heat present at their formation. This heat, however, to produce fleshy or bone, does not work on some casual material in some casual place at some casual time ; material, place and time must be those ordained by Nature : that which is potentially will not be brought into being by a motive agent which lacks the appropriate actuality ; so, equally, that which possesses the actuality will not produce the article out of any casual material. No more could a carpenter produce a chest out of an\i:hing but wood ; and, equally, without the carpenter no chest will be produced out of the wood.

This heat resides in the seminal residue, and the movement and the activity which it possesses are in amount and character correctly proportioned to suit each several part. If they are at all deficient or excessive, to that extent they cause the forming product to be inferior or deformed. The same is true of things that are " set " by heat elsewhere than in 221


743 a

Sta rrjs ei/j-qcrewg Trpos Tpo(f>rjs drroXavaLv rj riva dXXrjv ipyaatav. dAA' ivravda fxev i^juet? t7jv ttjs depjXOTrjTos avfifxerpiav els rrjv KLvrjaiv irapaaKevd^ofiev, e/cet 8e StScoaiv 'q (f>VGLs r] rov yevvcovros.

35 Tols Se avropLaTCjos yivofxevoig rj ri]S copag atria KivrjaLS Kal 6epp.6rr]s.

'H 8e ijjv^is areprjais OepjJLoritjrog eariv. ;^p7^Tat 8' dpL(f>oTepoLS rj (j)vais e)^ovaL [xev SvvafXLV i^ 743 b dvdyKrjs ware ro fiev roBl to 8e roSt 770ietv, iv pievTOL TOLS yivopicvoLs evGKd TLvos (jvpL^aivei to piev ipv)(ecv avrcbv to 8e deppbaiveiv, /cat yiveadai Ttov piopicov eKaoTOv, ttjv piev adpKa pLaXaKr)v ttj piev e^ dvdyKTjs ttolovvtojv roiavTrjv rfj 8' eveKd 5 Tivos, TO 8e vevpov ivpov /cat eA/crdv, to 8' octtovv ^Tjpov /cat dpavarov. to 8e Seppia ^r)paLvopievr]s rrjs aapKos ytverat, Kaddrrep cTTt rot? eifjrjpiaaiv rj KaXovpevr) ypavs. ov piovov 8e Sta to ea^aTov avpi^aiveL avTov rj yiveais, aXXd /cat 8tOTt emTToXdt^ei TO yXiaxpov Sta to pirj Svvaadai e^,eiv.

10 ev piev ovv toIs aAAot? av)(^pirjp6v to yXiaxpov (8to ooTpaKoBeppia /cat piaXaKoorpaKa rd eaj^ard ecrrt TcDv dvalpicov t,a)cov), ev he rots evaipiOLS to yXiaXpov Xi7Tap(jL)Tep6v eoTiv. /cat tovtcdv oaa pir) yechhrj Tr]v (f)V(TLv ex€L Xiav, ddpoi^eTai, to TrtjueAajSe? vtto TTJV Tov SeppiaTos aKerrrjv, co? tov Sep/xaros" yt 15 vopievov e/c T-fjs TOiavTrjs yXiaxpdrrjTOS' e^^L ydp TLva yXioxpoTrjTa to Xtrrapov. rrdvTa 8e raura, Kaddrrep elrropev, XeKTeov yiveadai Trj piev e^ dvdyKrjs rrj 8' ovk i^ dvdyKrjs aAA' eveKo, tlvos.

« Cf. 767 a 17 if, i.e., the change required to be eifected ; see Introd. § 48, KivTjais. ' See Introd. § 8.



the uterus ; e.^., things which we boil to make them pleasant for food, or for any other practical purpose. The only difference is that in this case the correct proportion of heat" to suit the movement ** is supplied by us, whereas in the other, it is supplied by the nature of the generating parent. With those animals that are formed spontaneously the cause responsible is the movement and heat o^the climatic conditions. Heat and cooling (which is deprivation of heat) are both employed by Nature. Each has the faculty, grounded in necessity, of making one thing into this and another thing into that ; but in the case of the forming of the embryo it is for a purpose that their power of heating and cooHng is exerted and that each of the parts is formed, flesh being made soft - as Flesh, heating and cooling make it such, partly owing to necessity, partly ybr a purpose, - sinew soUd and elastic, bone solid and brittle. Skin is formed as the flesh skin. solidifies, just as scum or " mother " forms on boiled hquids. Its formation is due not merely to its being on the outside, but also to the fact that glutinous substance remains on the surface because it cannot evaporate. In blooded animals the glutinous substance is more fatty than in bloodless ones, in which it is dry, and on this account the outer parts of the latter are testaceous or crustaceous. In those blooded animals whose nature is not excessively earthy, the fat collects under the protective covering, the skin, which seems to indicate that the skin is formed out of this sort of glutinous substance, since of course grease is to some extent glutinous. We are to say, then, as already stated, that all these things are formed partly as a result of necessity, partly also not of necessity but ybr a purpose. '^ 223


743 b

IlpwTov jjiev ovv TO avu) Kvro? a(j>opit,eTai Kara rrjv yeveaiv, to 8e koltm Trpo'CovTos tov )^p6vov 20 XapL^avei ttjv av^rjaiv ev toZs eVat/xoi?. dnavTa he Tals 7T€pLypa(f>ais hiopit^eTai TrpoTepov, voTepov 8e Aafi^dv€L TO. ^(pojpLaTa /cat tcls ftaAa/coTT^ras" kol Tas aKXrjpoTTjTas , aTexv^JS oiorrep dv vtto l^ojypdcfiov TTJs (f>va€0}s 8rjpLovpyovp,€va- Kal yap ol ypa<f)eZs V7ToypdipavT€S Tats ypap,[j,als ovtojs iuaXetcfiovaL 25 TOt? XpwpLaai to t^cpov.

Ata pi.ev ovv to ttjv dp^^jv iv ttj KapSta tcov atadrjaecov etvac Kal tov ^coov uavTOS avTT) yiVerai TTpdJTov Sta 8e 7-57^ OepfxoTTjTa ttjv TavT-qg, fj TeXevrdJaiv at cjiXe^es dva>, to ifjvxpov avvtaTTjatv avTLaTpo(f)ov ttj depixoTrjTL ttj rrepi ttjv KaphLav tov 30 eyKecpaXov. hcoTrep Ta Trepl ttjv Ke(f)aXr]v Xapi^dvei avvexyj Tr]v yevccnv pLerd ttjv Kaphiav, kol pbeyedet rdjv dXXcov Sia(f)€p€f ttoXvs yap Kal vypos e^ dpx^js 6 €yK€(f)aXos.

"E;^et S' dTToplav to Trepl tovs o^daXpiovs avp.^alvov Tcov t^cpQJv. /xeytCTTOt pev yap e^ dpxrjs (j>aivovTaL Kal nel^OLS Kal ttXwtols Kal tttt^vols, 35 TeAeuraiot Se yivovTai twv popiayv iv to) peTa^v ydp xpovcp avp,7TL7TTOvaLV. a'lTiov S' oti to tcov 6(f)daXpd)v aladrjTrjpiov earl pev, oiairep koX rd dXXa atCT^r^TTypta/ IttI rropoiv aAAo. to pev tt^s- d(/)rjs 744 a Kal yevaecog evOvg ioTiv 7) acbpa rj tov croopaTos TL TCOV ^cpwv, rj 8' 6acf)p7jaLS Kat rj dKorj Tropoi (TwaTTTOVTes Trpos TOV depa tov dvpadev, nXrjpei? avp(/)VTOV TTvevpaTog , TrepaivovTes Se rrpos rd ^ a>aTT€p . . . aladrjrrjpia fort, secludenda ; suspic. est Platt. /u.€(' ioTiv Z })l'0 effTt fxiv ; TroAAa P pro to. aXXa.



Now the upper portion of the body is the first to be marked off in the course of the embrjo's formation; the lower portion receives its gro^\i:h as time o^oes on. (This applies to the blooded animals.) In the early stages the parts are all traced out in outline ; later on they get their various colours and softnesses and hardnesses, for all the world as if a painter were at work on them, the painter being Nature. Painters, as we know, first of all sketch in " the figure of the animal in outline, and after that go on to apply the colours.

As the source of the sensations is in the heart, the heart is the first part of the whole animal to be formed ; and, on account of the heat of the heart, and to pro%ide a corrective to it, the cold causes the brain to " set," where the blood-vessels terminate above. That is whv the regions around the head Brain, begin to form immediately after the heart and are bigger than the other parts, the brain being large and fluid from the outset.

The development of the eyes is something of a Eyes, puzzle to the student. In birds, beasts, and fishes alike, the eyes are from the outset ver}" large in appearance, yet they are the last of all the parts to be completely formed, since they shrink up in the meantime.*' The reason is that the sense-organ of the eyes is indeed, like the other sense-organs, set upon passages ; but whereas the sense-organ of touch and of taste is just the animal's body or some portion of the body, and smell and hearing are passages full of connate pneuma,'^ connecting \nth the outer air and terminating at the small blood-vessels around ' Cf. note, 740 a 28. » C/. H.A. 561 « 19 ff.

' See App. B §§ 26 ff.

1 225

744 a

ARISTOTLE (fyXe^ia tol Trepl rov €yK€<f)aXov reivovra cltto Trjg 5 Kap^ias' 6 8' o^^aA/ios" (Tcbfjia fiovov thiov e^^t twv aladrjriqpiaiv . ean S' vypov Kal ijjvxpov, /cat ov 7Tpov7Tdp)(ov iv TO) TOTTCv KaddiTep /cat rd dXXa IxopLa Swapuei, eTreira eve py eta yivop^eva varepov dAA aTTo rrjs Trepl rov eyKe^aXov vyporrjros aTTO 10 Kpiverai rd Kadapcorarov 8ia rwv iropajv ot <f>aivovrai (j)epovres avr avrwv Trpds rrjv jX'qvLyya rrfv Trepl rov eyK€(f)aXov. rovrov Se reKpirjpiov ovre yap dXXo piopiov vypdv Kal ilivxpdv eanv ev rfj Ke(f>aXfj Tiapd rov eyKecf)aXov, rd r d\i\x.a ipv^pdv Kal vypdv. e^ dvdyK7]s ovv d rdrtos Xapb^dvei 15 fJLeyedos rd Trpcorov, avpLTTLTTrei 8' varepov. Kal ydp TTepi rov eyK€(f)aXov cru/x^atVei rdv avrov rpdTTOV rd TTpdorov vypds Kal ttoXvs, aTTOTTveovros 8e Kat TTerrofxevov aoifxarovrai re fxaXXov /cat avpiTTLTTret, Kal d eyKe<j)aXos [/cat rd crcij/zara]^ Kat rd jxeyeOos rd rdJv dp.ixdra>v. e^ apx'TJS 8e Sta p.ev rov 20 eyK€(f)aXov rj Ke^aXrj fieytarrj, 8ta Se rd vypdv rd ev rots opLpiaaLV ol d(f>daXpiol fxeydXoi (jiaivovrai. reXevraloL he Xajx^dvovaL reXos hid rd Kal rdv eyK€(f)aXov avviaraadai jxdXts' dipe ydp Trauerai Trjs tpvxpdrrjros Kal rrj? vypdrnqros enl vdvrwv ^lev rdJv exdvroiv,^ p^dXiara 8' errl rojv dvdpcoTraiv. 8ia ydp 25 rovro /cat ro ^peyfia rtdv darcvv yiverai reXevratov rjhr] ydp yeyevrip.eva)v Ovpa^e rcbv ifx^pvcov ^ om. S, seclusit Rekker : Kal to. ofifiara Platt, om. Kal to IJ-eyedos to tu>v OfXfiaTcov.

  • TMv exovTojv P : habentibus magnum cerebrum S : om. vulg.



the brain which extend thither from the heart, the eye, by way of contrast, is the only one of the sense-organs which has a special " body " of its own. It is fluid and cold ; and, unlike the other parts, which are present in their places potentially to begin with and later on come to be formed in actuality, this one is not there at the start,*^ but it is produced by the purest part of the liquid around the brain being secreted off through those passages ^ which are to be observed leading from the eyes to the membrane around the brain. A sure sign of this is that beside the brain there is no part in the head except the eye which is cold and fluid. Hence it is due to necessity that this region gets large at first but shrinks later on ; because the same happens to the brain : at first this is fluid and large, but as evaporation and concoction proceed it becomes more solid and shrinks ; so does the size of the eyes. From the outset the head is very large, on account of the brain, and the eyes, as we see, are large on account of the fluid in them. But the eyes are the last of all to reach their completion, because the brain (on which they depend) does not " set " at all easily ; it is quite late before it ceases to be so cold and fluid ; and this is true of all animals that have a brain, especially of man. That is why the bregma '^ is the last of the bones to be formed : even after the embryos are brought to birth, this ° Aristotle's knowledge that the eye is an offshoot from the brain, and does not originate in the position which it finally occupies, is indeed remarkable.

' These are no doubt the optic nerves.

\ Cf. P.A. 653 a 34 and H.A. 491 a 31. This is the bone which finally grows over the space at the top of the skull known as the " anterior fontanelle." 227


744 a

fxaXaKov eCTTi tovto to ogtovv tols TraiStoiS'.^ o.'ltlov 8e Tov jxaXiOT^ eTrl roJv dvdpcoTTOJV tovto avfi^aLveLv, otl tov eyKe^aXov vypoTaTov e)(ovai /cat TrAetarov tcov t^cocxjv, tovtov 8' atriov otl /cat 30 Tr)v ev ttj Kaphia depfioTTjTa KadapojTGLTrjv . StjXol oe TTjv evKpaalav rj Stap-ota* (^povcficoTaTOV yap eoTL TCOV t,a)Oiv avdpcoTTOs. aKpaTrj 8e /cat to, TratSta fie^pt rroppoj ttj^ Ke(f)aXrjs ecrrt Std to jSapo? TO 7T€pl TOV iyK€(J)aXov. oixoLCos 8e /cat TcDv fJLopiojv ocra Set /civett i^ yap ^^/^X^ "^^ KLvrjaecDs 6i/je KpaTeX Ttuv dvcodev /cat TeAeu 35 TOiov, oacxiv r] KivrjaLS purj avvrjpTrjTai Trpos avT7]V, OJOTTep Tibv KCoXoJV. TOiOVTOV S' CCTTt fXOpLOV TO ^Xe(f)apov. inel 8' ovdev rroiel TrepUpyov ovSe fjLaTrjv 'q (f)vais, Si]Xov co? oi)S' VGTepov ovSe TrpoTepov CCTTat yap to yeyovos rf fjLdrqv t] TrepUpyov. 744 b a)ad d[x avdyKT] to. ^Xe^apa hLa^copit,€adai t^ KoX Svvaadai Kivelv. oipe fiev ovv 8ta to ttXtjOos TTJs 7T€pl TOV €yKe(f)aXov TTeipecog TeAetouTat to. o/x/xaTa ToTs ^cpocg, TeXevTCua 8e 8ta to G(f)6Spa KpaTova7]s TTJs Kiviqaeois elvat to Kivelv /cat to. 5 OVTW5 TToppco TTJs o-px^js Kal dTTeifjvypieva tG)v fxoplajv. SrjXol 8e to, ^Ae^apa TOiavT7]v exovTa ttjv (jivacv dv yap Kal ottooovovv ^dpos yevrjTai irepl TTjv K€(/)aXr}v 8t' VTTVov t) pbedrfv rj d'AAo Tt tojv TOLOVTCDV, ov Swdfjieda Ta jSAe^apa alpeiv, ovtoj ^dpos avTOJV i)(6vTa)v puiKpov.

^ Tots TraiSt'oi? P : tcDv rraiSiajv vulg. ^ â– ^ P : om. vulg. ^ re PS : om. vulg.

" evKpaaia. For Kpdms see Introd. § 40; and cf. P. A, 673 b 26 and Hippocrates, tt. SiaiTTjs I. 35. * See Introd. §§ 11, .51.



bone is still soft in the case of children. The reason why this occurs especially in man is that in man the brain is more fluid and greater in volume than in any other animal, and the reason of this, in its turn, is that the heat in the heart is purest in man. The fineness of the blend " in man is shown by his possession of intellect : there is no other animal which is so intelligent. Even children however for a considerable period lack full control over their heads. This is due to the weight of the brain, and the same may be said of those parts of the body which have to be moved. It is quite late before the principle of movement gets control over the upper parts ; and its control over those parts (such as the legs) whose movement is not closely connected with it is achieved last of all. Another such part is the eyeUd. Now, as Nature does nothing that is superfluous or pointless, it is plain that she will not do anything too late or too soon, for in that case what was done would be either pointless or superfluous. Therefore the separation of the eyelids and the ability to move them must coincide in time. Thus the completion of the formation of the eyes comes late, because of the large amount of concoction required by the brain, and it comes last, after all the other parts, because the movement * must be very strong and powerful in order to move parts which are so far away from the first principle,*' and so much subjected to cold. That such is the nature of the eyelids is shown by the fact that even if a very little heaviness affects the head through sleep or intoxication or anything of that sort, we are unable to raise the eyeUds although their weight is very sUght.

' Viz., of movement, i.e., the heart.


744 b

ARISTOTLE 10 Ilepi fiev ovv 6(f)daXixa)v ecprjTai ttojs yivovrai /cat 8i o Ti, /cat 8ta Ttv' alrlav reXevraiav Xajx^dvovaL TTjv SidpdpcoaLv.

Tajv 8' dXXcov yivcrai [xopLCov eKaarov e/c rrjs Tpo(f>rjs, rd ixev rtjutcorara /cat /xeretAi^^ora ttJ? /cfpLOJTarrjs ap)(rjs e/c t';^? TreTre^jU.eV'rjs' /cat KadapcordTTjs /cat TTpwTTjs Tpo(f)rjs, TCI 8' dj^ay/cata fjLopta /cat 15 TOfTcov ev€Kev e/c tt^s x^ipovos /cat rcSr UTroAet/ipLartov /cat TreptTTOJjLtdTcov. cjoTrep yap oIkovo^jLOS ayadas, /cat 7^ cf)vaLS ovdev drro^dXXeLV etcodev i^ (1)V €UTi TTOtrjcral ri XPV^'^^^- ^^ ^^ rats olkovofxlais rrjs yLvofxeu-qg rpo(f)rjs r) /xev ^eXrCarr) rera/crat rotS" iXevOepoig, rj 8e )(€Lpa}V /cat to 7re 20 pLTTCDfxa TavTTjs (roisy oi/ceTat?, to. 8e ;)(^etptcrTa /cat Tot? avvrpe(f>oiJievoLg 8t8oacTt Repots. Kaddirep ovv €Ls rrjv av^iqcnv 6 dvpaOev ravra 77otet i^ous, outco? ev TOt? yivopiivoLS avrotg tj (jyvais e/c juev tt^s /ca^apcordrrjs vXr]s adpKas /cat tcDv aAAcov aladrjrrjpioiv rd awfiara crvvLarrjaLv, e/c 86 rcov irepir 25 TcofiaTcov Sard /cat vevpa /cat rptxas, €ri, 8' ovu;(a? /cat OTrAd? /cat Trdvra rd roiavra' 8to TeAeuTata ravra XapL^dvet rrjv avaraaiv , drav ijSr] yiyvrjrat TT€pirra>pLa rrjs (f>va€Cos.

H {jLev ovv rojv oarwv (f>vais €v rfj Trpiorj) avardaei yiverai rcov piopiojv e/c rrjg a7T€pp,arLKrjs 30 Trepirrcbaetos , /cat ra>v t,a)a>v av^avopuevcov e/c rrjs . (f>vaLKrjs rpo(f>rjs Xapb^dvei rrjv av^rjatv, e^ rjarrep ra piopia rd Kvpia, ravrrjs pievroi avrijs rd vtto^ supplevit Richards.

" i.e., blood.

  • Cf. the regular distinction between " the better " and " necessity," " The sense-organ of touch.



This concludes our discussion about the eyes. We have said how they are formed, and why, and what is the reason that they are the last of all the parts to be articulated.

Each of the remaining parts is formed out of the nourishment. The most honourable ones, those which have a share in the supreme controlUng principle, are formed out of the first of the nourishment," which has been concocted and is purest ; the " neces>-ary " parts,* which exist for the sake of those just mentioned, are formed out of inferior nourishment, out of the lea^ings and the residues. Like a good housekeeper. Nature is not accustomed to throw anything away if something useful can be made out of it. In housekeeping the best of the food available is reserved for the freemen ; the residue left over from this as well as the inferior food goes to the servants, and the worst of all goes to the domestic animals. Here then is an instance of a mind, external to them, acting so as to pro\ide for their groA\'th. In the same way Nature is at work \Wthin the creatures themselves that are being formed, and constructs flesh '^ and the bodily parts of the other sense-organs out of the purest of the material, whereas out of the residues she constructs bones and sinews and hair, and also nails and hoofs and all such things, which means that they have to wait till Nature has some residue to hand, and that is why they are the last to be constructed.

The bones, then, are formed during the first stage Bones, etc. of construction out of the seminal residue, and as the animal grows they grow too. Their gro^^i:h is derived from the natural nourishment, which is the same as that which suppHes the supreme parts ; only they 2S1


744 b

AeijLt/xara /<at to. TrepLTTCOfiaTLKa. ylverat yap iv TTaVTl TO TTpOJTOV Kal TO SeVTCpOV TTJS"^ TpO(f)rjS TO lieV dpCTTTlKOV TO 8 aV^TJTlKOV, dpeTTTLKOV flCV 35 o TO €i,vaL 7Tap€)(€Tai TO) T€ oXii) Kal Tolg pLopioLS, av^TjTiKov 8e TO ets" p^eyeOos ttolovv ttjv eTxihoaiv vepl d)v voTcpov hiopiGTeov p^aXXov. tov avTov Se TpOTTOV ToXs OOToZs Kai TO. v€vpa avviOTaTaL Kal €K TOiv g.VTa)v, eK ttjs' a7Tepp,aTLKrjs TrepLTTCvaecos 745 a Kal ttjs 6p€7rTLKi]S- ovu;^e? 8e /cat Tpix^s Kal OTrAat /cat KepaTa /cat pvy^f] xai to. TrXrJKTpa tojv opvidcov, Kal et tl toiovtov €Tep6v ioTi popcov, e/c ttj? eTnKTTjTov Tpocfyrjs Kal Trjs av^r]TiK7Js, -qv re Trapa TOV drjXeos eTTLKTaTat, Kal [Trjg]^ 6vpa6ev. 8ta tovto 5 TO, /xev OGToi P'^XP '^Vos XapL^dveL ttjv av^iqaiv eoTL yap tl ttolgl tols ^cpot,g Trepas tov p^eyedovs, 8to /cat TTJs Twv ooTcov av^'qoecos . et yap TavT e?Yev av^rfaiv del, Kal tcov ^cowv oaa e;)^et ootovv ri TO dvdXoyov, rjv^dveT dv ecos €t,r}- tov yap p^eyedovg opog eotI raura toZ? Wot?. 8t' rjv p.ev 10 ovv aiTcav ovk del Xap^^dvovaiv av^rjGLV Xcktcov voTepov Tpix^s 8e /cat Ta avyyevrj tovtois, ecu? dv ^ Trjs Z : Kai rijg vulg. ^ Seclusi.

" The functions of "nutritive Soul" (see above, 735 a 17, and De anima 415 a 25) are to generate, and to make use of nourishment ; it is the same Svva/xis of the Soul which generates and which nourishes {De anima 416 a 19). In the passage which there follows, a distinction is made between being nourished {rp€<f>€a6ai) and growing {av^aveadai). At 416 b 11, Aristotle says that " nourishment " is not identical with " that which is growth-promoting " ; thus, in so far as the living thing (the creature " with Soul in it ") is of a certain quantity, the food is " growth-promoting " {i.e., increases its quantity) ; but in so far as the creature is a particular thing, an individual " being," the food is " nourishment," because 2S2


get merely the leavings and the residues of it. In every instance, of course, there is nourishment of two grades present : (1) " nutritive," that is to say, which proWdes both the whole and the parts ^nth being ; (2) " growth-promoting," that is to say, which causes increase of bulk. These ^%ill have to be more particularly distinguished later on." The sinews are constructed in the same way as the bones, and out of the same materials, viz., the seminal or " nutritive " residue. As for nails, hair, hoofs, horns, bills, cocks' spure and any other such part, these are formed out of the supplementary or " growth-promoting " nourishment, this additional nourishment being obtained from the female, and from outside. On this account, the bones continue growing only up to a certain point, for as all animals have a hmit to thensize, this involves a limit to the growth of the bones. If the bones continued growing for ever, then every animal which contains any bone or the counterpart of bone ^ would go on growing as long as it hved, because the bones set the limit for an animal's size. We shall have to explain later on whv the bones do not continue growing for ever. Hair and similar things, on the other hand, continue growing so long it maintains the creature^s being. And it is also " productive of generation " - not, of course, of the generation of the creature which is getting the nourishment, for its " being " is already there, but of another creature similar to it (416 b loll). It thus appears that the business of "nutrition" is concerned \*ith the maintenance of a living creature's being, and with the generation of new ones' being : " growth-promotion " is concerned with increasing the bulk of that which already has being - and this is precisely the distinction which Aristotle employs in the present passage.

  • e.g., the os sepiae, the '* pen " of calamaries, the cartilaginous spines of Selachia (sharks, etc.) {P. A. 6Si a ^0, 655 a 23).


745 a

ARISTOTLE v7Tap)(coatv, av^dvovrai, Kal ixdXXov iv voaois Kal TOiv acofxarcDv yrjpaaKovrcov koI <j)div6vTOiv hid to Aeineadai Trepirrcjjfxa irAetov eXdrrovos els to, Kvpia 8a7Tava)[X€vov Sid to yrjpas Kal ra? vocrovs, 15 CTret y OTav VTToXcLTTr} /cat tovto Sta ttjv rfXiKtav, /cai at Tpi)(^€g VTToXeLTTovatv . ra S' oCTxa TovvavTLoy avjxcfidiveL ydp to) aojpiaTi koX toZs fiepeaiv. av^dvovTai 8' at r/atp^e? koL TcdvedtTcov, ov puevToi yivovTai y' e^ VTTap)^}]?. ■Hepl 8' oSovTCOv dTToprjaeiev dv tls. elal ydp ttjv 20 fJicv (f>vaLv TTjv avTTjv e)(ovTes toIs doToZs, kol yivovTai eK Tcjv ogtiov, 6vv)(€S Se /cat Tptx^S Kai KepaTa Kal Td TOiavTa e/c tov SepfxaTos, Sto /cat aviJLfJieTa^dXXovai tco SepfiaTL to.? xP^^^' XevKa re yap Kal jxeXava yCvovTai Kal TravToSaird /cara ttjv tov Sep/jLaTos XP^^^> ^^ S' dSovTe? ovdev e/c ydp Tcbv oaTOJV eluLV, oaa tcjv ^cLodv ep^et oSovras" /cat 25 dara. au^avovrai 8e 8ta jStou jxovol tcov dXXcov OGTCov tovto 8e hrjXov eirl twv TrapaKXivovTOJV oSovTCDV TTjv d(f)r]v TrjV dXXrjXcov. aiTiov he ttjs av^rjoeois, cvs p-ev eveKa tov, 8ta to epyov rap^u ydp dv KaT€TpL^ovTO p,rj yivofJidvrjs tivos CTTippvaeois, enel Kal vvv ivLOis yqpdaKovat, tols ^pco 30 Tt/cot? /xev p,rj p^eyaXovs 8' exovai, /cararpt^ovTa t TTapiTTav TrXeLOVL ydp Xoyco KaOaipovvTai ttjs av^ijaews. 8td /cat tovto ev [Ji€p,rjxdvT]Tai rrpos to " In the case of rabbits, etc., it may happen that a tooth in the upper jaw and one in the lower grow outwards and thus continue growing indefinitely, so that finally the animal is unable to eat at all. 234


as they are there at all, and they grow more during diseases, and when old age advances, and when the body is wasting. This is because old age and diseases mean that less (nourishment) is expended on the supreme parts of the body and therefore more residue is left over ; though when even this begins to fail through age, the hair follows suit. With the bones, the reverse occurs : thev waste away along with the bodv and its parts. Hair actuallv continues to grow after life is extinct, though it vriW not begin growing where it does not already exist.

Teeth may present a puzzle. They possess the Teeth. same nature as the bones and are formed out of the bones ; nails, hair, horns and the Uke, however, are formed out of the skin, and that is why they change their colour along -with the skin : they turn white and black and all shades according to the colour of the skin. The teeth do none of this, because they are formed out of the bones (this applies of course only to such animals as have both teeth and bones). They are unique among bones in that they continue growing all through life, as is clear in the case of teeth which take an oblique direction and fail to conie into contact with each other." The reason for their growth, the purposeyor the sake of which they grow, is to discharge their special function : they would soon be worn down unless the loss were made good in some way,* since even as it is, in some aged animals which eat a great deal but have small teeth, they are quite worn away, because their growth is not proportionate to their loss. And so here too Nature has produced

  • L. & S. translate " unless there were some means of saving them " ; but Scot translates si non rrescerent consumerentur cito nisi esset materia ex qua crescunt.


ARISTOTLE avfi^alvov 7] <f)vcns' avvdyec yap els ro yrjpas /cat Trjv TeXevTTjv rrjv inroXetifjiv rwv oSovrcov. el 8' rjv jjivpterrj? 6 ^ios r] y^iXLeriqs , TrafjufxeyddeLs t av 35 eSei yivGodai, rovs e^ ^PXl^ '^'^^ <f>v€adai TroAAa/cc? ' KOL yap el crvvexfj ttjv av^rjaiv elxov, ofiojs av cixp'^oroL Xeaivopievot irpos ttjv epyaaiav rfaav. ov fiev ovv ev€Ka Xajx^dvovai rrjv av^tjULV, etpr^raf avix^aivei 8e firjSe rrjv avrrjv e^eLV (/)vcn.v rots dXXois oarots rovs oSovrag' rd [xev yap iv rfj 5 TTpwrrj avardaei yiVerat ndvra Kal ovdkv varepov, ol 8' oSoj^re? varepov. hto Kal ndXiv dvvavrat cf>vea6aL eKireaovres' aTrrovrai ydp, aAA' ov avpu7Te(f)VKaat, rot? oarots. e.K fievrot ttjs rpo(f)rjs rrjs els rd Sard SLaStSofievr^s ytvovrat, Sto rrjv avr-^v^ exovai (JivaLV, Kal rore orav cKelva exj) '^'817 tov 10 dpidfiov rov avrdjv. rd pbev ovv dXXa i^cpa exovra ylverai ohovras Kal ro dvdXoyov rols ohovaiv, edv pnq ri ylyvqrai irapd (fyvaiv, hid ro drroXveadai rrjs yeveaeojs rereXeajxeva rov dvdpwTTOV jxaXXov 6 8 dvdpa)7TOS, dv fjirj ri avfi^ij rrapd (j)vaLV, ovk excov. hi Tfv 8' alriav 01 piev yivovrai rcov ohovrcuv Kai 15 €K7TiTTrovaiv, 01 8' OVK eKTTiTTrovaiv, varepov XeXdrjoerai.

AiOTt 8' eK TTepirrwixaros eari ra roiavra rcov pLOplcov, hid rovr dvdpcoTTOS ipiXorarov re Kard ro acopia rcJov ^wcov Trdvrcov iarl Kal ovvx^-s eAa;^;/arovs ex^i (Ls Kard pieyedos' eXdxicrrov ydp ex^i ^ avrrjv Bekker, per typothetae errorem.

" Bk. V, ch. 8. ** i.e., hair, nails, etc.



an excellent device to suit the case, in making the failure of the teeth coincide ^^ith the time of old age and the close of life. If life went on for 10,000 or even 1000 years, the teeth would have had to be quite enormous to begin with, and they would have had to grow afresh many times over ; not even continuous growth would have sufficed to prevent them being ground do'svn and becoming useless for their work. We have now described the purpose for the sake of jvhich the teeth grow. And yet as a matter of fact the teeth do not possess the same nature as the rest of the bones, because the bones, without exception, are all formed during the first stage of the embryo's construction, whereas the teeth are formed later ; and that, too, is why a fresh set of teeth is able to grow after the old ones have fallen out : although they are in touch with the bones, they are not all of a piece ^vith them. Still, they are formed out of the nourishment which is distributed to the bones (which is why they possess the same nature), and at a time when the bones have already attained their full complement. All the animals except man already have their teeth (or the counterpart of teeth) when they are born - unless it be that something unnatural occurs - because when they are released from their process of formation they are more fully perfected than man ; man however when born has no teeth - unless something unnatural occurs. We shall explain later on '^ why some of the teeth are formed and fall out and why some do not fall out.

The reason why man's body is more naked than that of any single one of the other animals, and why he has the smallest nails in proportion to his size, is this. Parts of this sort * are made of residue ; now 237

ARISTOTLE 745 b , -^S " S^ ' ^ «  7re/)(.TTa)/xa yecooe?, eart oe TreptTTOjyLia /xev to 20 (xn^TTTOv, TO 8e yerjpov iv tols aco/xacrt TravTCDt" a7re77TOTaTOv.

riajS" ftev' ow CKaarov avviararai rcov {jLopicov, €LprjTai,, /cat tl Trjs yeviaecos amor.

VII E;;^ei Se tt^v av^rjaiv ra l^woTOKOv/xeva rojv ifi^pvcov, wairep eXej^d-q trporepov, 8ta rT]s rov 6pi(fi(i\ov TTpoacfivaecjos . cTret yap eveariv iv Tots" 25 ^ojot? /cat 9^ dpeTTTLKT] SvvapLig rrjs ipvxTJS, a^iriaLV evdvs olov pil,av rov 6pi(j)aX6v els ttjv varepav. eWi Se o 6fx<j>aX6s ev /ceAu^et ^Ae/Ses", Tot? /uev pLeit^oai TrXeLOVS, olov ^ot Kal rots tolovtois, toIs Se fxeaoLS Svo, pila he toZs ea-)(droLS. Sta Se ro'urov Xapi^dvec rrjv rpoijyrjv alp.aTiK'qv , at yap varepat 30 TTepara (f)Xe^cov ttoXXcov elaiv. ra puev ovv pLrj dpb(f)d)hovTa TTOLvra, /cat rcov dpL(j>a)h6vTa>v ocra>v rj varepa p,r] p,iav <j>Xe^a jJieydXrjv exei- hiareivovaav dXX dvrl pads irvKvas noXXds, ravra iv Tat? varepaig e)(ei rag KaXovp-evas KorvXrjSovas , Trpos a?^ o oficfjaXos avvdrrrei /cat TTpoairecjiVKev dvoreravrai yap at i^Xe^es at Sid tov 6[X(f)aXov evdev /cat evdev /cat a'^iiC^ovraL Trdvrr) Kara rrjv varepav fj Se TTepacvovai, ravrj) yiyvovrai at /coTi;A778di'es"/ TO jLtev rrepi^epeg exovaai^ Trpos rrjv varepav, ro 35 Se kolXov Trpos to efi^pvov. p,era^v Se rrjs varepas 746 a /cat tou ipi^pvov ro )(6pLov /cat ot vpueves etotv. at 1 5s Platt, Ob* : 5 P.

^ vpos as 6 6ix(j)aX6s • • • yiyvovrai ai kotvXt)S6v€s POb*S : cm. vulg. ^ e;(oiiffat Z et corr. P : €x°^^°-s vulg.

« See 740 a 24 ff.

•* Not quite the same as the modern use of the term. Aristotle uses it to mean the pits in the modified wall of the 238


it is unconcocted substance which constitutes residue, and the most unconcocted substance in animals' bodies is the earthy substance, and man has a smaller amount of earthy residue than the other animals.

We have now described how each of the parts takes shape, and what is the cause of their formation.

In viviparous animals, as stated earher," the embryo V'll obtains its growth through the umbilical attachment, t'^n "ft^g Since the nutritive faculty of the Soul, as well as the embryo, others, is present in animals, it immediately sends off the umbilicus, like a root, to the uterus. The lunbilicus consists of blood-vessels in a sheath. In the larger animals, such as the ox and the hke, it contains numerous blood-vessels, in medium-sized animals, two, and in the smallest, one. Through this the embryo gets its nourishment, i.e., blood ; the uterus being the terminus of many blood-vessels. The cotyledons * (as they are called) are present in the uterus (o) of all those animals which have no front teeth in the upper jaw, and (6) of those which have teeth in both jaws and also have a cluster of bloodvessels running right through the uterus instead of a single large one. The umbilicus is connected up to these cotyledons and firmly attached to them ; for the blood-vessels which pass through the umbilicus extend in both directions and branch out all over the uterus, and it is at their terminal p)oints that the cotyledons are formed. Their convex side is towards the uterus, their hollow side towards the embryo. Between the uterus and the embryo are the chorion and the membranes. As the embryo grows and uterus into which the villi of the outer membrane of the embryo fit. For the meaning attached to the term by Diocles, see Welbiiann, reference in note on 746 a 19 below.


746 a

ARISTOTLE 8e KOTvXr]S6v€s av^avo[ji€vov Kal reXeovfjievov rod ijji^pvov yivovrai iXdrrovs, /cat tcAo? d(f)avi^ovTac reXecoOevros. els tovto yap TTpoeKrWeTai rols i/ji^pvoLS Tj (f>vaLS TTjV alpLaTLKrjv rpocjy'qv rrjs varipas cjOTTep els fxaarovs, /cat Sta to a.dpoLt,e5 aQai Kara} puKpov e/c TroAAoiv olov e^dvdrjp^a /cat (fyXeypLaaia yiverat to acopca to ttjs KorvXrjhovos . ecus p-ev dv ovv eXarrov fj ro ep^^pvov, ov Svvdpevov TToXArjv Xap,^dv€LV rpocjyrjv, SrjXat clai /cat /xet'^ores", av^fjdevros Se avpLTTLTTTOVOLV.

To. 8e TToAAa Twv koXo^cov t,a>iov /cat dp,(f)a)B6vTCov 10 ovK e^ei. KorvXrjhovas^ iv raXs varrepats, aAA' o 6pL(f)aX6s els (j>Xe^a TetVet pbiav, avrr] Se rerarat 8ta TTJs varepas exovaa p,eyedos. CTrel 8e rd p.ev pLovoroKa rd he TToXvroKa ribv toiovtojv earl t,(x)wv, Kal rd TrXeioi tcov epi^pvcov tov avrov e)(eL rpoirov TO) evi. 8et 8e ravra decopetv e/c re rcov 15 TTapaheLyp.dra)v tcov iv rats dvarop,als /cat tcov ev Tat? laroplais yeypap.pLevcov. ire^vKacTL ydp rd t,ipa e/c rod op(f)aXov, 6 8' 6p,cf)aX6s e/c rrjs (f)Xe^6s, ecfje^-qs aAArjAot?, waTrepavel Trap* oxerdv rrjv (fiXe^a peovaav irepl Se eKaarov rcov ep-^pvaiv ot 6 V peeves /cat rd ^ppiov eanv.

Ot Se Aeyoi^Te? rpe(f)eadaL rd TratSta ev rats 20 varepats Sta rov aapKihiov Tt ^SaXXetv ovk opdios ^ Kara P : Kal Kara vulg. ^ KOTvX7]S6vas P : KOTvXrj86va vulg.

" Here seems to mean " hornless." Aetius ascribes a similar theory to Democritus and Epicurus (Aet. 5. 16 ; see Diels, Vorsokr.^ 68 A 144) ; Censorinus {De die natali 6. 3; Diels 38 A 17) to Diogenes and Hippocrates. Cf. Hippocrates, it. oapKcov 6 (viii. 592 240


approaches its completion the cotyledons become smaller, and finally when it is completed they disappear. Nature lays in a store of the blood-like nourishment for the embryos in this part of the uterus, as it were into breasts, and the body of the cotyledon becomes as it were an eruption or an inflammation owing to the fact that the numerous cotyledons gradually get compacted together. While the embryo is fairly small, and unable to take much nourishment, they are large and plainly visible, but when it has grown they shrink up.

The great majority of the " stunted " " animals, and of those that have front teeth in both jaws, have no cotyledons in their uterus, but the umbilicus extends to meet a single blood-vessel, which is a large one and extends throughout the uterus. Some of these animals produce one at a birth, others several ; but what occurs when there is only one embryo occurs also when- there are more. All this should be studied ^\â– ith the help of the illustrative diagrams given in the Dissections and Researches. The embryos are attached each to its umbihcus, and the umbilicus is attached to the blood-vessel : they are arranged one after the other along the stream of the bloodvessel as it might be along a runnel in the garden ; and there are membranes and a chorion around each embryo.

Those people ^ who say that children are nourished in the uterus by means of sucking a bit of flesh are Littre). Tha view that the embryo sucked the " cotyledons " was held by Diocles of Carystus (Wellmann, Fraginentsammlung der sikellschen Arzte, Diocles fr. 37, 10 ff.) ; and according to Jaeger (Diokles von Karystos, 166), Aristotle's detailed treatment of the subject o'f cotyledons here is due to the fact that Diocles was associated with him in the Lyceum.


ARISTOTLE 746 a , , , ^ Aeyovaiv €7tl re yap rcov aAAojv C,cpojv ravrov avve^aivev dv, vvv 8' ov ^atVerai {decopijaai yap TOVTo paSiov Sta rcov dvaTOfXcJjv)- /cat nepl dnavTa TO. ejjL^pva Kal rd inrjvd /cat rd irXcord kol rd rcov TTe^cov ofiOLOis XeTrrol TrepLe)(ovaLv u^eVe? X^~ 25 pLL,ovres diro re^ ri]? varepas /cat rcov eyyivopievcov vypojv, ev ot? ovr^ avrolg eveari roiovrov ovdev, ovre Sta rovrojv ovdevos ivhex^rai TTOLeladai rr^v aTToXavatv rd 8' (poroKovfieva Trdvra on Xapu^dvei rrjv av^rjcnv xcopiadevra rrjs pnqrpa? ^i^j, (jiavepov.

Tiverai Se o avvhvaapios rols ^coois Kard cJjvglv 30 fJi€v roLS o/jLoyeveoLV, ov pirjv dXXd /cat rots' jLtev avveyyvs^ rrjv (f)vaLv exovaiv, ovk dStat^opot? 8e rw eiSet, idv rd re fieyedrj TvapaTrXiqata fj /cat ot Xpovoi tact cucrt rijs Kvrjaeojs. cnrdvia juev odv yiverai rd roiavra eirl rdJv dXXcDv, yiverai 8e /cat errl Kvvibv /cat dXoiTTeKCJV /cat Xvkchv {/cat dcocovy' 35 /cat ot 'IrSt/cot 8e Kvves e/c drjpiov rtvos" /cuvajSou? 746 b yet'i'ait'Tat /cat /ci/vd?. /cat eTTt tcDv opvidcov he. rdJv ox^vrLKcov (Lrrrai rovro avfJi^alvov, otov errl rrepSiKcov /cat dAe/CTO/3t8ajv /cat rdJv yapupcDvux^^v ol lepaKes SoKOvaiv at hLa(j>epovres rat etSet pbiyvvadai 77/30? dXXriXovs' /cat eV dAAoji/ Se Ttvojv 5 opvecov e^ei rov avrov rpoirov. errl 8e roiv daXarricov ovdev d^ioXoyov ecoparat, hoKovai Se judAtara " ^ T6 P : om. vulg. ^ aweyyv? SZ* : iyyvs vulg.

=• Btf. ; vid. p. 563.

o C/. H.A. 607 a 4 ff. " they say too that the ' Indian dog ' is the offspring of a tiger and a bitch ; not the first cross, but the offspring at the third generation." There seems to 242


mistaken. If this were true, the same would occur in the other animals, but it is not found to do so, as can be easily observed by means of dissections. Also, all embryos alike, whether they be of animals that fly or swim or walk, have round them fine membranes which separate them from the uterus and from the fluids which are formed there ; and there is nothing of the sort in these membranes nor can the embryos get the benefit of anything whatever through them. As for embryos that are produced by means of eggs, it is of course obvious that in all cases their growth takes place outside the uterus, after they have been separated from it.

The partners in copulation are naturally and ordi- Hybrids, narily animals of the same kind ; but beside that, ®*'^' animals that are closely allied in their nature, and are ryot very different in species, copulate, if they are comparable in size and if their periods of gestation are equal in length. Although such crossing is infrequent among the majority of animals, it occurs among dogs, foxes, wolves (and jackal';) : the Indian dog " also is produced from the union of a dog ^^^th some \\i\6. doghke beast. It has also been observed to occur among those birds that are salacious, e.g., partridges and common fowls. A case among the crook-taloned birds is that of the hawks, different species of which copulate, as it appears ; and the same occurs among certain other birds. We have no trustworthy observation of its occurrence among sea-animals ; but there is a strong suspicion that the rhinobates as it is called is produced by the copu be no general agreement as to what this animal was ; see Platt's note, C.Q. Ill (1909), 241 S. Cf. too the " Laconian hound," 738 b 31.


746 b

ARISTOTLE OL pivo^draL KoXovjxevoi yiveadai e/c pivrfs /cat Pdrov avvhvat,oyLeva>v. Xeyerai Se /cat to irepl rviS Al^vtj^ 7TapoLfjiLat,6fi€vov, <bs del rt rrjs Al^vtjs Tpecfiovarjg Kaivov, 8td to fxiyvvadat Kal 10 ra fiTj 6fjL6(f)vXa dXX-qXoLS Xe'xdrjvai tovto- Sta yap TTjv OTTavtv tov vSaTOS aTTavTcovTa TtdvTa Trpos oAtyous' TOTTovs Tovs e)(ovTas vdpLaTa fjiiyvvadai /cat ra jjltj ojjioyevrj.

Ta fjitv ovv dXXa tcov e/c rotauTTj? jjiL^ecos yivofMevcov avyhva^ofjieva ^atVerat TrdXtv dXX-^Xoi? Kal IXLyvvjxeva Kal Svvdfieva to t€ drjXv Kal to dppev 15 yewdv, ol 8' opels dyovoi p.6voi tcov tolovtcov ovt€ yap 6^ dXXiqXojv ovt^ a'AAoi? pnyvvixevoi yevvwaiv. koTi 8e TO TTp6^Xr)jj,a KaOoXov /xeV, 8ta rtV atrtav dyovov Tj dppev rj drjXv ioTLV elal yap Kal yvvaiKes KO.L dvhpes dyovoL, Kal tcov dXXcov ^cocov iv tols yevecrtv e/caaTot?, olov ev lttttols /cat Trpo^aTOis.

20 dAAo, TOVTO TO yevos oXov dyovov ecrrt, to tcov TjpLovwv. Ta 8' aiTJa ttjs dyovcag ijrl fjiev tcov dXXcov TrXeico avp^^aivef /cat yap €K yeveTijs, oTav 7n]pa>da)aL tovs tottovs tovs Trpos ttjv p-i^LV -^prjoip-ovs, dyovoL yivovTai /cat yvvaiKes /cat dvhpes, ojoTC Tas p-kv py] rj^dv tovs Be p,rj yeveidv, dXX 25 evvov)(tas BiaTeXeXv ovTas' toZs Be Trpo'Covcrqs ttjs TjXiKLOs TavTov CTf/LtjSatVet Trdax^i'V, ore piev 8t' evTpo(f)iav tcov acopLdTCOv (rats' p^ev yap TnoTepais « The batos is a flat-fish {P. A. 695 b 27, 696 a 26), called by Thompson (translation of H.A. 566 a 27) the " skate," by Platt, a " ray." The rhine is called by Thompson the " angelfish " (note on H.A. 540 b 11), by Platt, a '-'shark." At H.A. 566 a 27 if. Aristotle again refers to the rhinobates as a cross between these two fishes, and says that it has the head and foreparts of the batos and the hindparts of the rhine.



lation of the rhine and the haios." Also, the origin of the proverb about Libya, to the effect that " Libya is always bringing forth something new," * In said to be that there animals of different species unite, since owing to the fact that as there is very little water they all meet together at the few places where springs are to be found, and so animals of different species unite.

It is kno\\Ti that with one exception all the animals which are produced as a result of such unions copulate with each other and unite in their turn and are able to produce young of both sexes. Mules are the one exception. They are sterile and do nqt generate either by union with each other or with other animals. It is, of course, a general problem why any particular male or female is sterile : there are men and women who are sterile, and there are instances in the several kinds of animals, e.g., horses and sheep. But with the mules we have a whole race which is sterile. Lea\ing this exception for the moment : elsewhere the causes of steriUty are numerous, (a) Men and women alike are sterile from birth if they are deformed in the regions employed for copulation ; as a result, the men do not grow a beard but remain as eunuchs, while the women do not reach pubertv' ; (6) others become sterile as they advance in age, sometimes (i) because they have put on too much flesh : in men Platt thinks the rhinobates is the angel-fish ; Thompson offers the opinion that it is " probably the modern genus Khinohatus " ; Platt says " it certainly did not belong to the modern genns of that name."

  • For this proverb and its explanation, <•/. the similar passage H.A. 606 b 19 if. Platt suggests that a mutilated passage in Hippocrates, tt. aepojv vSarcov tottcov 12 Jin., contained a statement on this subject.



746 b

yLvofxevaig rols 8' eveKTiKwrepoLs etV to acJoixa KaravaXtaKeTaL to TTepvTroi^a to anepfjiaTLKov, Kai TOLS fJiev ov yiveTai /cara/Ltr^via rot? 8e 701^17), 6t€ 30 Se §ta voaov ol [xev vypov Kal iltv^pov Trpotevrai, rat? Se yvvai^lv ai Kadapaeig (f}avXat Kal TrXiqpeLS voarjixaTLKcbv TTepLTTOJjJiaTOJV. ttoXXols Se Kal ttoXXais Kal 8ta TrripiopuaTa tovto avpL^alvei to Trddog TTCpl TO, /LtOpta Kal Toils' TOTTOVS TOVS 776/01 TI7I' ofiiXiav -x^priaiixov's. yiveTai he to. fiev taro. to. 8' dviara tcDj^ tolovtcov, /xaAicrTa' Se 8iaTeAoi'CT(.j^ 35 dyova {ray /cara tt)]^ TrpcoTrjv avoTaaiv TotavTa 747 a yevofxeva' yivovTai yap yvvacKe^ re appevojirol Kal avhpes drjXvKOL, Kat Tals [xev ov yiveTai tol arara fX'qvLa, TOtS" 8e to onepfxa Xctttov Kal ipv)(p6v.

hioTTep evXoyojs ^aaavt^eTai Tals Treipais to ye TUiV dv8pa)v, el dyovov, ev toj iJ8aTf Ta)(v yap 5 Sta^eiTaL to XerrTov Kal tfjv)(p6v eTTtTToXrjs , to 8e ' yovifxov els ^vOov y^copel' deppbov p,ev yap to ne TTepLfievov eoTL, TreTreTTTat 8e to uvveuTr]K6s Kal TTOL^os ^X^^- '^^^ ^^ yvvatKas ^aGavLt,ovai tols t€ TTpoaOeTois, edv BuKvwvTai at oa/xai Trpos to TTvevpia TO dvpa^e KaTCoOev dvoi, Kal tols eyxpi 10 CTTotS' els Tovs 6(f>daXpLovs ;\;p6L»/LiaCTiv, dv ;i^pa;jLtaTt^cuat TO ev TCp OTop-aTi VTveXov. TavTa yap ov avjjL^alvovTa StjXol to adjp^a tovs vopovs 8t' cLv (XTTOKpiveTai TO TrepLTTCxjpba avyKe)(vp.evovs e^etv Kal avpLTTe^VKOTas . o Te yap Trepi tovs 6(f)6aXp.ovs TOTTOS tG)V Ttepl Tr]v K€(f}aXr]v aneppiaTLKcoTaTOS ^ TO. supplevi : post avaramv P.

" And therefore might be expected to rise. 246



who are too well fed and in women who are too fat the seminal residue is used up for the benefit of the bodily system, so that no semen is formed in the men and no menstrual discharge in the women ; sometimes (ii) because of disease ; the semen which the men emit is fluid and cold, and the discharges of the women are poor and full of morbid residues. But in very many cases, in both sexes, this drawback is due to deformities in the parts and regions employed for intercourse. Some of these deformities are curable, some are not ; those, howev^er, who have become deformed during the original constitution of the embryo, have a special tendency to remain infertile throughout ; thus, mascuUne-looking women are produced in whom- the menstrual discharges do not occur, and effeminate men whose semen is thin and cold. On this account the water-test is quite a fair one for infertiUty in the male semen, because the thin, cold semen quicklv diffuses itself on the surface, whereas the fertile semen sinks to the bottom ; for though it is true that a substance which has been concocted is hot," yet that which has been set and compacted and possesses thickness ** has certainly undergone concoction. Women are tested (a) by means of pessaries : the test is whether the scent of the pessary penetrates upwards from below to the 1 .reath which is exhaled from the mouth ; (6) by means of colours rubbed on to the eyes, the test being v.hether they colom- the sahva. If the required result is not forthcoming, it is proved that the passages of the body through which the residue is secreted have got obstructed and have closed up, for of all the regions in the head the eyes are the most seminal,

  • As is shown by its sinking. Cf. 765 b 2.


ARISTOTLE 747 a 15 iariv. dr)Xol 8' eV^ rals ojLitAiats" /Lterao-^^T^/xaTC^o fxevos iTTiSjjXcos fiovo?, /cat toIs ;)(/ooj;ueVot? TrXeio atv a^pohiaioig evhihoaui to. OjU/xara ^o.vepojs.

aiTLov S oTt T^ TTJ? yoj^? ^vci? ofjLOLCog e;)(ei tt^ Tou eyKecfxiXov vSanoSr]^ yap ianv rj vXt] avTTJs, -q 8e depfiorrjs €7tlkt7]tos. Kal at aTrepfiariKal 20 Kaddpaets diTO rov UTro^co/xaTO? eloiv, r) yap dpx'rj ttJ? (f)vaews ivrev6ev, cuare SuKveladac rrpos rov dcopaKa TttS" Kivijaeig oltto tojv dpdpwv at 8' e/c Tou da)paKos oajxal iroiovaiv alaOrjOiv 8td ttj? dvaTTVo-fys".

Ev /xev ow roLS dvdpojTTOLS Kal rot? dAAot? yeveatv, waTrep e'CprjTai, irporepov, Kara fiepog rj VIII 25 roiavrrj cry/xjSatVet TTijpcoais, ro 8e rwi' rjixtovcov yevo'S oXov dyovov eariv. nepl 8e t-^? atrta?, cos" //.ef AeyouCTiv 'Eju,7re8o/cA7]S" /cat ArifioKpiros, Xeycov 6 fX€V ov aa<f)(i)S, ArjfxoKpLros 8e yvcopipicos puoXXov, ov KaXcos elpiqKaaiv. Xeyovai yap eVt Trdvrcov d/xota)? rrjv aTToSec^LV rojv rrapd rrju avyyei'€iav 30 crvvSvat,oiJL€va}v . ArjpLOKpiTos /xev ydp (f)r)at Ste(f)ddpdai. rov? rropovs^ rcov rjfiLovcov iv rals voripais 8td ro p,rj €k avyyevcov yiveadai rrjv dpxrjv rajv t^cpcov. avpL^acvet, 8' e0' irepojv t,(x)Ciiv rovro jxev VTrdpx^i'V, y€vvdv 8e jxrjSev rJTTOV KairoL XPW> e'iTrep atriov rovr' rjv, dyova Kal toAA' ett-at ret jjiiyvvfieva rov rpoirov rovrov. 'EjUTreSo/cA-f^S' 8 35 alridrai ro /xty/xa ro rcov (TTTepp-drcov yiveadai 747 b TTVKVov €K jJiaXaKrjg rijs yovfjs ova'qs eKarepas' avvappLorreiv ydp rd KoZXa rots ttvkvoZs dAAT^Aoir, ^ eV P : eV jMiv viilg. * oTropovs YZ.

" Cf. Plato, Timcteus 91 a, b.



as is proved by the fact that this is the only region which unmistakably changes its appearance during sexual intercourse, and those who overfrequently indulge in it have noticeably sunken eyes. The reason is that the nature of the semen is similar to that of the brain " ; its matter is watery whereas its heat is a mere supplementary acquisition.* Also the seminal discharges come from the diaphragm, because the first principle of the natural organism is there, '^ so that the movements initiated in the genital organs penetrate to the chest, and the scents from the chest become perceptible through the breathing.

As I said earlier, this particular deformity occurs Mules, in man and in the other kinds of animals to some extent, but \\ith mules it is the whole race that is VIII infertile. What Empedocles has to say about the reason for this is obscure ; Democritus is more intelligible ; but they are both wrong. They give one omnibus explanation, covering all cases of copulation between animals of different kinds. Democritus '^ says that in mules the genital passages are destroyed in the uterus, because the formation of these animals has its origin in parents of different species. But we find this same situation with other animals, and yet they generate notwithstanding ; whereas, if Democritus's explanation was right, all other animals which unite in this way ought to be infertile too. The cause alleged by Empedocles is this : He says « the mixture of the seeds becomes dense as a result of the tno component portions of semen being both soft ; because, the hollows of one ft into the densities of the other, and in » See Introd. § 69. ' See 719 a U.

See Diels, Vorsokr.'^ 68 A 151.

â– = Diels, Vorsokr.^ 31 B 9:2 ; c/. 91 ; and 31 A 82.


747 b

ARISTOTLE e/c Se rcbv roiovrcov yiveadai e/c jxaXaKcov aKXrjpov, (Larrep rco Karrnepco /xip^^evra rov â– )(aXK6vy Xeycov ovr* inl rov ^(aXKov /cat rod KarTtrepov ttjv airiav 5 opdaJs {etprjrai S' ev tols tt po^Xripiaai Trepl aurcSv) ovB* oX(x)s €K yvcopifJLCov TTOLovixevos rag ap^o-S. ra yap KolXa /cat to, arepea dpfJiOTTOvra aAAi7Aots' ttojs TTOiet rrjv fxl^iv olov o'lvov /cat vSaros; rovro yap VTrep rjfjids iarl to Xeyopbevov ttojs yap Set Xa^elv 10 TO. KotAa Tov OLVOV /cat Tov vSaros, Ai'av eart rrapa rrjv aiaoiqaLV. en o eTreiorj cru/xpatvet /cat eg tTTTTcov- yiveadai lttttov Kal i^ ovcov ovov /cat e^ LTTTTOV /cat ovov rjpiiovov, apb(f)OT€pu}s dppevos /cat ^i^Aeog oTTorepovovv ovros, Sid ri e/c ^ev rovrcov yiverai ttvkvov ovtojs ojot' dyovov etvat ro yevo[xevov, e/c 8' lttttov O'qXeog /cat dppevos rj ovov 15 driXeos Kal dppevog ov yiverai dyovov ; /catVot fxaXaKov Kal to tov dppevos lttttov earl /cat to Tov 6-qXeos, piLyvvTaL 8e /cat o drjXvs lttttos Kal 6 dpprjv TO) ovcp, Kal tco dppevL Kal to) drjXei. /cat 8ta TOVTO yivovTaL dyova e^ dpi(/)OTepivv, d)s (f>r]<yLV, OTL e^ d{X(f)OLV ev tl ytVerat {ttu/cvov)/ /xaAa/ccDr 20 ovTOJV Tcov aTTeppbaTCOV . eSet ow /cat to e^ tTTTToy dppevos Kal BrjXeos yLvopbevov. el /xev yap ddrepov epiyvvTO [jlovov, evrjv dv Xeyeiv otl darepov atVtov TOV p.rj yevvdv dvopoLov ov^ Tjj tov ovov yovfj- vvv 8 otarrep ovarj eKeLvrj pilyvvTaL, TOLavTrj Kal tjj tov ^ TTVKVOV supplevi {ttvkvov Tl pro ev rt Platt) : on . . . anep/iciTcov om. S.

^ dvofjLoiov ov Platt {non assimilatur S) : ofxotov vulg. : ofioiov ov P {yevvav rj/xiovov coniecerunt A.-W.).



such circumstances tiro softs give rise to one hard, just as bronze mixed with tin does. In the first place, he has got the reason wTong in the case of bronze and tin (see what I have ^%â– ritten about this in the Problems),'^ and further, to put the objection generally, the principles from which he starts his argument are not intelhgible. How do the hollows and soUds by " fitting on to one another " produce " the mixture as of wine and water " ? This saying of his is over our heads ; it is quite beyond our perception what we are to understand by the " hollows " of wine and water. Further, in point of fact, a horse is the offspring of two horses, an ass of two asses, a mule of a horse and an ass - i.e., its sire is a horse and its dam an ass or vice versa, ^^^ly is it then that a horse and an ass produce something so " dense " that the offspring formed is infertile, whereas the offspring resulting from a male and female horse or from a male and female ass is not infertile ? After all, the secretion of both the male and of the female horse is " soft," and both sexes of the horse unite ^\"ith asses of the opposite sex. The reason why in both these cases the offspring produced is infertile, according to Empedocles, is because the one product of the two soft " seeds " is something (" dense ">. But then so it ought to be when the two seeds originate from two horses. If only one sex of the horse united with the ass, it would be open to Empedocles to say that the cause of the mule's infertihty was the dissimilarity ^of that one sex to the semen of the ass. In fact, however, there is no difference in quality between the seed of the ass Mith which it unites (to form a mule) " No such reference can be found. » Cf. Anal. Post. 100 b 9.


ARISTOTLE (Tvyyevovs. eVt 8' 77 [lev oLTToSei^is /car' d^(f)OT€po}v eiprjTai ofiolcos /cat* rov drjXeos /cat rov dppevos, 25 yep'va 8' o apprjv eTrrairy]? cov ■qpLiovos, o)S (f>aaLV' aAA 1^ drjXeta ayovos oXcos,^ /cat auTT^ roi /xt^ e/cTpe(f)e.iv el? reXog, eVet •^'Sr^ Kvrjfxa ecrx^v rjjXLOVog.

"lacos 8e /xaAAov av Sol'eiev OLTToSeL^is etvai TTidavrj rcbv elprjfievcDv XoyiK'q. Xeyco 8e XoyiKrjv 8ta TovTO, on oato KadoXov fxaXXov, TToppcoTepoj 30 Ta)v OLKeicov iarlv ap-)(cov. can Se TOLavrr) tls. el yap i^ o/Lto€t8a)v appevos /cat d'qXeos o/xoet8es' yiveaOai 7Te(f>VK€ tols yevriqaaaiv appev ^ OrjXv, otov e/c Kvvos appevog /cat d-qXeos kvcov dpprjv iq drjiXeia, /cat e^ erepcov rw et'Set erepov ro) etSet, otov el Kvojv erepov Xeovros, /cat e/c kvvos appevos 35 /cat AeovTO? d-qXeos erepov /cat e/c Xeovros dppevos Kttt /cm'o? dy]Xeos erepov coar iTTeiSr) ylverai •qpLLOvos dpprjv /cat drjXvs aStac^opoi oVre?* to) et'Set aAArjAots", ylverai 8' e^ lttttov Kal ovov rjpilovos, erepa 8' ecrrt rw et8et ravra /cat ot rj/jLLOvoi, dSvvarov yeveadai e^ 'qptovcov erepov yap yevos 5 ovy^ olov re 8ta ro e^ dppevos /cat diqXeos rdJv ofioeiScov ravro ylveodai ra> et8ei, rjp.iovos 8' on ^ Kal am. P, A.-W. : o/xot'wj hie om. A.-W., qui post dppevos inserunt, secuti cod. P, qui ibi ojxoiws iterum, sed opQcJs SYZ.

^ -quiovos Pc(;k : pLovos vulg. : Platt omisso (cum S) /xovos scribit mox 6-^Xeta <.pi6vrf>.


  • correxi : dSta^o/jcov ovtojv vulg.

" They are both " soft," according to Empedocles. 252


and the seed of an animal of its own species." Further, Empedocles applies his argument equally to the male and the female. . But, people say, the male mule does generate at the age of seven years ; it is the female which is totally infertile and that is simply because she fails to bring the nourishing of the fetation to its completion (as instances of fetations in mules have been known to occur).

Still, perhaps an abstract argument might be considered more con\incing than those which we have already mentioned. I call it an abstract one, because in so far as it is a more general argument it is further removed from those principles which belong to this particular subject. It goes somewhat hke this. In the normal course of nature the offspring which a male and a female of the same species produce is a male or female of that same species - for instance, the offspring of a male dog and a female dog is a male dog or a female dog. Two animals which differ in species produce offspring which differs in species ; for instance, a dog differs in species from a hon, and the offspring of a male dog and a female hon is different in species ; so is the offspring of a male lion and a female dog. This being so, it follows that as both male and female mules are produced, which of course do not differ in species, and as a mule is the offspring produced by a horse and an ass, both of which are different in species from the mule, it is impossible for any offspring to be produced by mules ; the reason being : (a) no offspring of a different species can be produced by them, because the offspring of two animals male and female of the same species belongs itself to that species, nor (6) can a mule be produced, because that is the offspring of a horse and an 253

748 a

ARISTOTLE eg LTTTTOV Kol ovov yiv^Tai irepcDV ovtcdv tw etSet [e/c 8e Ta)v irepcov rco etSet erepov ireO-q yiveadaL t,ipov^} ovTOS pikv ovv 6 \6yos KadoXov Xiav koL Kevos. oi yap jjurj €k rciJv olKcioiv dpxo^v Xoyoi Kevot, aAAa Sokovglv elvat rcov Trpayfidrcov ovk 10 ovres. OL yap e/c rwv dpxcov twv yewixerpiKtov yecofjieTpLKOL, ofioiwg Se Kal etrl rcov dXXcov to Se K€v6v 8oK€L fji€v clvai TL, eoTL 8' ovdev . OVK dXrjdeg Se, on TToXXd rcov fXT) (_e^y ofJLoeiSdJv yevo/xevcov ytverai yovipia, Kaddrrep eXe-)(drj rrporepov. rovrov fxev ovv rov rpoTTOv ovre irepl rchv dXXcov Set l^rjreLV 15 ovre rrepc rdjv ^vaiKcJbv e/c Se rcx)v vnap^ovrcov rco yevei rco rwv lttttcov Kal rco rcov ovcov decopcov dv ris fidXXov Xd^oL rrjv alrlav, on Trpcorov jxev eKarepov avrwv ean piovoroKov eK rcov avyyevcov ^cpcov, eVeir' ov avXXrjTmKa rd dr]Xea eK rwv appevcov del, hiorrep rovs Xttttovs hiaXeifrovres 20 o)(evovai [Sto. ro pbrj BvvaaOaL avvex<^S cfjepeiv].^ aAA' Tj fiev 177770? ov KarapirjVLcoSrjs , dAA' eXd^iarov TTpoterai rcov rerpaTTohcov rj S' ovog ov Several r-qv ox^eiav, aAA' e^ovpeZ rov yovov, Sio piaanyovatv dKoXovdovvreg . en Se ipv^pov ro ^cpov [6 oVos"]* eoTt, SiOTTep ev rols ;^ei/Lte/)ivors" ov BeXei ytveadai 25 roTTOis Sto. ro hvapiyov elvac rrjv (f>vaLV, olov irepi ^Kvdas Kal rrjv opcopov ^copav, ovSe rrepl KeArous' rovs VTTep rrjs 'I^r^pta?- ijjvxpd yap Kal avrr] rj 1 e*c Se . . . luiov vulg. : eicit Platt.

  • e^ supplevi. * seclusit Platt : habet vulg., 2.

  • seclusit Rtf.

« Cf. H.J. 577 a 23. 254


ass, two animals which differ in species [and it was laid dawn that an animal of a different species is produced by two animals that differ in species]. Now this argument is too general ; there is nothing in it J because there is nothing in any argument which does not start from the first principles belonging to the particular subject. Such arguments may appear to be relevant, but in fact they are not. For a geometrical argument, you must start from geometrical principles, and the same applies elsewhere ; that which is empty, which has nothing in it, may appear to be somewhat but in fact is nothing at all. But also, this argument is false, because many of the animals that are produced from parents of differing species are fertile, as I have said earher. No ; this method of inquiry is as wrong in natural science as it is elsewhere. We shall be more Hkely to discover the reason we are looking for if we consider the actual facts with regard to the two species, horse and ass. First, then, both horse and ass, when mated with their own kind, produce only one at a birth ; secondly, the females do not on every occasion conceive when covered by the male, and that is why breeders after an interval put the horse to the mare again [because the mare cannot bear it continuously]. Mares do not produce a large amount of menstrual discharge ; indeed they discharge less than any other quadruped ; she-asses too do not admit the impregnation, but pass the semen out with their urine ; and that is why people follow behind, flogging them." Further, the animal is a cold subject ; and as it is by nature so sensitive to cold, it is not readily produced in wintry regions, such as Scythia and the neighbouring parts, or the Keltic country beyond Iberia, which is also a 255


748 a

Xtjopa. Sea Tavr7]v Se rrjv alriav koI ra 6)(€La evL^aXXovcn roXs ovols ovx ojCTTrep rolg trrTrois /car' LGiq^epiav, dAAa rrepl rporra? depivd^, ottojs iv 30 aXeetvfj yLvrjrai cjpa ra TTCoXia {iv rfj avrfj yap yiverai iv rj av ox^vdfj- ivtavrov yap kv€l /cat LTTTTOS /cat ovos). ovTos S' waTTcp eiprirai ifjvxpov TTjv (j>v<jLV, Kal TTjv yovrjv dvayKaiov etvai rod roiovTov ijjvxpdv. {arjpLelov Se rovrov Sta tovto yap, eav jxev Ittttos dva^fj iirl cj-x^ev p.ivr]v vtto ovov, ov hia^deipei rrjv rod ovov 6)(^eiav, 6 8' ovos 35 eav eTrava^ij, SuacfiOetpei, rrjv rod Ittttov Std 748 b tpvxpdrrjTa rrjv rod aTrippiaros.) orav fiev ovv dXX-qXois pLLX^ajcTL, aco^erai Std rrjv daripov deppLorrjra, deppuorepov yap ro dno rod Ittttov dTTOKpLvofievov Tj fjiev yap rod ovov ipvxpd /cat rj vXr] /cat rj yovrj, rj Se rod Ittttov deppLoripa. orav Se 5 l-it-X^fj y) depfiov eVt i/jvxpov 'q tpvxpov eVt deppiov, avpL^atv€L avro fiiv ro iK rovrojv Kvrjpua yevopuevov^ acu^eadaL /cat raur' e^ dXXijXojv etvai y6vip,a, ro S' e/c rovrcov pirjKerL yovipLOv dXX dyovov els reXeioyoviav.

OXojs o VTTapxovrog eKarepov €V(/)Vods TTpos ayoviav, rep re yap ovco VTrdpxei ra dXXa ra elprj 10 pidva, /cat idv p.rj pLerd rov ^oXov rov Trpwrov dp^iqraL yevvdv, ovKert yewd ro Trapdnav ovrtos irrl^ piiKpod e^erat rod^ dyovov etvai ro acopia rdjv ovcov. opLoiois Se /cat d Ittttos' ev(f>vr]s ydp TTpos ^ yfv- PSYZ* : yiv- vulg. ^ em om. Z. ^ rov P, Platt : to vulg.

" i.e., a mare ; cf. H.A. 577 a 13, 28. * According to H.A. 577 a 18, this happens at the age of 2i years ; see also 545 b 20.



cold quarter. For this reason they do not put the jackasses to the females at the equinox, as is done with horses, but at the time of the. summer solstice, so that the asses' foals may be bom when the weather is warm. (Since the period of gestation in both horse and ass is a year, the young are born at the same season as that when impregnation takes place.) As has been said, the ass is by nature cold ; and a cold animal's semen is, of necessity, cold like itself. (Here is a proof of it. If a horse mounts a female " which has been impregnated by an ass, he does not destroy the ass's impregnation ; but if an ass mounts her after a horse has done so, he does destroy the horse's impregnation - because of the coldness of his own semen.) Thus when they unite \\'ith each other, the impregnation remains intact by reason of the heat resident in one of the two, \iz., that of the horse, whose secretion is the hotter. Both the semen from the male and the matter supplied by the female are hotter in the case of the horse ; with the ass, both are cold. So when they unite - either the hot one added to the cold, or the cold added to the hot - the result is (a) that the fetation which is formed by them continues intact, i.e., these two animals are fertile when crossed with each other, but (b) the animal formed by them is not itself fertile, and cannot produce perfect offspring.

Besides, both horse and ass have a general natural disposition to be infertile. I have already mentioned several points about the ass, and another is that unless it begins to generate after the first shedding of teeth, ** it never generates at all ; so close does the ass come to being infertile. It is the same >\ith the horse ; it is naturally disposed to be infertile ; all K 257

748 b

ARISTOTLE rT]v ayoviav, Koi toctovtov AeiVei rov ayovo^ elvai oaov TO yeveadai ro Ik tovtov i/jv)(p6r€pov rovro 0€ yiverai, orav {^tx^T] '^fi "^^^ ovov cLTTOKpiaei. kol 15 o ovos Se (LaavTcos fiiKpov Seiv Kara rov oiKeZov (TvvBvaaflov dyovov yevwa, ajare oTav Trpoayivrirai TO TTapa (f)vaiv, el rare ivos pioXis yewrjTLKov i^ (xAAtjAcdv ■^v, to €K rovTCov €Ti jLiaAAov ayovov /cat TTapa (f)vaLv ovdevos heijaei rov dyovov elvai, dAA' e^ dvdyKTjs ear ai dyovov.

20 Hvfi^atveL Se /cat to, crctj/Ltara to, rcov rjfiiovcov jxeydXa yiveadat hid ro rrjv dTTOKpiaiv rrjv els rd Karafii^via rpeneadat els rrjv av^rjoiv. eTrel S' evtavcrto? o roKeros rcov roiovrcov, ov pLovov avXXa^elv Set rrjv -qp-lovov dXXd /cat eKdpexpai' rovro S dhvvarov p,r] yivopievcov Karap,rjviojv. rats S' 25 rip.Lovoi's ov ytverai, dXXd ro piev dxp^jctrov pierd rov TTepirrcjpiaros rov e/c rr^s Kvareojg eKKpiverai [hiorrep ovhe rcov dpOpatv ol r^piiovoi ol dppeves 6a(f)paLvovraL rwv drjXeLcbv, coairep rdXXa rd picovv)(0-, dAA' avrov rov TrepirrcopLaros) , rd S' dAAa rpeTTerai els rrjv rov awpLaros^ av^rjaiv /cat to pieyedos. ware avXXa^elv piev evSex^ral TTore rrjv 30 ^T^Aetav, oTTep -rjSrj (f)aiverai yeyovos, iKdpeijjai he /cat e^eveyKelv els reXos dSwaTov. o 8' dpprjv TTore yewrjaeiev dv 8td re ro deppiorepov elvai rov di^Xeos (f>vaeL ro dppev, /cat Std ro pirj avpL^dX ^ Tov awftaros P, Platt : cm. vulg'.

" These two statements are of course of general validity, 258


that is wanting to make it such is that its secretion should be colder, and this occurs when it is united with that of the ass. In the same way the ass comes ^vithin an ace of generating infertile offspring even when it mates with its owti kind ; so that when there is the additional factor of unnatural mating beside the difficulty it has in producing even a single young one in the normal way, the resultant offspring is still more infertile and unnatural ; in fact, it will lack nothing to make it completely infertile, and ^\1ll be infertile of necessity.

Furthermore, female mules grow large in size. This is because the secretion intended for the menstrual flow is diverted to produce growth. And since the period of gestation in such animals lasts a year, the female mule not only has to conceive but has to nourish the embryo all that time ; and this is impossible unless menstrual flow is being produced. None is produced in mules : the unserviceable part of the nourishment is passed out together \vith the residue that comes from the bladder (which explains why male mules do not smell at the pudenda of the females as the other solid-hoofed animals do, but at the residue itself) ; the rest of the nourishment is diverted to growth of the body and to size. Hence although it is possible for the female to conceive occasionally - and indeed the fact is estabhshed that this has happened - it is impossible for her to nourish an embryo for the full period and bring it to the birth. The male may occasionally generate (a) because " the male is by nature hotter than the female, and (b) because the male does not contribute any corporeal and are cited here to explain how the male mule may be able to generate.

ingredient to the mixture. The final result which is produced is a ginnos.'^ This is a deformed mule, for ginnoi are produced also from the horse and the ass when the fetation gets diseased in the uterus, the ginnos being comparable to the metachoiron which occurs among smne, since in that case too it is the offspring which has been deformed in the uterus that is called a metachoiron : any pig may happen to be born thus deformed. Human dwarfs too are formed in a similar way : they too become deformed in their parts and stunted in size during the time of gestation, and thus are comparable with metachoira and ginnoi.

oflfspring which sometimes result from the union of male and female of one and the same species. For metachoira see also 770 b 7.

Book III

We have spoken about the sterihty of mules, and I about the animals which are vi\iparous both exter- animau^^ nally and internally. We now pass on to those (continued;. blooded animals which are oviparous. The pheno- "P"* • mena of generation here are on the one hand similar to those which obtain in the animals that walk," so that the same statement will serve for all of them ; on the other hand, these animals exhibit certain differences not only as between themselves, but also when compared ^vith the animals that walk. Their generation is the result of copulation, i.e., of the emission of semen into the female by the male : this appUes to all of them, of course. But beyond that there are variations : (a) Birds produce a perfect * egg with a hard shell (unless it be deformed by disease). All birds' eggs are of two colours, (b) The Selachian fishes, as I have often repeated, are internally o\'iparous but bring forth their young aHve, after the egg has moved from one position in the uterus to another. Their egg is soft-shelled and of one colour only.*^ The fish known as the fishingfrog '^ is the only one in this class that is not internally viviparous. The cause of this will have to be stated later.* (c) All other fishes that are oviparous produce an egg of one colour only, but this egg is imperfect - its growth takes place away from the parent, and the Cause concerned '^ is just the same as for ' those eggs which are perfected -v^ithin the parent.

I have already spoken about the uterus of these animals ; I have said what are the differences they show, and what are the Causes. Thus, some of the %-iviparous animals (the Selachian fishes) have the uterus high up towards the diaphragm.^ others (the animals which are both internally and externally vi\iparous, such as man, horse, and all such animals) have it down by the pudenda. And of the oWparous animals some (such as the oviparous fishes) have it low down, others (such as the birds) have it high up.

Fetations arise in birds spontaneously as well (as (i.) Birds in the normal way) ; some people call them ^\"indeggs or zephyria.'^ They occur in those birds ^ which are neither good fliers nor crook-taloned but which are prohfic* The reason is : (a) these have a great deal of residue, whereas in the crook-taloned birds this secretion is diverted to produce wings and vnng feathers and their body is small f and solid and hot ; and (6) the menstrual secretion and the male semen are residue ; therefore, as both feathers and semen alike are formed out of residue. Nature cannot pro\ide a large supply for both purposes. And it is for this same cause that the crook-taloned birds do not indulge much in copulation and are not very prohfic, whereas the heavy birds and those fliers which have bulky bodies (such as pigeons and the like) do so. In those birds which are heavy and are not fliers, such as common fowls, partridges, and the like, a great deal of this residue is formed, and that is why their males copulate frequently and their females emit a great deal of matter ; also, some birds of this sort lay many eggs, some lay many times ; thus the common fowl, the partridge and the ostrich lay a large number ; whereas the pigeon family do not lay a large number, but lay many times, the reason being that the last-named stand midway between the crook-taloned birds and the heavy birds ; they are fliers, like the former, and have a bulky body, hke the latter. The result is : (1) As they are fliers, the residue is diverted to their wings ; hence they lay but few eggs ; (2) they are bulky in build, their stomach is hot and very good at concoction, and, in addition, they can easily get their food, whereas the crook-taloned birds have difficulty in getting it ; hence they lay often.

Small birds, too, copulate frequently and are very prolific, just as some small plants are : the material which might produce increase of bulk turns into seminal residue. On this account the Adrianic fowls " are extremely prolific ; as they are small in size, the nourishment is used up for the production of offspring. Also, low-bred birds are more proUfic than high-bred ones,*" because their bodies are more fluid and more bulky, whereas those of the highbred birds are leaner and more soUd," this being the kind of body in which a thoroughbred and highspirited temper tends rather to make its appearance ; also the thinness and weakness of their legs contribute towards making these birds prone to copulation and prolific - and this applies also to human beings : the nourishment which was intended for the legs is in such cases diverted to the seminal residue : what Nature takes away from one place she puts on at the other. The crook-taloned birds, on the other hand, have strong feet, and their legs are thick : this is due to their manner of life ; thus on account of all these causes they do not copulate much nor are they very prolific. The kestrel is the most prolific of them, for this is practically the only one of the crook-taloned birds which drinks, and the fluid, both that which is innate and that which it gets from without, is productive of semen when combined with the heat which is present in it. Even this bird does not lay many eggs ; four at the most.

The cuckoo lays but few eggs although it is not a crook-taloned bird, because it is cold by nature (as its cowardice * clearly shows), whereas an animal that is abundant in semen must be hot and fluid. That it is cowardly is showTi by the fact that all other birds chase it and that it lays its eggs in other birds' nests.

Most birds of the pigeon kind usually lay a couple of eggs. They are neither one-egg birds (there is no one-egg bird beside the cuckoo, and this sometimes lays two), nor do they lay a large number ; but they lay often, producing two, or three at the most, generally two, as these numbers are intermediate between one and many.

The actual facts make it clear that in the prolific birds the nourishment is diverted to the semen. Most trees, if they have borne an excessive amount of fruit, A^-ither away when the 'crop is over, when no nourishment is left over for themselves ; annual plants, as it seems, have the same experience, e.g., leguminous plants, corn, and the rest of that sort. The reason is that, as they belong to a kind which produces a great deal of seed, they use up all their nourishment for semen (seed). Some fowls, too, after having laid excessively - as many as two eggs in a day - have died after performing the feat. The birds and plants alike become completely exhausted, and this condition is simply one of excessive evacuation of residue. It is responsible for the sterility which besets the lion in the latter part of its life. To begin with, the lion " will produce five or six cubs in a Utter, then four the next year, next time three, then two, after that one, and then none at all, which suggests that the residue is being used up and that the semen is diminishing as the prime of life abates.

We have now said which are the birds that produce wind-eggs, and what sorts of birds are prolific and not prolific, together with the causes thereof.

Why are wind-eggs formed ? As has been said Wind-eggs. earlier, their formation is due to the fact that though seminal matter is present in the female, with birds no discharge of the menstrual fluid take place as it does with the blooded Vivipara ; in all of the last-named it does take place, and it is greater in some, smaller

in others, and, in some just enough to serve as an indication." Similarly, there is no discharge in fishes, any more than in birds : and therefore in fishes too, [just as in birds,] fetations arise without previous copulation, though they are less obvious ; that is because their nature is colder. What corresponds to the secretion of the menstrual fluid which occurs in viviparous animals arises in birds at the times proper for that residue, and as the region by the diaphragm is hot these fetations reach perfection in respect of size, though for the purpose of generation they are imperfect, both in birds and fishes, \\"ithout the semen of the male. The cause of these things has been given earher. Wind-eggs are not formed in the birds that are fliers ; the reason why this is so and why birds of this sort are not very prolific layers is one and the same * : in the crook-taloned birds the residue is scanty, and they need the male to give the impulse for the discharge of the residue. The wind-eggs are formed in larger numbers than the ones which are fertile but they are smaller in size ; both facts are due to one and the same cause : they are smaller in size because they are imperfect, and they are more in number because their size is smaller. They are less pleasant to eat because they are more unconcocted, for that which has been concocted ' always makes the more tasty morsel.

Now it has been sufficiently established by observation that neither in birds nor in fishes do the fetations attain perfection for the purpose of generation apart from the males ; with regard to fetations being formed apart from the males in fishes as well, this has been observed, though to a less extent, to occur, but it has been noticed most in the freshwater fishes." Some of them, as we can see, have eggs from the very outset, as is recorded in the Researches.^ Speaking generally, in birds at any rate even the impregnated eggs usually do not grow unless the hen is trodden continually. The reason for this is, that, just as in the case of women intercourse with the males draws down the discharge of the menstrual flow (since when the uterus has been heated it draws the Uquid and the mouths of the passages are opened), so with birds : the same thing occurs ; the menstrual residue advances little by little. It is not discharged externally because there is not much of it and the uterus is high up towards the diaphragm, but it runs down and collects in the uterus itself. This liquid, of course, which percolates through the uterus, makes the ^gg grow, just as that which passes through the umbilical cord makes the embryos of Vi\ipara grow, for when once the birds have been trodden, they all continue almost always to have eggs, albeit quite small ones. In \iew of this, some people are in the habit of saying that windeggs are not formed (independently) either, but are merely reUcs of an earlier impregnation. This however is untrue. It has been sufficiently established by observation that they have been formed in chickens and gosUngs without impregnation. x\gain, when the female partridges " which are taken out to act as decoy-birds smell the male and hear his note, those which have not been trodden by a male become full of eggs and those which have already been trodden at once lay their eggs. The reason why this happens is the same as in the case of human beings and quadrupeds : if they are in heat, some emit the semen at the mere sight of a female, others at a slight touch. Birds of this sort are by nature inclined to frequent intercourse and have abundance of semen, so that when they are in heat the impulse they need to set them off is small, and emission quickly takes place ; the result is that in those which have not been impregnated -s^ind-eggs take shape, and in those which have been impregnated the eggs quickly grow and reach perfection.

In the group of animals which lay their eggs externally, birds produce their eggs in a perfected state, fish in an imperfect state ; but fishes' eggs continue and finish their growth apart from the parent, as indeed I have said earlier. The reason for this is that the fish tribe is very prolific ; therefore it is impossible for a large number of eggs to reach perfection within the animal ; hence they are laid externally. Their discharge is quickly effected, for in the externally oviparous fishes the uterus is near the genital parts. , Birds' eggs are double-coloured, but all fishes' eggs Difference are single-coloured. The cause of the two colours in yoi)^|*^ birds' eggs can be seen from the specific character ^ white. of each of the two parts, the white and the yolk. The secretion (for the egg) is formed out of the blood [(no bloodless animal lays eggs)], the blood, as I have often stated, being the matter for animal organisms. One part of the egg, the hot part," is closer to the form of the developing creatures ; the other, the more earthy part, supplies the wherewithal for building up the bodily frame and is further removed from the form.** That is why in the case of all doublecoloured eggs the young animal gets its " principle of generation from the white, because hot substance is the place where the soul-principle is to be found, while it gets its nourishment from the yolk. With those animals, therefore, whose nature tends to be hotter than others we find there is a clear distinction between the part from which the " principle " is formed and the part from which the nourishment is derived : the one is white, the other yellow, and there is always more of the pure, white part than there is of the earthy, yellow part. With the animals that are less hot and more fluid, there is more yolk in the egg and it is more fluid. This occurs in the case of the marsh-birds, since they are more fluid and colder in their nature than the land-birds, so that the eggs of such birds contain a great deal of what is called yelk (lekithos) and it is less yellow, because the white is less distinctly separated from it. Pass on a further stage to those oviparous animals which are cold in their nature and also still more fluid (the fish tribe answers to this description), and in their eggs the white is not distinct at all ; this is due to their small size and to the abundance of the cold and earthy matter. And that is why all fishes' eggs are singleyolk ; and it was again Harvey who demonstrated that the " cicatricula " was the point of origin of the embryo, " the first Principle of the Egge." coloured - they are white, judged by the colour of ordinary yolk ; yellow, judged by ordinary white. Not only the eggs but also the wind-eggs of birds have this double colouring, because they contain that out of which each of the two parts is to come (the part from which the " principle " arises and that from which the nourishment is derived), although they are imperfect, i.e., they lack the male factor ; since, as we know, wind-eggs become fertile if they are impregnated by the male ^^^thin a certain time. The cause of the double colouring is not the two different sexes (as if the white were derived from the male and the yolk from the female) ; both alike are derived from the female, and the real difference is that one is cold and the other hot. So then, in cases where a good deal of the hot constituent is present, the hot substance is separated from the cold ; but if there is not much of it this cannot occur ; and that is why the fetations of such animals are single-coloured, as I have said. All that the semen does is to " set " the fetations, and that is why in birds the fetation is small and white in appearance at first, but completely yellow as it advances and more bloodlike matter is continually being mixed in with it ; finally, as the hot substance separates off, the white takes up its position around on the outside " evenly in every direction, just as when a liquid boils. \ill get too httle, and some too much ; and too much heat will make them turbid, by causing them to putrefy, as it were. Nevertheless, the same thing occurs with the crook-taloned birds, although they lay but few eggs ; out of two eggs, one mil often turn rotten (ourion), and pretty well always one out of three. They are hot in their nature, and they cause the fluid in the eggs as it were to boil over. The yolk and the white, of course, are of an opposite Deveiopnature to each other. Yolk congeals in frosty j^cubftlon.^ weather,^ and becomes fluid when heated ; hence it becomes fluid when it is concocted in the earth or by means of incubation," and in that condition it becomes nourishment for the animals that are taking shape. When subjected to fire, or roasted, it does not become hard, because it is by its nature earthy in the same way that wax is ; and that is the reason why, when eggs are overheated, [unless they are from a liquid residue] ^ they become serous, and turn rotten (puria). The white, on the other hand, does not congeal as a result of frost, but tends rather to become fluid (I have given the reason earlier) ; and when subjected to fire, it becomes solid. This is why, when it is concocted in connexion with the generation of the young animals, it thickens ; for it is the white out of which the animal forms and develops, while the yolk becomes nourishment for it, and is the source from which the parts as they are formed at the various stages derive their growth. That, too, is why the yolk and the white are kept distinct and separate from each other by membranes, as having a different nature from each other. For an exact account of how these stand to one another both at the beginning of the process of generation and during the process of the young animals' formation, also for an account of the membranes and umbilical cords, what is \^Titten in the Researches should be studied ; for our present inquiry it is sufficient that thus much should be clear, viz., that once the heart has been formed (this comes first of all) and the Great Blood-vessel has been marked off from it, two umbiical cords extend from heated, it becomes soft ; and so when it is subjected to fluid, it turns rotten owing to the excess of fluidity " (c/. 753 a 34, above).

this blood-vessel, one to the membrane which surrounds the yolk, the other to the chorion-Hke membrane which surrounds the animal on all sides ; this one goes round inside the membrane of the shell." Through one of these cords the embryo receives the nourishment from the yolk ; and the yolk increases in bulk, becoming more fluid as it is heated,* since the nourishment, being corporeal, must be available in fluid form, just as it must for plants, and the embryos that are in process of formation, either within the egg or within the uterus, are to begin with living the life of a plant, since their first growth and nourishment they obtain through being fastened on to something. The other umbilical cord extends to the chorion which surrounds the embryo. In the case of the animals that are produced oviparously, we should think of them (a) as having the same relationship to the yolk as the viviparously formed embryos have to the mother, so long as they are within the mother ; for since the nourishment of the oviparously formed embryos is not completed within the mother, when they leave her they take a part of her out \\ith them ; (h) as having the same relationship to the outermost - the bloodlike - membrane as the other embryos have to the uterus. Also, the eggshell which encloses the yolk and the chorion gives the egg an envelope analogous to the uterus : it is as though you were to envelop both a viviparously produced embryo itself and its mother entire. '^ The reason why this is so is that the embryo must be in the uterus, i.e., in contact with the mother. Very well then : in the case of the viviparously produced animals, the uterus is in the mother ; but with the oviparously produced ones it is the other way round - the mother is in the uterus, as you might say, because in this case that which comes from the mother [the nourishment] is the yolk. The reason is that the embryo's period of nourishment does not reach completion within the mother.

As the embryos grow, the first of the umbilical cords to collapse is the one which connects to the chorion, because that is the point at which the young animal v,i\\ have to make its way out ; the rest of the volk and the cord which connects to it collapse later, because the young animal must have nourishment immediately it is hatched, as it is neither nursed by its mother nor able immediately to get nourishment by means of itself. That is why the yolk goes inside it together with the umbilical cord and the flesh grows round it.

Such is the manner in which animals which are brought to birth out of perfect eggs are produced in the case of those birds and fishes which lay a hardshelled egg. The points mentioned are to be seen more clearly in the larger animals ; in the smaller ones they are not so obvious owing to the small bulk of the animals.

Another member of the Ovipara is the tribe of III fishes. (ii.) Fishes: Those fishes whose uterus is low dovvTi lay an imperfect egg. The cause of this I have stated prexiously." The Selachian fishes as they are called produce a (a) Seiachia perfect egg internally though they are externally viviparous, except for one which they call the fishingfrog ^ ; this is the only one that lays a perfect egg externally. The cause of this is the nature of its body. Its head is several times as large as the rest of its body, and, besides that, spiny and extremely rough ; so that the reason why it does not take its young ones in afterwards " is also the reason why it does not produce them alive at the outset : just as the size and roughness of its head prevents them from going in, so also it prevents them from coming out. Since, then, the egg of the Selachia has a soft shell (because they cannot make the envelope hard and solid, being colder creatures than birds are), the egg of the fishing-frog is the only one that is hard and stout, so as to keep it safe in the outside world ; the others' eggs are liquid and soft in nature, because they are inside the mother and get their shelter from her body.

The process of generation out of the egg is the same Developboth for the fishing-frogs, which are perfected exter- ^^br/J/^ nally, and for those Selachia which are perfected internally ; and as between the latter and the birds, it is partly similar, partly dissimilar. First of all, they lack the second umbilical cord which extends to the chorion under the surrounding shell, and the reason for this is that they have not got this shell round them, as it is no use to them, their shelter being provided by the mother ; whereas for eggs that are laid externally the shell is there to act as a protection against injury from without. Secondly, with these, as with birds, the process of generation originates from the extremity of the egg, though not at the place where it is attached to the uterus. A bird's development begins from the pointed end, which is the place where the egg was attached, the reason being that a bird's egg becomes separated from the uterus, whereas the eggs of most, though not all, fishes of this class remain attached to the uterus even when they are perfect. As the young animal develops at the extremity, the egg gets used up (just as in the case of birds and the other eggs that have been released from the uterus), and at the final stage, by which the animal has reached its perfect development, the umbilical cord remains attached to the uterus." The like ^ holds good in the case of those Selachia whose eggs have been released from the uterus, there being some whose egg is released as soon as it is perfected.*^ In view of what has been said, the puzzle may be Differences raised why the processes of generation in birds and gj^^^l^an^" fishes differ in this respect. The reason is that in Seiachia. birds' eggs the white and the yolk are separate, whereas fishes' eggs are single-coloured, the contents being mixed up together throughout, so that there is nothing to prevent the " principle " in them being at the opposite end ; the egg is of similar composition both at the end where it is fastened and at the opposite end, and it is easy for it to draw the nourishment out of the uterus by means of passages which lead from this principle. This can clearly be seen in those eggs which do not get released, for in the case of some of the Selachia the egg does not get released from the uterus, but remains connected as it proceeds downwards to produce the young alive. In these cases, the young animal, after it has reached its perfect development, retains its umbilical cord joined to the uterus when the egg has been consumed. Thus it is plain that during the earher stages also, while the creature was still enveloped in the egg, the passages extended to the uterus. This occurs, as we have said, in the smooth dogfish.* I have now mentioned the respects in which the process of generation of fishes differs from that of birds, and also the causes thereof. Otherwise, they both follow the same course. The fishes have one of the two umbiUcal cords, just as the birds have (in birds it connects with the volk, in fishes with the entire egg, because the fish's egg is all single-coloured and lacks the distinction into white and yolk), and they obtain their nourishment by means of this ; as it gets consumed the flesh in like manner encroaches upon it and grows round it.

I have now described the manner of formation of those fishes which produce a perfect egg internally and are \aviparous externally.

The majority of the remaining fishes are externally IV oviparous ; and all of them except the fishing-frog jf\^^^* produce an imperfect egg. The reason for this exception I have given earlier. I have also given the reason whj- the others produce imperfect eggs.*^ So far as the process of formation is concerned, the development from the egg follows the same lines as the internally oviparous Selachia, except that they start very small and grow very quickly, and the outside of the egg is harder. The growth of the egg is like (that of) larvae, for those animals which produce larvae produce something small to start with, which grows by its own means and not in virtue of any attachment. The reason for this is on a par \\ith the reason why yeast grows. Yeast, hke these, is small in bulk to start A\ith anH gets larger : this growth is due to its more sohd portion turning fluid, and the fluid turning into pneuma.^ This is the handiwork of the soul-heat '^ in the case of animals, of the heat of the humour blent with it in the case of the yeast. Eggs thus grow of necessity on account of this cause (/.e., they contain a yeast-like residue), but also they grow /or the sake of rvhat is better, since it is impossible for them to obtain all their gro^\â– th in the uterus owing to the prolific habit of these animals. That is why the eggs are quite small when they are discharged and why they grow quickly : they are small because the uterus is not roomy enoug-h to hold so large a number of eggs, and they grow quickly to prevent the destruction of their kind which would occur as a result of their spending a long time over the growing period of their formation. Even as it is, the majority of the fetations that are laid externally get destroyed. That is why the fish tribe is proHfic : Nature makes good the destruction by sheer weight of numbers. There are also some fishes, such as the one known as belone,^ which burst asunder owing to the size of the eggs, the fetations of this fish being large instead of numerous ; here Nature has taken away from their number and added to their size.

I have now described the growth of eggs of this sort and h«tve stated the Cause of it.

Synffnuthus acus. In tliis group (of which the well-known " sea-horoc " is another member) the male incubates the eggs in a brood-pouch formed by the pelvic fins. Aristotle correctly states at H.A. loc. c'lt. that the fisb is none the worse for its " bursting asunder."

A proof that these fishes as well as the others V produce eggs is that even the viviparous fishes, such theories"* as the Selachia, produce eggs internally at the first (i) Fish are stage. Why is this a proof ? Because " it is plain that ous and do the nhok of the tribe of fishes is oviparous. At the l^^^^^ same time, no eggs of this sort reach perfection, - i.e., eggs of species where both males and females exist, and which are formed as the result of copulation - unless the male sprinkles his genital fluid (milt) upon them ; though there are some people who hold - â– incorrectly - that all fish are female apart from the Selachia. Their \\e\v is that the females differ from what are reputed to be males in the same way as those species of plants in which one tree will bear fruit and another \vill bear none (e.g., the olive and oleaster, the fig and caprifig).*^ They say it is just the same with fish, except in the case of the Selachia, where they do not dispute the point. But as a matter of fact there is no difference as regards their seminal parts between males of the Selachian fishes and males which belong to the oviparous group, and semen can clearly be seen oozing out from males of both groups at the proper season. Also, the females have a uterus ; but if the whole tribe of fishes really were female, some of them being unproductive of young," then not only those fishes which lay eggs but all the others as well ought to have a uterus, though no doubt different in form from that of the ones which lay the eggs [hke female mules in the class of bushytailed * animals]. In fact, however, while some fish have a uterus, others have seminal parts, and this distinction is found in all species except two, the erythrinus and the channa'^ : some have seminal parts, others have an uterus. The puzzle which makes people put forward this theorj- is easily solved when we hear what the facts are. These people allege - and here they are quite correct - that none of the animals which copulate produces many young, for of all the animals which generate out of themselves either perfect animals or perfect eggs, none is so proUfic as the oviparous fishes, the number of their eggs of course being something enormous. But this point they have overlooked : eggs of fishes do not behave in precisely the same way as those of birds. Birds, o\iparous quadrupeds, and any o^^parous Selachians there may be,* produce a perfect egg, and once it has left the parent it grows no further ; fish on the other hand produce imperfect eggs, which do grow after they have left the parent. Furthermore, the same occurs in the case of the Cephalopods and Crustacea ; and these creatiu-es can actually be seen copulating, for with them copulation goes on for quite a long time, and it is plain here that one is male and the other has a uterus. Also, it would be odd if this characteristic *" were present in a portion of the group and not in the whole of it, just as male and female are found in all the ^'i\ipara. The reason for the ignorance of those who make the statement mentioned is that the differences in the copulation and generation of the various animals are manifold, but they are not obWous, and our friends base their study on a few instances and think the same holds good for all.

So too those who assert that female fishes conceive (2) The as a result of swallowing the male's semen have Jfrnii^" failed to notice certain points. Thus in fact milt is present in the male and eggs in the female at about the same time, and the closer the female is to laying the eggs the more abundant and the more fluid becomes the milt in the male. And just as the growth of the milt in the male and that of the egg in the female is simultaneous, so also the emission of them both is simultaneous : the females do not lay all their eggs at once, but a few at a time, and the males do not emit all their milt at once. All this is as we should expect. In the bird tribe, eggs are in some instances present without impregnation, though such eggs are not numerous and they occur but seldom, most eggs being the result of impregnation. Exactly the same occurs in fish, though to a smaller extent. These spontaneous eggs, both in birds and fish, are infertile unless (in those species where there are males as well) the male sprinkles them. With birds, o\^ing to the fact that the eggs have reached a perfected state when they are discharged, this must happen while they are as yet within the mother ; but the eggs of fish, without exception, are imperfect when discharged and continue their gro\^'th afterwards ; hence, even if the egg has come into being as the result of impregnation, still, the ones which persist safe and sound are those which get sprinkled after they have been discharged ; that is where the milt of the males is used up, and that is why it comes down in smaller quantities at the same time that the production of eggs by the females diminishes, for the males always follow up the eggs and sprinkle them as thev are laid.

Thus fish are male and female, and they copulate, all of them (unless there be some species ° where the sexes are not distinct), and no fish at all of any sort comes into being apart from the semen of the male.

Another point which helps to deceive these people is this. Fish of this sort take only a very short time over their copulation, with the result that many fishermen even never see it happening, for of course no fisherman ever watches this sort of thing for the sake of pure knowledge. All the same, the copulation has been observed. The fish copulate in the same way as dolphins do, by placing themselves alongside of each other [that is, those which are (not) hampered by the tail]. Dolphins, however, take longer to relieve * themselves, whereas fish of this sort do so quickly. The fishermen do not notice this, but they do notice the swallowing of the milt and eggs by the female, and so they join the chorus and repeat the same old stupid tale that we find told by Herodotus " the fable-teller, to the effect that fish conceive by swallowing the milt. It never strikes them 'that this is impossible, but of course it is, because the passage whose entrance is through the mouth passes do-s^-n into the stomach, not into the uterus, and whatever goes down into the stomach must of necessity be turned into nourishment, because it undergoes concoction. The uterus, however, as we can see is full of eggs ; so we ask, how did they find their way there ? It is the same with the generation of birds. Thus VI there are those who say that ravens and ibises unite ^rroneous by the mouth, and that one of the quadrupeds, the about weasel, brings forth its young by the mouth. This is, ^^frd"**" in fact, alleged by Anaxagoras and some of the other «*«physiologers ; but their verdict is based on insuflicient e^^dence and inadequate consideration of the matter. (1) So far as the birds are concerned, thev ' have reasoned themselves into an erroneous conclusion, since the copulation of ravens is seldom witnessed, whereas they are frequently observed uniting with each other by their beaks, which is something that all birds of the raven family do, as is plain for everyone to see in the case of domesticated jackdaws. Precisely the same thing is done by birds of the pigeon family ; but as their copulation is plainly observable as well, they have not succeeded in quaUf^ing for the heroes' part in this amazing storv'. Actually, birds of the raven group are not unduly sexual : it is one of the groups that produce but few young ; still, like other birds, they have been observed in the act of copulation. It is odd, however, that our friends do not reason out how the semen manages to pass through the stomach and arrive in the uterus, in view of the fact that the stomach concocts everything that gets into it, as it does the nourishment. Besides, these birds have a uterus, just like other birds, and eggs can plainly be seen up towards the diaphragm. (2) The weasel, too, like other quadrupeds, has a uterus of exactly the same sort as theirs ; and how is the embryo going to make its way from that uterus into the mouth ? This notion is really due to the fact that the weasel produces very tiny young ones (as do the rest of the fissipede animals, of which we shall speak later)," and that it often carries them about in its mouth.

(3) There Ls another silly and extremely wrongheaded story which is told about the trochos * and the hyena, '^ to the eifect that they have two pudenda,, male and female (there are many who assert this of' the hyena ; Herodorus of Heraclea ** asserts it of the trochos), and that whereas the trochos impregnates itself, the hyena mounts and is mounted in alternate years. In some localities, however, there is ample opportunity for inspection, and the hyena has been observed to possess one pudendum only ; but hyenas have under the tail a Une similar to the female pudendum. Both male and female ones have this mark, but as the males are captured more frequently, casual inspection has given rise to this erroneous idea.* •* Heraclea Pontica, a colony of Megara, on the south shore of the Black Sea, about 100 miles east of the Bosporus. Herodorus (fl. c. 400 b.c.) was the father of the sophist Bryson (both are mentioned at H.A. 563 a 7 and 615 a 9). He wrote a History of Heracles, which seems to have contained a great variety of matter. • See add. note, p. 565.

1 have now sa^-^^d-eggs become fertile," and with regard to t^npf^rl bv t>»»^ vix-iJix^rc.rJ'^K/zle VII may be raised, what the Cause can possibly be why I^^°s.^ neither the females of Selachian fishes are seen shedding their fetations nor the males their milt, whereas the males and females are observed so doing in the case of non-viviparous fishes. The reason is that in general the class of the Selachians is not rich in semen : and also in the females the uterus is up towards the diaphragm." Of course males of one class differ from males of another, and females similarly ; and the fact is that the Selachians yield less semen than most. With the oviparous fishes, the males shed their milt, just as the females lay their eggs, because there is such an abundance of both ; the males have more milt than the amount which suffices for copulation, because Nature prefers to expend the milt in helping to enlarge the eggs after the female has laid them, rather than in constituting the eggs at the outset. This remark is explained by what has been said both in our earlier discussion and also not long ago, viz., the eggs of birds are perfected inside the parent, but the eggs of fish outside. In a way, fish resemble the larva-producing animals, for the latter deposit a fetation which is even more imperfect still. The perfecting in both cases, birds' eggs and fishes', is accomplished by the male. With birds this is done within the parent animal, because a bird's egg is perfected inside ; vriih fishes, outside, because the egg is in an imperfect state when it is deposited outside. The upshot however is the same in both cases.

In birds, wind-eggs become fertile," and eggs Wind-eg previously impregnated by the treading of one sort of cock clxange their nature to that of the cock which treads the hen later ^ : and also, where one and the same cock is concerned,*' if he has left off treading the hen and the eggs are not growing on that account, he makes them grow quickly when he resumes the treu-ling. This however cannot happen at any and every period ; the treading must take place before the change occurs when the white of the Ggg becomes separate. In the case of fishes' eggs there is no such point fixed, but the males sprinkle *hem without delay to keep them in sound condition. The reason is that fishes' eggs are not doublecoloured : that is why in their case there is no such fixed time as there is for birds' eggs. This situation is what we should expect, for once the white and the yolk have been distinctly separated from each other, they already '^ possess the principle that comes from the male,* since the male contributes [towards] this. Thus wind-eggs attain to generation in so far as it is possible for them to do so. It is impossible for them to be perfected to the point of producing an animal, because sense-perception ^ is required for that ; the nutritive faculty of the Soul, however, is possessed by females as well as by males and by all living things, as has been said repeatedly ; hence the egg itself, regarded as the fetation of a plant, is perfect, but regarded as the fetation of an animal it is imperfect. If there were no such thing as a male in the class of birds, the egg would have been formed as it is in fishes, supposing there really is some species which generates without a male ; though I mentioned earlier ° in this connexion that this has not yet been sufficiently observed. Actually, however, both sexes exist in all species of birds ; so that, qua plant, the >\ind-egg has reached perfection (and that is why it does not change any more after impregnation),^ qua non-plant, on the other hand, it has not reached perfection, and nothing else results from it, since it has been formed neither as a plant simply and directly '^ nor as an animal by means of copulation. As for eggs which are the result of copulation, however, but which have been distinguished into white and yolk, these are formed according to the male which impregnated them first, since by that time they possess both the required principles.** The production of their young is accomplished in VIII the same manner by the Cephalopods - sepias and l^- ^lood i_ 1-1 11 i" /-I f • 1 1 lessanimals.

the hke- and by the Crustacea - caraboi * and the (i.) Reprocreatures akin to them. They too lay eggs as a cephaio-"' result of copulation ; many instances have been pods and observed of the male uniting with the female. So here we have another score on which we can con\ict of a lack of scientific accuracy those who allege that all fish are female and produce eggs without copulation. What an extraordinarj' thing, to hold that Cephalopods and Crustacea lay eggs as a result of copulation, but fish ^v•ithout copulation I Or alternatively, if they were not already aware that the other creatures copulate, then it just shows how ignorant they are. The copulation of all these creatures takes quite a long time, just as that of insects does, which is not surprising, because they are bloodless, and therefore cold in their nature.

In the sepias and calamaries the eggs appear to be two in number, because the uterus is di\ided and appears to be double. The octopuses appear to have a single egg ; the reason is that the shape of the uterus is round and spherical in form, and when it is full the cleavage is not ob\'ious." The caraboi also have a double uterus. All these animals as well deposit the fetation in an imperfect condition, and for the same cause. Females of the caraboid group deposit their eggs on to themselves ; that is why they have larger flaps than the males - in order to protect the eggs ; the Cephalopods lay their eggs clear of themselves. The male Cephalopods sprinkle their milt over the females, just as male fishes do over the eggs, and it becomes a glutinous mass. Nothing of the kind has been observed to occur with the caraboids, nor should we expect it, because the fetation is situated under the female and is hardskinned, and both these eggs and those of the Cephalopods pursue their growth after they have left the parent, just as the eggs of fishes do.

The sepia while in process of formation is fastened to the egg by its front part, which is the only possible place, because its front and back parts face in the same direction (in this respect it is unique). For a figure showing the way in which it is situated during the process of formation, the Researches " should be consulted.

We have now spoken about the generation of the animals that walk, fly and s\vim. Following the IX plan we have laid down, there remain the Insects and the Testacea to be discussed. We wiM deal wWh the Insects first.

I said earlier that some Insects are formed by (ii.) Repromeans of copulation, others spontaneously ; further, insects :° that they produce a larva, and I stated the cause of their so doing. In a way, it looks as though practically all animals produce a larva to begin with, for the fetation in its most imperfect state is something of this sort ; and in all the Mvipara and all the 0\ipara that produce a perfect €:gg, the fetation in its earhest stage is still undifferentiated and is growing, and this is just the sort of thing a larva is. At the next step, some of the 0\ipara produce their fetation as a perfect ^^g,, some as an imperfect one which reaches its perfection after it has left the parent, as I have often stated ^\â– ith regard to fish. In the case of the internally %'i\iparous animals, the fetation, after it has been constituted at the outset, in a way beconjes egghke : its fluid content becomes enclosed in a fine membrane - like an egg with its shell taken off - and that is why a fetation aborted at this stage is known as an " efflux." * Those Insects which generate, generate larvae ; (a) Larrap. and those Insects also which are formed spontaneously and not by means of copulation are, to begin with, formed from an organism of this sort. This is correct, for we are bound to reckon caterpillars ** and the product of spiders as a form of larva. True, some of these, and many belonging to other Insects, would appear to resemble eggs on account of their circular shape ; but our decision must not be determined by their shape nor yet by their softness or hardness (the fetations of some of these creatures are hard), but by the fact that the ivhole of the object undergoes change - the animal is formed out of the whole of it and not some part of it.*" All these larva-like objects, when they have advanced and reached their full size, become as it were an e^gg : the shell around them gets hard, and they remain motionless during this period. This is clearly to be seen with the larvae of bees and wasps, and with caterpillars. The reason for this is that their Nature, owing to its own imperfection, deposits the eggs as it were before their time, which suggests that the larva, while it is yet in gro^^•th, is a soft egg. A comparable thing occurs in the case of all other creatures which are formed independently of copulation in wool'^ and other such material and in water. All of these first have the nature of a larva, then they remain motionless once the covering has solidified round them ; after that the covering bursts and there emerges, as from an egg, an animal which, at this its third genesis,** is at last produced. Aristotle however calls them larvae, and not eggs, at this stage, because according to him the stage which really corresponds to the egg-stage is not reached until later, when the creature becomes immobilized as a " pupa."

perfected. Of these creatures, the winged ones are larger than those that walk.

Another occurrence, which may well cause surprise to manv people, is reallv quite regular and normal. Caterpillars at first take nourishment, but afterwards they cease doing so, the chrysalis (as some call it) being motionless ; so too the larvae of wasps and bees afterwards turn into pupae as they are called [and have nothing of the sort]. This is not abnormal, for an egg also, when it has reached the perfection of its nature, does not grow, whereas to begin with it does grow and takes nourishment, until its differentiation is effected and it has become a perfect egg. Some larvae contain in themselves material from which as they feed on it residue is produced," e.g.. those of bees and wasps ; others get the material from Nsithout, as caterpillars and some other larvae do.

I have no^v stated why it is that it takes a threefold generation ** to produce creatures of this sort, and the cause which, after they have begun as mobile creatures, makes them become immobile again. Also, some of them are formed in consequence of copulation, just as birds, Vi%ipara and the majority of fishes are ; others are formed spontaneously, as certain plants "^ are.

The generation of bees is a great '^ puzzle. If it X is a fact that certain fishes are generated without ^®®^copulation, the same probably occurs among bees as well - or so it seems from appearances. The possible methods are these : Bees must either (a) fetch the offspring ^ from elsewhere (some hold this view) ; in which case the offspring will either have sprung into being spontaneously' or have been produced by some other animal ; or (6) generate the young themselves ; or (c) fetch some and generate some (this, too, is a \'iew held by certain people, who maintain that the young of the drones only are fetched). If they generate the young themselves, this must be done either with or without copulation ; if with copulation, then either (i) each kind generates its own kind,*^ or (ii) one of the three kinds generates the others, or (iii) one kind unites with another kind. WTiat I mean is, e.g., either (i) " bees " are formed from the union of " bees," drones from the union of drones, kings from the union of kings ; or (ii) all the rest are generated by one kind onlv : e.g., by the kings or leaders as they are called ; or (iii) by the union of drones and " bees " (some people of course say that drones are male and " bees " female ; others that " bees " are male and drones female).

We have only to bring before our minds the special and particular facts concerning bees, on the one side, and on the other the facts more generally applicable to other animals, to see that all of these theories are impossible. Suppose they do not generate offspring themselves but fetch them from elsewhere. In that case bees ought to be formed, even if the, bees failed to fetch them away, in those places whence they fetch the seed (semen). For why should a bee be produced if the seed is fetched away, and not if it is left where it is ? Surely it ought to be produced none the less, no matter whether it springs spontaneously to Ufe in the blossoms or whether some animal generates it. Also, if the seed were that of some other animal, then that animal ought to be formed out of it, and not bees. Further, it is reasonable enough that bees should collect honey, for honey is their food ; but it is absurd that they should collect offspring which (a) is produced by some animal other than themselves, and (6) is not food. After all, why should they ? All creatures which concern themselves about young ones take that trouble over what appears to them to be their otvn proper offspring.

Nor is it reasonable to hold that " bees " are female and drones male ; because Nature does not assign defensive weapons to any female creature ; yet while drones are without a sting, all " bees " have one. Nor is the converse \-iew reasonable, that " bees " are male and drones female, because no male creatures make a habit of taking trouble over their young, whereas in fact " bees " do. But generally, since it is apparent that the brood of the drones is produced even when there is no drone present to start with, whereas young "bees " are produced only if the kings are present (and this is why some people say that the brood of the drones are the only ones they fetch from away), it is plain that they are not formed as a result of copulation, either (1) of" bee " vrith " bee " or drone with drone, or (2) of " bee " with drone. And anyway, not only is it impossible that drones are the only ones they fetch in, for the reasons stated, but also it is unreasonable to suppose that a similar thing does not happen in respect of the whole tribe of them." Again, it is impossible that some of the " bees themselves " should be male and some female, since in all kinds of animals the male and the female are different. And besides, if it were so, " bees " by themselves would generate " bees," but in actual fact we see that the brood of " bees " is not formed unless, as they say, " the kings are -within." And here is a point which strikes at either theorj' (that they are produced (o) by the union of " bees " with one another, and (6) by their union with the drones, i.e., by one kind apart from the other, or by the two kinds together with one another) : none of them has ever been seen in the act of copulation, whereas if there had been male and female among them this would often be occurring. The remaining possibility, assuming that they are generated by means of copulation at all, is that the kings unite and so generate them. But, as against this, the drones, as we see, are formed even if no " leaders " are " within " ; and as it is impossible that the " bees " should either fetch in the brood of drones from away or generate them by copulation themselves,* plainly the only possibility remaining is something parallel to what we find occurs in certain fishes " : the " bees " generate the drones -without copulation, i.e., although so far as generating is concerned they are female, yet they contain in themselves the male as well as the female (factor), just as plants do ; and this also is why they possess the organ for self-defence,* for of course it is wrong to apply the term " female " to creatures where no separate male exists.

We find then that this is what occurs in the case of the drones : they are formed independently of copulation. And if this is so, then surely the same argument must apply to the " bees " and the kings ; they too must be generated independently of copulation. Now if we were sure that the brood of the " bees " made their appearance ^vithout the kings being there, then it would follow of necessity that the " bees " as well as the drones are produced from " bees " ^vithout copulation. This however is denied by those whose business it is to look after these creatures. Hence the only possibility left is that the kings generate their own kind and the " bees " as well.

We see then that the manner in which bees are generated appears to be peculiar, in keeping ^nth their extraordinary and pecuUar character. Bees' generating without copulation might be paralleled by the beha\iour of other animals, but their generating some different kind of creature is peculiar and unique, for even erythrinoi and channae generate creatures of the same kind as themselves. The reason is that the " bees themselves " are not generated in the same way as flies and other such creatures, but from a kind which though different is akin to them - they are, of course, generated from the " leaders." Hence their manner of generation is in fact arranged in a sort of proportionate series " ; [thus, the leaders are similar to the drones in size, but similar to the " bees " in possessing a sting ; therefore the " bees " are similar to them in this respect, but the drones are similar to them in size,] for of course the three kinds must of necessity fail to coincide in some respect, unless the same kind is always going to be bound to be generated from each, and this is impossible, because then the whole tribe of them would be " leaders." Therefore the " bees " have been made similar to them in respect of characteristic properties,* [i.e., in \irtue of generating young,] while the drones have been made similar to them in respect of size [and if they had a sting as well, they would be " leaders." As it is, this portion of the puzzle remains, since the leaders resemble both kinds at the same time, the bees in possessing a sting, the drones in size.] "^ But the leaders too must be generated from something ; and since they are generated neither from the bees nor from the drones, they must of necessity generate their own kind as well. [And their cells are the last to be formed, and are not many in number.] ^ So it turns out that the leaders generate their own kind, and another kind as well (viz., the " bees ") ; while the " bees " generate another kind (the drones), but not their own kind ; this they have been deprived of doing. And since any business of Nature's always has an orderly arrangement, on that account necessity requires that the drones shall have been deprived even of generating some other kind. And this is what is found to be the case in actual fact : they are generated themselves, but generate no other creature ; thus the progression of generation reaches its limit at the third term of the series. And this arrangement has been so well constituted by Nature that the three kinds continue ever in existence and none of them fails, though not all of them generate. [Another point about them, which is in accord with what we should expect, is this. In fine seasons, much honey and a large number of drones is produced, in rainy seasons a large number of offspring generally. The reason is that wet conditions produce more residue in the bodies of the leaders, whereas fine seasons do the same in those of the bees, for being smaller in size they have greater need of fine weather.] ° Besides, it is well that the kings, who have, as it were, been made specially for the purpose of procreation, should stay within, released from the drudger}- that has got to be done by somebodv : and that they should be large, since their bodv lias been constituted as it were for procreation, and that the drones should be idle, as they have no weapon for engaging in combat to secure their food, and also on account of the slowness of their bodies. [The be'es, however, are as regards size midwav between the two, for thus they are ser\iceable for active work, and they are workers inasmuch as they support and feed their children and fathers alike.] " Other facts which fit in well are these : (a) the bees attend upon the kings - because the bees are generated from the kings ; since, if nothing of this kind were the case, the facts about their leadership would be lacking in reason ; (h) they allow the leaders to do no work, as being their parents, and they punish the drones, as being their children, because it is a finer thing to punish children and those who have no function to perform.* The fact that the leaders, though few themselves in number, generate a large number of bees looks like a parallel phenomenon to the generation of hons. Lions '^ to begin with generate five, then fewer, finally one, then none at all. The " leaders " generate a multitude to begin with, and later on a few - these are of their own kind,** and though the brood of these is smaller in number, Nature, because she has taken away from their numbers makes up for it by giving them more in the wav of size.

This, then, appears to be the state of affairs with regard to the generation of bees, so far as theory can take us, supplemented by what are thought to be the facts about their behaviour. But the facts have not been sufficiently ascertained ; and if at anv future time they are ascertained, then credence must be given to the direct e\idence of the senses more than to theories, - and to theories too pro\ided that the results which they show agree Avith what is observed." [Another piece of evidence which goes to show that bees are generated A\ithout copulation is that the brood appears to be quite small in the cells of the comb, whereas those insects which are generated by means of copulation (a) spend a long time in intercourse, and (6) quickly bring forth their offspring, which is of the nature of a larva and of considerable size.]

With regard to the generation of the animals that Hornete are akin to bees, such as hornets and wasps/ the "^^^v^ situation is in a way similar in all of them, but the extraordinary features are lacking, and this is what we should expect, because they contain no diWne ingredient as the tribe of bees does. Although the " mother-wasps " as they are called do indeed generate, and mould the first of the cells, it is by copulation with one another that they generate, as their copulation has often been observed. To find out the various differences between each of these kinds of creatures, and between them and bees, the records given in the Researches ^ should be studied.

We have now described the generation of all the Insects, and we have next to describe the Testacea.

The circumstances of the generation of these XI animals also is to some extent similar, to some extent j" cti^ of^ dissimilar, to those of the others. And this is what Tesuc«u we should expect, for compared with animals, they resemble plants, compared with plants, they resemble animals, so that in a way it seems that they are generated from semen, but in another way not ; and in one sense that they are spontaneously generated, in another that they are generated from themselves, or some by the one method, some by the other. In \irtue of the Testacea being in their nature the correlative of plants," no part, or only a small part, of this tribe comes into being in the earth (examples are snails, and any such species there may be besides, but there are not many), whereas many species, of all kinds of shapes, Uve in the sea and similar watery places. The plant tribe, on the other hand, makes very little show - practically none at all, in fact - in the sea and such places, but all members of this tribe grow in the earth. The reason is that in respect of their nature the two tribes stand in a correlative position ^ : the nature of Testacea is removed from that of plants by an interval corresponding to that by which water and fluid matter are better able to support hfe than earth and sohd matter, since Testacea aim at being so related to the water as plants are related to the earth : it is as though plants were a sort of land-shellfish, and shellfish a sort of water-plant.

And it is for some such cause as this that the things Various which grow in the water are more various in shape pro^r\o than those which grow in the earth. It is because various a fluid substance is in its nature more plastic than earth, and not much less substantial ; and this is a characteristic possessed to a marked degree by the creatures in the sea, since fresh water, though sweet (palatable) and nutritious, is less substantial and is cold. Hence, those animals which are bloodless and not hot by nature are not produced in lakes nor in the fresher of brackish waters, except to a somewhat small extent - such as the Testacea, Cephalopods and Crustacea, all of which are bloodless and cold by nature - whereas in lagoons " and near the mouths of rivers they art produced. ** The reason is that they seek both warmth and food together ; and sea-water is fluid and much more substantial than fresh water and it is hot by nature,*^ and it contains a quota of all the parts ** - of fluid, of pneuvia, and of earth - so that it also contains a quota of all the creatures which grow in each of them, because we may sav that plants belong to the earth, aquatic creatures to the water, and land-animals to the air, but the more and less and nearer and further make a surprisingly great difference.^ As for the fourth tribe, we must not look for Fire it in these regions, although there wants to be a kind corresponding to the position of fire in the series, since fire is reckoned as the fourth of the corporeal substances. But always, as we see, the shape and appearance which fire has is not its own ; on the contrary, fire is always in some other one of the substances, for the object which is on fire appears either as air or smoke or earth. No ; this fourth tribe must be looked for on the moon, since the moon, as it appears, has a share in the fourth degree of remove. However, these matters should form the subject of another treatise.

With regard to the Testacea,"^ then : some of them (a) Sidetake shape spontaneously, others by means of the paction? emission of some special substance from themselves, though these too are often formed from a spontaneous composition. We must here apprehend the ways in which plants are generated. Some plants are formed from seed, some from sUps planted out, others by sideshoots (e.g., the onion tribe). Now the last-named is the method by which mussels are formed ; small ones are always growing up by the the salamander, which cannot be destroyed by fire ; the History of Animals passage is, however, excised by A.-\A'. There is a long discussion in Jaeger, Aristotle, 144-14.8, in which the doctrine of fire-animals is involved. Jaeger tries to prove that the doctrine that there were animals that were engendered in fire must have come in one of Aristotle's dialogues {On Philosophy), and by a curious blunder states that it does not come in History of Animals {loc. cit., to which he actually refers) ; but in fact Aristotle's words are yivercu drfpLa ev t(x> irvpi. Jaeger makes no reference at all to the present passage.

side of the original one. The whelks and purpuras and those which, as the phrase goes, are " honeycombers "" emit quantities of slimy fluid emanating as it were from some seminal substance. (We must not, however, consider any of these substances as being semen proper ; instead, we should regard them as sharing in the resemblance to plants in the way already mentioned. And that is why a large number of such creatures is produced when once one has been produced, since, as all these creatures are in fact produced spontaneously as well, pro rata more of them arise if there are actually some * present to start with.) After all, it is reasonable to suppose that there is a surplus portion of residue close by each of the original stock, from which each of the sideshoots springs up. And since the residue is a substance possessing one and the same character as the nourishment of which it is the residue, it is probable that the stuff produced by the " honeycombers " is similar to the substance out of which they were originally constituted ; hence it is reasonable to suppose that it too " gives rise to young ones.

All which neither produce sideshoots nor make (6) Spon" honeycombs " reproduce by spontaneous genera- '^nerafjon tion ; and all which arise in this manner whether on land or in the water come to be formed, as can be seen, to the accompaniment of putrefaction and admixture of rainwater : as the sweet ingredients are separated off into the principle which is taking form, that which remains over assumes a putrefying aspect."* Nothing, however, is formed by a process of putrefaction, but by a process of concoction : the putrefaction

  • i.e., as well as residues such as semen. ** i.e., putrefies,

and the putrefied matter are a residue of that which has been concocted, for no creature's formation uses up the trhole of the material," any more than in the case of objects fashioned by the agency of art, otherwise there would be no need to make anything at all, whereas what happens in actual fact is that the useless material is removed in the one case by art and in the other by Nature.

Animals and plants are formed in the earth and in the water because in earth water is present, and in water pneuma is present, and in all pneuma soul-heat is present,* so that in a way all things are full of Soul ; and that is why they quickly take shape once it has been enclosed. Now it gets enclosed as the liquids containing corporeal matter '^ become heated, and there is formed as it were a frothy bubble. The object which thus takes shape may be more valuable in kind or less valuable ; and the differences herein depend upon the envelope which encloses the soulprinciple ; and the causes which determine this are the situations where the process takes place and the physical substance which is enclosed. Now in the sea earthy substance is plentiful, and that is why the Testacea "^ are formed and constructed out of a composition which is earthy in character : the earthy substance hardens all round and congeals in the same way that bones and horns do (since these cannot be melted by fire), while within it the physical substance that contains the life becomes enclosed.

Of such creatures the only tribe which has been observed to copulate is that of the snails ; but whether ' Sea-water is such a liquid ; see above, 761 b 9 and immediately below, 1. 27. Also App. B §§ 13-17.

or not their generation is the result of such copulation has not so far been adequately observed.

Anyone who wishes to follow the right line of in- Theory of quiry might well inquire what it is which, as it takes deration!' shape, corresponds in the case of these creatures to the " material principle." In females of course this is a residue produced bv the animal, a residue which potentially is such as the parent is from which it came, and which is perfected into an animal by the principle from the male " imparting movement to it. In the present case, however, what are we to describe as holding this sort of position ? and whence comes the principle that imparts movement , corresponding to the male, and what is it ? Now we must apprehend that, even in the case of those animals which generate, it is the incoming nourishment that is the material out of which the heat residing in the animal produces the residue - the " principle " of the fetation - by setting it apart and concocting it. Similarly ^^•ith plants, except that with them and certain of the animals there Ls no need of the principle of the male over and above that, because they contain in themselves this principle mixed (with the female) ; in most animals, however, the residue does need this principle. Of the one set, the nourishment is water and earth ; of the other, it is the things that are formed out of these ; so that in their case the seasonal heat present in their en\ironment causes to accumulate and to take shape by means of concoction out of sea-water and earth that which in the case of animals the heat present in them produces out of the nourishment. And that portion of the soul-principle which gets enclosed or separated oflF within the pneuma makes a fetation and implants movement in it. Now as for plants, the manner in which those plants take shape which are generated spontaneously is uniform : they are formed from a part " of something, and some of it forms into the " principle," some into the first nourishment of the germinating plants. As for the animals, however, some of them are brought forth as larvae, both the bloodless ones that are not formed from li^ing animals, and some blooded ones (examples are a kind of cestreus ^ and other river fishes, also the eel tribe) : all of these, although by nature they have but little blood, nevertheless are blooded animals and have a heart, which is the " principle " of the parts and bloodlike in constitution. The " earth 's-guts " as they are called have the nature of a larva ; the body of the eels forms within them.'^ Hence, too, with regard to the genera- Tr.-idiiionai tion of human beings and quadrupeds, if once upon ori^n*^of^* a time they were " earthborn " as some allege, one man and might assume them to be formed in one of these two *°""* '• ways - ^either it would be by a larva taking shape to begin with, or else they were formed out of eggs, since of necessity they must either contain the nourishment for their growth within themselves (and a fetation of this sort is a larva) or they must get it from elsewhere, and that means either from the female parent " or from part of the fetation ^ ; so that if the former way is impossible (i.e., if it cannot flow to them out of the earth as it flows to animals from the mother), of necessity they must get it from part of the fetation, and generation of this sort we call generation from an egg. Thus much, therefore, is plain : if there were a " principle " of their generation in the case of all animals, we should reasonably expect it to be one or other of these two, larva or egg. It is, however, less reasonable to hold that their generation would take place out of eggs, because in the case of no animal do we observe this sort of generation '^ to occur, whereas we do see the other, in the case both of the blooded animals I mentioned •* and the bloodless ones. Under this latter heading come certain of the Insects, and also the Testacea with which our discussion is concerned : they are not formed out of a part of something as are the creatures produced from eggs, and further, they effect their growth in a similar way to larvae, for larvae grow towards the upper part, towards the " principle," the nourishment for the upper parts being in the lower part. In this respect they resemble the creatures that are produced from eggs, except that the latter use up the n-hole of the egg, whereas, in the case of those produced from larvae, when the upper part has grown by drawing on the substance in the lower part, then the lower part becomes articulated out of what remains. The reason for this is that (not only in the early stages but) afterwards as well * the nourishment is produced in the part below the diaphragm in all animals. That the larva-like creatures effect their growth in this manner is plain in the case of bees and insects of that sort, as their lower part is large to start with and the upper part smaller. The arrangements for growth in the Testacea are on the same lines. This is shown in the convolutions of the spiral-shelled creatures, which as thev grow always become larger towards the front and the " head " as it is called.

This practically completes our description of the manner of generation of these animals and of the others that are generated spontaneously.

The fact that all " the Testacea take shape spon- Examples of taneously is shown by considerations like the follow- spontaneous ing : They form on the side of boats when the frothy ° slime * putrefies ; and also, in many places where nothing of the kind had been present pre\'iously, after a time when the place has become muddy owing to lack of water, "^ lagoon-oysters, as they are called, a kind of testaceous animal, have been formed ; for example, on an occasion when a naval squadron cast anchor off Rhodes, some earthenware pots were thrown out into the sea, and as time went on and mud had collected round them, oysters were continually found inside them. Here is a piece of evidence to show that animals of this kind emit no generative substance : people from Chios transported some live oysters across from Pyrrha in Lesbos,'

    • Cf. H.A. 547 b 11. Apparently barnacles, which are, however, Crustacea, not Testacea.

and deposited them in some sea-straits where the currents met." As time passed the oysters did not increase at all in number, but they grew greatly in size. As for their " eggs," * as they are called, these contribute nothing to generation ; they are just a sign of good nourishment, like fat in blooded animals, and that too is why they are tasty to eat at these seasons. A proof of this is that these creatures - e.g., pinnae, whelks and purpurae - have such " eggs " as these always, only sometimes they are larger, sometimes smaller. Others - e.g.. pectens, mussels and the lagoon-oysters as they are called - do not have them always, but only in the spring ; as the season advances they wane, and finally disappear altogether ; the reason being that the spring-season is favourable to their physical condition. In others - e.g., the seasquirts - nothing of the kind is to be detected. For an account dealing with these indi%"idually, and the places where they grow, the student should consult the Researches.

verb p€(t} elsewhere in connexion with evpinos, e.g. E.N. 1167 b 7 ^e'vet rd ^vXevfiara kcu ov fierappei utcrnep evpiiros: cf. Prob. 940 b 16 oi evpirroi, peovaiv, and De somno et vig. 456 b 2\. Gaza's translation luto similia seems to imply the reading ^opfiopmheis, which is entirely against the sense. ' See note on 763 b 1.


The dotted lines represent mesoblast. The diagram shows the state of development after about ten days. The embryo itself is in the central part of the diagram. Immediately above the gut is the notochord (shown in black), and immediately above that is the nerve-cord, of which the right end is the brain. The two " umbilical cords " mentioned by Aristotle (III. 753 b 20 £f.) are shown : (a) the yolk-sac stalk, (b) the stalk of the allantois.

To begin with, the embryo is a sort of thin plate on top of the yolk ; and as time goes on, both the amniotic cavity (which encloses the embryo) and the allantois (which acts as a respiratory organ and as a receptacle for excreta) progressively encircle the yolk, which finally becomes enclosed in the embryo (as Aristotle says). The chorion and allantois coalesce after a period, and the resulting chorio-allantois then corresponds to the fetal placenta of mammals. The chorion is really the outer layer of the amnion. The extra-embryonic coelom, wliich is lined with, is an extension of the coelom proper (the main body-cavity), which is also lined with mesoblast.

Book IV

The formation of animals, both in general and as con- I cems all of them separately, has now been dealt vrith. ^^n-"'. Since, however, in the most perfect " of them the entiation. male and the female are separate, and we hold that theories: these characteristics ^ are " principles " "^ of all animals and all plants ahke (the only difference being that in some these " principles " are inseparable while in others they are separate), we must deal with the formation of these first of all, for male and female become distinct while animals are still imperfect in kind.*^ It is however not agreed whether one is male and another female even before the difference is plain to our senses, the difference being acquired by them either within the mother or earlier. Thus, Anaxagoras. some people, such as Anaxagoras and certain other physiologers, say that this opposition exists right back in the semens,^ alleging that the semen comes Aristotle's view will be found in the passage below, 766 a 30b 3. The heart is the first thing to be formed in the embryo, because it is the seat of to dpeirriKov, the nutritive part of the Soul; and to BpermKov is also ro yewrjriKov (see 735 a 17 fF., 744 b 36, n.). Sex can be ultimately traced back to the heart, which, as also containing the principle of vital heat, is the source of concoction, upon which ability to produce semen, etc., depends.

int# being from the male, while the female provides the space for it," and that the male comes from the right side * and the female from the left [and, as regards the uterus, that the males are in the right side and the female in the left]'^. Others, like Empedocies Empedocles, hold that the opposition begins in the D^mocritus. womb ; according to him, the semens which enter a hot womb become males, those which enter a cold one, females ** ; and that the cause of this heat and cold is the menstrual flow, according as it is hotter or colder, older or more recent/ Democritus of Abdera holds that the difference of male and female is produced in the womb, certainly, but denies that it is on account of heat and cold that one becomes male and another female ; this is determined, he asserts, according to which of the two parents' semen prevails, the semen, that is to say, which has corne from the part wherein male and female differ from one another/ After all, Empedocles was really rather slipshod in his assumption, in supposing that the two differ from each other merely in virtue of heat and cold, when he could see that the whole of the parts concerned - the male pudenda and the uterus - exhibit a great difference^ for supposing that once the animals have been fashioned, and one has got all the parts of the male and the other all the parts of the female, they were to be put into the uterus as though it were into an oven, the one which has a uterus into a hot oven, and the one which has no uterus into a cold one, then it follows that the one that has no uterus will turn out a female and the one that has a uterus a male. And this is impossible. So that we may allow that in this respect Democritus's statement is the better of the two, because he is trying to find out what is the difference inherent in this process of formation of male and female, and endeavouring to state it, though whether he is right or not is another matter. Yet indeed, if heat and cold were the cause of the difference of the actual parts," then those who hold the other \-iew * ought to have stated this, because, one might say, this is tantamount to making a statement about the process of formation of male and female, since it is in these parts that the evident difference between the two lies. And also, if you start from this principle,"^ you have your work cut out to prove the cause of the process of formation of these parts, and to show that it necessarily follows that when the animal is cooled the part called the uterus is formed in it, but that when it is heated it is not formed. The same may be said about the parts which serve for intercourse, since these too differ, as has already been stated.

Further, male and female twins are often formed together in the same part of the uterus. This has and cold (see above, 1. 13), and that this had little or nothing to do with the difference of the sexual organs. But it seemsimpossible that Empedocles could have meant anything else than that heat and cold were the cause of the difference of the sexes, including that of the distinctive organs. ' i.e., of heat and cold.

been amply observed by us from dissections in all the Vivipara, both in the land-animals and in the fishes. Now if Empedocles had not detected this, it is understandable that he should have made the mistake of assigning the cause he did ; if on the other hand he had detected it, it is extraordinary' that he should still continue to think that the cause is the heat and cold of the uterus, since according to his theorv the twins should both turn out male, or both female ; whereas in actual fact we do not observe this to occur.

Also, he says that the parts of the creature which gets formed are " torn asunder " " ; some, he savs, are in the male and some in the female, and that also explains why they desire intercourse with each other. If so, necessity requires that the physical substance ^ of these parts as well as of the others is " torn asunder " and that a junction takes place, not that the difference is due to coohng or heating. However, discussion of a cause of this sort might well prove lengthy, as the whole cast of this cause seems to be a product of the imagination. If on the other hand the truth about semen is as we have actually stated - i.e., that it is not drawn from the whole body and that the secretion from the male provides no material at all for the creatures which get formed^ - then we must take up our stand against Empedocles and against Democritus and against anyone else who maintains this position, because (a) it is impossible below. fieyeBos thus means something which has size, i.e., a physical body or substance. Empedocles, says Aristotle, is inconsistent in saying (a) that the physical substance of the parts is present as such in the parents to begin with, and (6) that the formation of the sexual parts is due to the action of heat and cold.

that the physical substance " of the semen ^ exists " torn asunder," one part in the male and the other in the female, as Empedocles alleges- But torn asunder waits The substance of the limbs ; part is in man's ..." and (6) it is impossible that a complete tale •* of parts is secreted off from each of the parents and that a male or female embryo is formed according as one part prevails over another part/ Considering the matter generally : To hold that the superiority of one part prevails and that this is what makes the embryo female is certainly better than saying that heat alone is the cause \^'ithout having stopped to think about it ; but the fact that at the same time the conformation of the pudendum as well ^ is different requires an explanation to show why these parts are always of a piece with each other.^ If the answer is " Because they are in close proximity," then every one of the remaining parts ought to be all of a piece as well,'* since while the parts are gaining the mastery * any one of them is close to any other, so that on that showing all the characteristics should go together, i.e., the offspring, if female, should also take after its mother, and if male after its father.^ Besides, it is fantastic to imagine that these parts alone can be formed, without the whole body also having under

gone a change,* and first and foremost the bloodvessels, on to which the fleshy structure of the body has been applied all round, as on to a framework.* And it is reasonable to suppose not that the bloodvessels have been formed to be of a particular character on account of the uterus, but rather that the uterus has been so formed on account of them, since although each is a receptacle of blood in some form, the blood-vessels are prior to the uterus ; and the motive principle must of necessity be prior always and be the cause of the process of formation in \irtue of possessing a particular character.*^ So then, this difference of the sexual parts as between males and females is a contingent phenomenon ** : we must not look upon it as being a " principle " or a cause : this function is fulfilled by something else, even though no semen at all is discharged either by the female or by the male and whatever the manner may really be by which the forming creature takes shape.

The same argument which we used against Empedocles and Democritus holds good against those who allege that the male comes from the right side and the female from the left * : thus if the male contributes no material at all, then those who take this \-iew are of course talking nonsense ; if on the other hand it does contribute something, as they assert, we have to counter them in the same way that we countered Empedocles' argument which draws the line as between male and female by reference to the heat and coldness of the uterus. They make the same mistake as he does, ih drawing the line by is an " accidental," not an " essential," characteristic. For the sentiment, see 766 b 3 ff .

reference to right and left, although they can see for themselves that male and female differ in fact by the entirety of the parts concerned. By what cause, then, will the uterus " be present in those which come from the left side but not in those which come from the right ? Supposing dne comes (from the left) ^vithout having got this part, there ^vill be a female without a uterus - or if it so chance, a male with one ! [Again, as has in fact been said before, a female embryo has actually been observed in the right part of the uterus, and a male one in the left part, and both male and female in the self-same part, and that not once but several times over ; or the male one on the right side, and the female on the left, and no less both are formed on the right side].** There are some who are firmlv con\-inced of a similar view to this, and maintain that males who copulate with the right or left testicle tied up produce male or female offspring respectively : this used in fact to be maintained by Leophanes."^ Some allege that the same occurs in the case of those who have one testis excised. This statement is untrue, and is a mere piece of guesswork on their part. They start from probabihties and guess what will occur ; they prejudge that it is so before they see it happen. Added to which they do not know that these parts of animals contribute nothing at all to generation so far as producing male and female offspring is concerned ; and a proof that this is so is that many animals, although thev are themselves male and female and generate male and female offspring, 4. 11 ; and the fact that in Aetius' Placita V. 7. 5 {Doxogr. 420 a 7) he comes between Anaxagoras and Leucippus may give a rough indication of his date.

possess no testes - as is the case with the animals that have no feet, e.g., the tribes of fishes and serpents." Now the opinion that the cause of male and female is heat and cold, and that the difference depends upon whether the secretion comes from the right side or from the left, has a modicum of reason in it, because the right side of the body is hotter than the left ^ ; hotter semen is semen which has been concocted ; the fact that it has been concocted means that it has been set and compacted,*^ and the more compacted semen is, the more fertile it is.** x\ll the same, to state the matter in this way is attempting to lay hold of the cause from too great a distance, and we ought to come as closely to grips as we possibly can \\"ith the primary causes.* • We have dealt already elsewhere ^ with the body as The ftmdaa whole and with its several parts, and have stated â„¢i3°^etion what each one is, and on account of what cause it is betweon so. But that is not all, for (1) the male and the "^4"^ female are distinguished by a certain ability and inability.* Male is that which is able to concoct, to cause to take shape, and to discharge, semen ' possessing the " principle " of the " form " ; and by " principle " I do not mean that sort of principle out of which, as out of matter, an offspring is formed belonging to the same kind as its parent, but I mean the Jirst motive principle, whether it is able to act thus ' in itself or in something else. Female is that which receives the semen, but is unable to cause semen to take shape or to discharge it. And (2) all I Ducoction works by means of heat. Assuming the truth of these two statements, it follows of necessity that (3) male animals are hotter than female ones, since it is on account of coldness and inability that the female is more abundant in blood in certain regions of the body. And this abundance of blood is a piece of evidence which goes to prove the opposite of the vievr held by some people, who suppose that the female must be hotter than the male, on account of the discharge of menstrual fluid : blood, they argue, is hot, so that which has more blood in it Is hotter. They suppose, however, that this condition occurs owing to excess of blood and heat, as though it were possible for anything and everything to be equally blood if only it is fluid and bloodhke in colour, without allowing for the possibiUty of its becoming less in quantity and purer in animals that are wellnourished. They apply the same standard here as they do to the residue in the intestine : if there is more of it they imagine that is a sign of a hotter nature. Yet in fact the opposite is the truth. Take a parallel case, that of fruit. Here the nourishment in its first stage is large in quantity," but the useful product resulting from it through the various stages of its treatment is small, and in the end the final result is nothing in proportion compared -with the original bulk. So too in the body, the various parts receive the nourishment in turn at the different stages of its treatment, and the final product resulting from all that amount of nourishment is quite small. In some, this is blood ; in others, its counterpart.

to secrete the residue in a pure condition ; and as in the there is an instrument for every abiUty or faculty, for ®™ '^°" the one which yields its product in a more finisheck condition and for the one which yields the same product in a less finished condition ; and as male and female stand opposed in this way (" able " and " unil)le " being used in more senses than one ^) ; there•re of necessity there must be an instrument * both for the male and for the female ; hence the male has the perineos '^ and the female has the uterus. Nature gives each one its instrument simultaneously with its ability, since it is better done thus. Hence each of these regions of the body gets formed simultaneously with the corresponding secretions and abilities, just as the abihty to see does not get perfected without eyes, nor the eye without the abiUty to see, and just as the gut and the bladder are perfected simultaneously ^\•ith the ability to form the residues. Now as the stuff out of which the parts are formed is the same as that from which they derive their growth,*^ namely the nourishment, we should expect each of the parts to be formed out of that sort of material and that sort of residue which it is fitted to receive. Secondly, and on the contrary, it is, as we hold, formed in a way out of its opposite. Thirdly, in addition, it must be laid down that, assuming the extinction of a thing means its passing into its opposite condition, then also that which does not get mastered by the agent which is fashioning it must of necessity change over into its opposite condition.* With these ^ For this distinction between the grades of nourishment, see 744 b 32 if.

as our premisses it may perhaps be clearer why and by what cause one offspring becomes male and another female. It is this. When the " principle " " is failing to gain the mastery and is unable to effect concoction OA\ing to deficiency of heat, and does not succeed in reducing the material into its own proper form,^ but instead is worsted in the attempt, then of necessity the material must change over into its opposite condition.'^ Now the opposite of the male is the female, and it is opposite in respect of that whereby one is male and the other female.** And since it differs in the abiUty it possesses, so also it differs in the instrument which it possesses. Hence this is the condition * into which the material changes over. And when one \'ital part changes,^ the whole make-up of the animal differs greatly in appearance and form. This may be observed in the case of eunuchs ; the mutilation of just one part of them results in such a great alteration of their old semblance, and in close approximation to the appearance of the female. The reason for this is that some of the body's parts' are " principles," and once a principle has been " moved " [i.e., changed), many of the parts which cohere ^ with it must of necessity change as well.

Let us assume then (1) that " the male "is a The principle and is causal in its nature ; (2) that a male ^u^'^^f s male in \irtue of a particular abiUty, and a female "ex u the female in virtue of a particular inabiUty ; (3) that the ** ine of determination between the ability and the nability is whether a thing effects or does not effect hat the sexual parts, as distinct from the sexes, are " prin•iples " ; but his position is made clear by the passage 66 b 2 flF.

concoction of the ultimate nourishment (in blooded animals this is known as blood, in the bloodless ones it is the counterpart of blood) ; (4) that the reason for this hes in the " principle," i.e., in the part of the body Avhich possesses the principle of the natural heat. From this it follows of necessity that, in the blooded animals, a heart must take shape and that the creature formed is to be either male or female, and, in the other kinds " which have male and female sexes, the counterpart of the heart. As far, then, as the principle and the cause of male and female is concerned, this is what it is and where it is situated ; a creature, however, really is male or female only from the time when it has got the parts by which female differs from male, because it is not in \-irtue of some casual part that it is male or female, any more than it is in virtue of some casual part that it can see or hear.* To resume then ^ : We repeat that semen has been Consequent posited to be the ultimate residue of the nourish- fo^^'a\^on^° ment. (By " ultimate " I mean that which gets car- of sexual ried to each part of the body - and that too is why ^'^* the offspring begotten takes after the parent which has begotten it, since it comes to exactly the same thing whether we speak of being drawn from every one of the parts or passing into every one of the parts, though the latter is more correct.**) The semen of the male, however, exhibits a difference,

  • The following paragraph is a short recapitulation, with additions, of the main points of the preceding argument, 765 b 8 - 766 b 7. (For the use of imoKinai with jjarticiple, c/. 778 b 17 ~oi.6vh€ t,iuov vnoKfiTcu 6v.)

"* See Bk. I. 721 b 13 ff., and especially the conclusion of that discussion, 725 a i?l if.

inasmuch as the male possesses in itself a principle of such a kind °' as to set up movement [in the animal as well] and thoroughly to concoct the ultimate nourishment, whereas the female's semen contains material only. If (the male semen) gains ^ the mastery, it brings (the material) over to itself; but if it gets mastered, it changes over either into its opposite or else into extinction. And the opposite of the male is the female, which is female in \irtue of its inability to effect concoction, and of the coldness of its bloodUke nourishment. And Nature assigns to each of the residues the part which is fitted to receive it. Now the semen is a residue, and in the hotter of the blooded animals, i.e., the males, this is manageable in size and amount,*^ and therefore in males the parts which receive this residual product are passages ; in females, however, on account of their failure to effect concoction, this residue is a considerable volume of bloodlike substance, because it has not been matured ; hence there must of necessity be here too some part fitted to receive it, different from that in the male, and of a fair size. That is why the uterus has these characteristics ; and that is the part wherein the female differs from the male.** We have now stated the cause why some creatures are formed as males, others as females.

And our statements are borne out by the facts. II Thus : Young parents, and those which are older too, â– ^^® ^^^f^.

which are in their prime ; the reason being that in the young their heat is not yet perfected, in the older, it is faihng. Also, parents which are more fluid of body and feminine tend to produce females : this is true also of fluid semen as opposed to that which has " set " : all these things are due to a deficiency of natural heat.

Also, the fact that when the wind is in the north " male offspring tend to be engendered rather than when it is in the south (is due to the same cause : animals' bodies are more fluid ^ when the wind is in the south) so that they are more abundant in residue as well. And the more residue there is, the more difficulty they have in concocting it ; hence the semen of the males and the menstrual discharge of the women is more fluid.

Also, the fact that the menstrual discharge in the natural course tends to take place when the moon is waning '^ is due to the same cause. That time of month is colder and more fluid on account of the waning and failure of the moon (since the- moon makes a summer and \\inter in the course of a month just as the sun does in the course of the whole year. [This is not due to its turning at the tropics ; no, the one occurs when the moon's light is increasing, the other when it is waning.'*]). Also, shepherds say that it makes a difference so far as the generation of males and females is concerned not only whether copulation occurs when the wind is in the north or in the south, but also whether that whereas summer and winter result from the " turnings " of the sun, viz., the solstices, the " summer " and " winter " of the moon are not due to the moon's " turnings," but to its waxings and wanings, which are completely independent of its " turnings."

the animals face north or south while they are copulating <* : such a small thing thrown in on one side or the other (so they say) acts as the cause of heat and cold, and these in turn act as the cause of generation.

Male and female, then, differ generally with regard importance to each other in respect of the generation of male and ^^^e-pia. female offspring on account of the causes which have been stated. At the same time, they must stand in a right proportional relationship to one another,^ since everj^thing that is formed either by art or by nature exists in virtue of some due proportion. Now if " the hot " is too powerful it dries up fluid things ; if it is very deficient it fails to make them " set " ; what it must have in relation to the object which is being fashioned, is the mean proportional, and unless it has that, the case will be the same as what happens when you are cooking : if there is too much fire it burns up your meat, if there is too little it \\ill not cook it - either way what you are trying to produce fails to reach completion. The same applies to the mixture of the male and the female : they require the right proportional relationship, and that is the reason why it happens that many couples fail to effect generation with one another, but if they change partners they succeed ; and also that these oppositions occur sometimes in young people, sometimes among those who are older, both with regard to failure and success in generation and also vriih regard to the generation of male and female offspring. •^ Also, one country differs from another in these Effect of respects, and one water from another, on account of '^^""^*^^the same causes, for the quality of the nourishment especially and of the bodily condition of a person

depends upon the blend " of the surrounding air and of the foods which the body takes up, and especially upon the nourishment supplied by the water, since this is what we take most of, water being present as nourishment in everything, even in solid substances as well. Hence hard, cold water in some cases causes barrenness, in others the birth of females.* The following things are due to these same causes. Ill Some offspring take after their parents and some ^„"â„¢\o do not ; some after their father, some after their parents and mother, as well in respect of the body as a whole as '^°" *'"^' in respect of each of the parts, and they take after their parents more than after their earlier ancestors, and after their ancestors more than after any casual persons. Males take after their father more than their mother, females after their mothor. Some take after none of their kindred, although they take after some human being at any rate ; others do not take after a human being at all in their appearance, but have gone so far that they resemble a monstrosity, and, for the matter of that, anyone who does not take after his parents is really in a way a monstrosity, since in these cases Nature has in a way strayed from the generic type. The first beginning of this deviation is when a female is formed instead of a male, though (a) this indeed is a necessity required by Nature,^ since the race of creatures which are separated into male and female has got to be kept in being '^ ; and (b) since it is possible for the male sometimes not to gain the mastery either on account of youth or age or some other such cause, female produced in the normal course of nature {aianep dvaTrrjpiav <})vaiicriv). See Introd. § 13.

Offrspring must of necessity be produced by animals." As for monstrosities, they are not necessary so far as the purposive or final cause is concerned, yet per accidens they are necessary, since we must take it that their origin at any rate is located here. Thus : If the seminal residue in the menstrual fluid is wellconcocted, the movement derived from tlie male will make the shape after its own pattern.^ (It comes to the same thing whether we say " the semen " or " the movement which makes each of the parts grow " ; or whether we say " makes them grow " or " constitutes and ' sets ' them from the beginning " - because the logos of the movement is the same either way.) So that if this movement gains the mastery it v,-il\ make a male and not a female, and a male which takes after its father, not after its mother ; if however it fails to gain the mastery, whatever be the " faculty " in respect of which it has not gained the mastery, in that " faculty " it makes the offspring deficient. " Faculty," as appUed to each instance, I use in the following sense. The generative parent is not merely male, but in addition a male with certain characteristics, e.g., Coriscus or Socrates ; and it is not merely Coriscus, but in addition a human being. And it is of course in this sense that, of the characteristics belonging to the generating parent, some are more closely, some more remotely his, qua procreator (not qua anything else he may be per accidens, e.g., supposing he were a good scholar or somebody's next-door neighbour) ; and where generation is concerned, it is always the peculiar and indi\idual characteristic that exerts the stronger influence. Thus : Coriscus is both a human being and an animal ; but the

formec characteristic stands closer to what is peculiar to him than the latter does. Now both the individual and the genus to which it belongs are at work in the act of generation ; but of the two the indi\"idual takes the leading part, because this is the really existent thing " ; the offspring also which is formed, though of course it is formed so as to possess the generic characteristics, at the same time comes to be a particular indi\idual - and this, again, is the really existent thing. Therefore, it is from the " faculties " of all such things as these * that the movements which are present in the semens are derived, potentially even from <the faculties) of earlier ancestors, but more specially of that which on each occasion stands closer to some individual ; and by individual I mean Coriscus, or Socrates. Now everything, when it departs from type.*' passes not into any casual thing but into its OAvn opposite ; thus, applying this to the process of generation, the (substance) which does not get mastered must of necessity depart from type and become the opposite ** in respect of that " faculty " wherein the generative and motive agent has failed to gain the mastery. Hence, if this is the " faculty " in Wrtue of which the agent is male, then the offspring formed is female ; if it is that in virtue of which the agent is Coriscus or Socrates, then the offspring formed does not take after its father but after its mother, since, just as " mother " is the opposite of " father " as a general term, so also the individual mother is the opposite of the indixidual father. The same applies to the " faculties " that stand next in order, since the offspring always tends to shift over to that one of its ancestors which stands next, both on the father's side

and the mother's. Some of the movements (those of the male parent and those of general kinds, e.g., of human being and animal) are present in (the semen) in actuality, others (those of the female and those of ancestors) are present potentially. * Now when (a) it ^ departs from type,*^ it changes over into its opposites; but when (6) the movements which are fashioning the embryo relapse, they relapse into those which stand quite near them ; for example, if the movement of the male parent relapses, it shifts over to that of his father - a very small difference- and in the second instance to that of his grandfather. And in this way too [not only on the male side but also on the female] the movement of the female parent shifts over to that of her mother, and if not to that, then to that of her grandmother ; and so on with the more remote ancestors.

(1) Usually the natural course of events is that when (the movement of the male parent) ** gains the mastery - and when it is mastered - it will do so both qua male and qua individual father,* since the difference between the two (faculties) is a small one, and so there is no difficulty in their both coinciding (for Socrates is a man who, while (a) he has the characteristics of a class,^ (6) is also an individual). Hence for the most part males take after their father - and females after their mother, since a departure from type takes place in both directions "

simultaneously, and the opposite of " male " is "female" and the opposite of "father" is "mother," departure from type always being into f»pposites." But (2) if the movement that comes from " the male " gains the mastery and the movement that comes from Socrates does not, or the other way round, then the result is that male offspring taking after their mother are formed and female ones taking after their father. Supposing (S) the movements relapse : if (i) the male " faculty " stands fast but the movement from Socrates ^ relapses into that of his father, then the offspring will be male and take after its grandfather or some other more remote ancestor [according to this principle] ; if (ii) the male-faculty gets mastered, the offspring will be female, and usually will take after the mother ; but supposing this movement also relapses, it will take after the mother's mother or some other more remote ancestor on the same principle. Precisely the same scheme holds good with the various parts of the body ; very often, of course, some parts take after the father and some after the mother, and others after some of the ancestbrs, since the movements belonging to the parts '^ as well are present in (the seminal substance), some of them in actuality, some potentially, as has often been stated. We Absence of must lay down as general principles that which we r*â„¢*^stated just now, for one (viz., that some of the biance. movements are present in <the seminal substance) potentially, others in actuality), and also two others : (a) that which gets mastered departs from type and passes into its opposite ; (6) that, however, which relapses passes into the movement next to it in order : if it relapses a httle, into the movement

which is close by, if more, into that which is further removed. In the end, they become so confused that the product does not take after any of its family or kindred, and all that remains is what is common to the race^ - i.e., it is just a human being. The reason for which is that all particular individuals are accompanied " by this characteristic : since " human being " is general, whereas Socrates who is the father, and the mother whoever she may be, are to be classed as particular individuals.

(1) The reason why the movements relapse is that The the agent in its turn gets acted upon by that upon ^{'^^^^gai which it acts (e.g., a thing which cuts gets blunted and by the thing which is cut, and a thing which heats '^"" gets cooled by the thing which is heated, and, generally, any motive agent, except the " prime mover," gets moved somehow itself in return, e.g., that which pushes gets pushed somehow in return, and that which squeezes gets squeezed in return ; sometimes the extent to which it gets acted upon is greater than that to which it is acting - a thing which heats may get cooled, or one which cools may get heated, sometimes (a) without having acted at all, sometimes (6) ha\'ing acted less than it has been acted upon. These matters have been discussed in the treatise on Acting and being acted upoii,'^ where it is stated in what sorts of things acting and being acted upon occur). (2) The reason, however, why that which is acted upon departs from type and does not get mastered is either (a) deficient potency in the concocting and motive agent, or (h) the bulk and coldness of that which is being concocted and articulated ; since (the motive agent), gaining the mastery at one Uneven place but not at another, causes the embryo that is mlnt^

taking shape to turn out diversiform. This is just what happens to athletes through eating an excessive amount ; in their case, owing to the great bulk of nourishment there is, Nature cannot gain the mastery over it so as to bring about well-proportioned growth and distribute the nourishment evenh" throughout ; the result is that the parts turn out ill-assorted, and sometimes even bear hardly any resemblance at all to what they were like before. Similar to this is the disease which is known as satyriasis : [in this too, a large bulk of unconcocted flux or pneuma finds its way into parts of the face of the animal, and in consequence the face actually appears like that of a satyr.] ° We have now expounded the cause of all the following : whv male and female offspring are formed ; why some take after their parents, female after female and male after male, and others the other way round, females taking after their father and males after their mother ; and generally why some take after their ancestors and some after none of them, in respect both of the body as a whole and of each of its parts.

Certain of the physiologers, however, have treated Earlier of these matters on different lines, explaining other- of^"em. wise the cause why offspring are formed similar and biance dissimilar to their parents. The cause is presented by them in two ways. (1) Some say that the offspring which is formed takes more closely after that " This sentence is probably a marginal note which has crept into the text ; in any case it is corrupt, and " unconcocted pneuma " is meaningless. Scot has no mention of animal or face ; see critical note. The disease seems to be elephantiasis.- With b 30-37 however cf. Pol. 1302 b 35 ff.

parent from which the larger portion of the semen comes, and that the whole of the offspring takes after the whole of the parent, and part after part (this assumes that semen is drawn from each of the parts) ; if the same amount comes from each of the two, then, they say, the offspring formed resembles neither. But if this is untrue (as it is), i.e., if the semen is not drawn from the whole of the body, then, clearly, the reason they give for the similarity and dissimilarity of the offspring cannot be true either. Further, they cannot explain with any ease how it is that at the same time a female offspring takes after the father and a male offspring after the mother ; for those who state the cause of male and female as Empedocles or Democritus state it," make statements which on another score are impossible ; while those who maintain that it all depends upon whether more or less semen comes from either the male or the female, and that this is why one offspring is formed as a male, and another as a female, these people, I am sure, are not in a position to show how the female is going to take after the father and the male after the mother, since it is impossible for more semen to come from both parents at one and the same time. And further, for what cause is it that the offspring for the most part takes after its ancestors, even distant ones ? Surely no portion at ail of the semen has come from them, anyway. (2) One more type of explanation of the resemblance remains to be mentioned, and those who adopt it make a better show all round, including this particular question. There are some who hold that the semen, though a unity, is as it were a " seedaggregate " consisting of a large number of ingredients ; it is as though someone were to mix and

blend together a large number of juices into one fluid, and then take off some of this mixture ; in doing so he could take off not always an equal amount of each • juice, but sometimes more of this one, sometinaes more of that, and sometimes he might take some of one and nothing at all of another : So, they say, it is with the semen, which is a mixture of a large number of ingredients ; and in appearance the offspring takes after that parent from whom the largest amount is derived. This theory is obscure, and at many points a sheer fabrication. At the same time, it aims at a more satisfactory " statement, viz., that this " seedaggregate " is something that exists not in actuality. but only potentially, since it cannot exist in actuality, whereas it can exist potentially.

Still it is not easy, by stating a single mode of cause, to explain the causes of everything, - (1) why male and female are formed, (2) why female offspring often resembles the father and male offspring the mother, and again (3) the resemblance borne to ancestors, and further (4) what is the cause why sometimes the offspring is a human being yet bears no resemblance to any ancestor, sometimes it has reached such a point that in the end it no longer has the appearance of a human being at all, but that of an animal only - it belongs to the class of monstrosities, as they are called.

And indeed this is what comes next to be treated Monstrosi. after what we have already dealt with - the causes of ^^' monstrosities, for in the end, when the movements (that came from the male) relapse and the material (that came from the female) does not get mastered, what remains is that which is most " general," and this is the (merely) " animal." People say that the

offspring which is formed has the head of a ram or an ox ; and similarly with other creatures, that one has the head of another, e.g., a calf has a child's head or a sheep an ox's head. The occurrence of all these things is due to the causes I have named ; at the same time, in no case are they what they are alleged to be, but resemblances only, and this of course comes about even when there is no deformation involved. Thus, humorists often compare those whose strong point is not good looks in some cases with a firespouting-goat, in others with a butting ram ; and there was a physiognomist who in his lectures used to show how all people's faces could be reduced to those of two or three animals, and very often he carried con\iction with his audience. It is however impossible for a monstrosity of this type to be formed (i.e., one animal within another), as is shown by the gestation-periods of man, sheep, dog, and ox, which are widely different, and none of these animals can possibly be formed except in its own proper period.

This, then, is one sort of " monstrosity " we hear spoken of. There are others which qualify for the name in virtue of having additional parts to their body, being formed ^\ith extra feet or extra heads.

The account of the cause of monstrosities is very close and in a way similar to that of the cause of deformed animals, since a monstrosity is really a sort of deformity.

Now Democritus " explained the formation of IV monstrosities thus. Two semens fall into the uterus, dancy oi one of them having started forth earlier and the other parts. later, fand the second when it has gone out goes "

into the uterus,t " with the result that the parts grow on to one another and get thrown into disorder. [In the case of birds, since copulation is a quick business with them always, the eggs and their colour as well, he says, get thrown into disorder.]^ But if it is a fact that several offspring are formed from one semen and from one act of copulation, as is evidently the case, we should do better not to neglect the shortest route and go a long way round, since in cases of this sort it is absolutely necessary that this should happen when the semens have not been separated but proceed together.*^ Now if we are really obliged to refer the cause to the semen that comes from the male, then, I suppose these are the hnes on which we should make our explanation ; but from every point of view we ought preferably to hold that the seat of the cause is the material ** and in the fetations as they take shape. And that too explains why monstrosities of this sort, while they occur very seldom in animals that produce one offspring only, occur oftener in those that are prolific, and most of all in birds, and specially in the common fowl.* This species is prolific, not only in laying eggs frequently, as the pigeon tribe does, but also in carrving manv fetations at once and in copulating at everj- season of the year. Hence also fowls lay many twin-eggs,

  • Tfiis sentence (which may be a note on 770 a 15 ff.) seems to be from the same author as the interpolation at 717 b 29 : the speed of birds' copulation obviously was a favourite point with him, but it has nothing to do either with this passage or with that in Bk. I. In the present passage, birds are introduced later by Aristotle (a 10).

since the fetations, on account of being situated close to each other, grow on to each other, just as many fruits sometimes do. Of these twin-eggs, those in which the yolks are kept apart by the membrane develop into two separate chicks, and there is nothing extraordinary about them ; those in which the yolks are continuous, with nothing to hold them apart, give rise to chicks that are monstrosities : they have one body and one head, but four legs and wings, the reason for which is that the upper parts of the body are formed out of the white and before the rest, the nourishment being dispensed to them from the store in the yolk, whereas the lower part (a) is formed afterwards, (6) its nourishment is uniform and homogeneous.*^ A snake, too, has been seen with two heads, and the cause is the same - this also is a class of animal which lays eggs and is prolific. Monstrosities occur less frequently, however, with snakes owing to the shape of their uterus, in which, on account of its length, the numerous eggs lie one after another in a row.** Nothing of this kind occurs with bees and wasps, because their offspring are laid in separate cells. With the common fowl, however, the opposite is the case - a fact which clearly goes to show that we are bound to hold that the cause of such things is in the material, since with other animals too they occur more frequently in those that are prolific. Hence they occur less frequently in human beings, for the offspring which these produce is as a rule one in number, and it is perfected by the time of birth, since even in this species the occurrence of monstrosities is more common in those regions where the women are

prolific - in Egypt, for instance." Monstrosities occur more frequently in goats and sheep, because they are more prolific ; and still more frequently in the fissipede animals, because animals of this sort are prolific and the offspring is not perfected when born (e.g., the dog) - most of these creatures' young, of course, are born blind. The cause why this occurs and the cause why they are prolific '^ must be stated later. But the way to the production of monstrosities has been already prepared for Nature by the fact that they generate offspring which, owing to its imperfect state, is unlike its parents : - for monstrosities come under the class of offspring which is unUke its parents. And that is why this particular accident extends its range to affect animals of that nature,** and, to bear this out, it is among these animals especially that metachoira ^ as they are called occur. These meiachoira are creatures which have in some respect undergone some " monstrous " affection, since the lack of any part or the presence of an extra part is such an affection. A monstrosity, of course, belongs to the class of" things contrary to Nature," although it is contrarv- not to Nature ki her entirety but only to Nature in the generality of cases.^ So far as concerns the Nature which is abrays ' and is hy necessity, nothing occurs contrary to that ; no ; unnatural occurrences are found only among those things which occur as thev do in the generality of cases, but which may occur otherwise. Why, even in those instances of the phenomena we are considering, what occurs is contrary to this particular order, certainly, but it never happens in a merely random fashion ; and therefore it seems less of a monstrosity because even that which is contrary to Nature is, in waVj in accordance with Nature (i.e., whenever the " formal " nature has not gained control over the " material " nature)." Hence, people do not call things of this sort monstrosities any more than they do in the other cases where something occurs habitually - as happens with fruit. Thus, there is a certain sort of vine - " smokv " * is the name some people give it ; - and if it bears black grapes they do not reckon it as a monstrosity, because it often and habitually does this. The reason is that it is intermediate in its nature between white and black, and so the alteration is quite small and not really contrary to nature, because it is not an alteration to a different nature.

These things, then, occur in the case of the animals which produce numerous young, because the numerous offspring which are produced hamper each other's being brought to perfection and also the movements which effect generation.

A puzzle may be raised about this production of Relation of numerous offspring and the redundance of parts, and and"deUci-^ the production of few or one offspring and the ency of deficiency of parts : sometimes animals are born the number having too many toes, some having one only : and ?[^°f*f"°^ the same vvith the other parts : some have too many ; stances some are mutilated ; some actually have two organs "'*'^" of generation, one male and the other female. This happens with human beings, and with goats especially. Goats are born which are called tragainai on account of their possessing both male and female organs of generation. We have also had an instance of a goat being born that had a horn on its leg. Alterations and deformations occur in respect of the inward parts too ; animals either lack certain parts, or have them in a mutilated form, or have too many of them, or in the wrong places. No animal, it is true, has ever been born without a heart, but there have been animals without a spleen, and \%ith two spleens, and Avith one kidney ; none without any liver at all, but certainly with an incomplete one. These phenomena are found in animals that are perfect " and living. We find, also, animals with no gall-bladder which naturally should have one * ; others with more than one. Instances have occurred of organs in the wrong places : the liver on the left side and the spleen on the right. These things, as I said, have been observed among animals which have reached perfect growth ; among newly born animals instances have been seen exhibiting great and varied confusion. Those which depart only slightly from the natural usually live ; those which depart more than that do not - i.e., when their unnatural conformation lies in the parts that control the creature's life.

The point about these which we have to consider is the following. Ought we to hold that one and the same cause is responsible for the production of a single offspring and the deficiency in the parts, and also for the production of man)- offspring and the redundancy in the parts, or not ? To begin, then, first of all, with the fact that some (b) Number animals produce many offspring, others a single one °' ° =>pring. only. Surely surprise at this is very reasonable, as it is the largest of the animals which produce one only, e.g., the elephant, the camel, the horse and those with uncloven hoofs ; of these, some are larger than

the other animals, some are really outstanding in respect of size. The dog, on the other hand, and the wolf, and practically all the fissipede animals produce many offspring ; even small animals of this class do so, such as the mouse family. The cloven-hoofed animals produce few offspring, except the pig, which is among those that produce many. As I said, this is surprising, because we might have expected the large animals to be able to generate more offspring and to produce more semen. But the very thing that surprises us is the reason why we should not be surprised. Their size is the very reason why they do not produce many offspring, because in animals of this sort the nourishment gets used up to supply the growth of the body, whereas in the case of the smaller animals. Nature takes away from their size and adds the surplus on to the seminal residue. Further, the generative semen of a larger animal must of necessity be greater in bulk," and that of the lesser ones small. Also, though many small ones may very well be formed in one place, it is difficult for many large ones to be. [To the intermediate sizes Nature has allotted the intermediate number. As for the fact that some animals are large, some smaller, and some intermediate, we have stated the cause of this earlier.] * For the most part it is the solidhoofed animals which produce a single offspring, the cloven-hoofed animals which produce few, and the fissipede animals which produce many. The reason for this is that for the most part the distinction of

sizes corresponds to these differences. At the same time, this does not hold good of all of them, because the reason for their producing few or many offspring is the size, great or small, of their bodies, not the fact that that particular kind of animal is cloven- or solid-hoofed or is fissipede. Here is a proof of this. The elephant is the biggest of the animals, but it is fissipede ; the camel, which is the next biggest, is cloven-hoofed. And it is not only among the animals that walk but also among those that fly and swim that the big ones produce few offspring and the small ones produce many ; and the cause is the same. Similarly, too, it is not the biggest plants that bear the most fruit.

We have stated why the nature of some animals is to produce many offspring, that of others to produce few, that of others to produce one only. So far as the puzzle which has now been mentioned is concerned, one might rather be justifiably surprised in the case of those animals Avhich produce many offspring, in view of the fact that animals of this sort, as we see, often conceive as the result of one act of copulation. Now it may be that the semen of the male contributes to the material <in the female) by becoming part of the fetation and by mixing with the semen of the female ; or it may be that it does not act in this way, but, as we hold, acts by concentrating and fashioning" the material in the female, i.e., the seminal residue, just as fig-juice acts upon the fluid portion of the milk ; but whichever of these views is right, what on earth is the cause why the semen does not turn out one single animal of a fair size, just as the fig-juice acts in our example, (but that instead several offspring are formed out of that residue) ? " [It is not di\ided up owing to its causing a certain quantity of milk to set, but the more the amount of milk into which it is put and the more fig-juice there is, so much the greater is the amount that gets curdled.] It is sometimes said that the regions of the uterus draw the semen, and on that account several offspring are formed, because these regions are several in number and because the cotyledons ^ are not a unity. This theory, however, has nothing in it, because often two embryos are formed in the same region of the uterus, and in the case of animals which produce many offspring, when the uterus is full of embryos, they can be seen lying in a row. This is clear from dissections. No ; what happens is this. When animals are being perfected, there is a certain size for each, a limit of bigger and smaller ; none \vill be formed either bigger or smaller than these sizes, but the excess or deficiency of size which they acquire as compared \\ith one another lie within this interval between the two limits, and thus it is that one human being (or any other animal) is formed bigger and another smaller. In precisely the same way, the seminal material out of which (the embryo) is formed is not unlimited in either direction - the amount of it can be neither bigger nor smaller than certain limits ; the embryo cannot be formed out of any casual amount of it. Thus, in the case of those animals which (on account of the cause stated) discharge more residue than is requisite for the principle juice, which appear to have formed part of a marginal note (c/. below 772 a 22 ff., with which passage they are obviously connected).

of a single animal, it is not possible that the entirety of this should be used to form one embryo ; on the contrary, as many are formed as is determined by the sizes proper to those animals. Nor again will the semen of the male or the dynamis " residing in the semen put into shape anything that is greater or less than the natural size. Similarly, if the male emits more semen, or more dynameis in the semen (in cases where the semen gets divided up), the greatest possible amount will not make anything bigger (than the natural size), but on the contrary will dri^ the material up ** and destroy it. The parallel case of fire and water shows this. An increase in the amount of fire does not mean that the fire increases the heat of the water in the same ratio ; on the contrary, there is a limit to the heat, and when that has been reached, you may increase the amount of fire, but the water does not continue to get hotter ; instead it evaporates more, and finally disappears and dfies up. Now since, as it seems, there must be some proportional relationship <^ between the residue of the female and that which comes from the male (this applies where the males emit semen), in the case of those animals which produce many offspring the male at the outset emits semen which is able, when divided up into portions, tcgive shape to a number of fetations, while the female contributes enough material so that a number of fetations can take shape out of it. (The parallel instance of milk, which was cited,** is not comparable, since, in the case of that which the semen's heat causes to take shape, not only quantity is involved but also quality, whereas in the case of the heat in the fig-juice and the rennet, quantity alone is involved.) * This, then, is the reason why in those

animals which produce many offspring the fetations are many in number and a single continuous one does not result instead of many - viz., a fetation is not formed out of any casual quantity : if there is too little or too much, none will be formed, because there is a definite limit set both to the dynamis of the material which is acted upon and to that of the heat which acts upon it. Similarly also in the case of those animals which are large and produce one offspring only, a large amount of residue does not give rise to a large number of offspring, for the same holds good : here too, the amount of the material and of that which works upon it are definite. So then they do not emit a larger amount of such material, owing to the cause already mentioned; and the material which they do emit is, in the natural course, just sufficient in amount to provide for a single fetation only. If ever more of it is supphed, then twins are produced. And hence, also, such creatures seem rather to be monstrosities, because their formation is contrary to the general rule and to what is usual. Man, however, has a footing in all the classes, producing one offspring, or on occasion, many, or few, though most naturally and normally one is the number : the production of many offspring is due to fluidity of the body and to heat, [since the nature of semen is fluid and hot ;] of few or of one, to the size of the body. And to this it is due also that in man alone among the animals is the period of gestation of variable length " : other animals have a single period, but with man there are several : children are born at seven months and ten months and at intermediate times, and indeed eight months' babies live, though less often than the others. The reason may be perceived from what has just been said ; a discussion of these matters is also to be found in the Problems." This, then, may be taken as the way in which we deal with this subject.

With regard to the redundance of parts which (c) Reason occurs contrary to Nature, the cause of this is the *^****same as that of the production of twins, since the cause occurs right back in the fetations, whenever more material gets " set " than the nature of the part requires : the result then is that the embrvo has some part larger than the others, e.g., a finger or a hand or a foot, or some other extremity or Hmb ; or, if the fetation has been split up, several come to be formed - ^just as eddies are formed in rivers ; here too, if the fluid which is being carried along and is in movement meets with any resistance, two selfcontained eddies are formed out of the original one, both of which have the same movement.^ What happei^s in the case of the fetations is on the same lines. The normal part and the redundant one are usually attached quite close to one another, although sometimes they are farther away because of the movement which arises in the fetation, and above all because (a) the excess of material recurs again at the place from which it was originally drawn off, and (6) the form which it has is derived from the part where it developed as a redundancy.*^ Some creatures develop in such a way that they have two generative organs [one male, the other female]. Always, when this redundancy happens, one of the two is operative and the other inoperative, since the latter, being contrary to Nature, always gets stunted so far as nourishment is concerned ; however, it is attached, just as growths (or tumours) are : these, like it, secure nourishment, although the date of their origin is later than that of the creature itself and they are contrary to Nature. The result of the fashioning agent " having gained the mastery, or having been completely mastered, is that two similar generative organs are formed ; if it to some extent gains the mastery and to some extent gets mastered, one is formed female and the other male, - for it comes to the same thing whether we apply this explanation of why one is formed female and another male to the case of the parts or to the animal as a whole. And wherever a deficiency occurs in such parts as e.g. an extremity or some other Umb, we must take it that the cause is the same as it is if the whole of the forming creature suffers abortion - and abortions of fetations frequently occur.

' [Redundant growths differ from the production of numerous offspring at a birth in the way which has been stated ; monstrosities differ from redundant growths in that most monstrosities are instances of embryos growing together.] (Alterations, too, occur ; in some cases they affect the smaller and less important parts.) whereas others are affected in a different way, i.e., if the alteration occurs in the larger parts, which have more to do with the control of the organism - e.g., some have two spleens, or several meaning borne by repara Ls at variance from that which it bears elsewhere in the discussion. The words may be an annotation intended for 773 a 13. The lines following (down to iiediaTafievrjs) seem to be a similar kind of summary, though more correct, and they too may be out of place or redundant.

kidneys. Also, there are instances of the parts changing their position, due to diversion of the " movements " and change of position of the material. Whether an animal which is a monstrosity is to be reckoned as one or as several grown together depends upon its " principle " ; thus, assuming that the heart is a part answering to this description," a creature which possesses one heart will be one animal, and any supernumerary parts will be merely redundant growths ; those, however, which have more than one heart we shall reckon as being two, which have grown together owing to the conjoining of the fetations.

It often happens, even with many animals that do (d) other not appear to be deformed and have actually reached formations. complete development, that some of their passages have grown together, and that others have been diverted. We know of instances of women in whom the OS uteri was grown together and continued so until the time arrived for the menstrual discharge to begin and pain came on ; in some, the passage burst open of its own accord, in others, it was separated by physicians ; and in some cases, where the opening either was forcibly made or could not be made at all, the patients succumbed. There have been instances of boys in whom the termination of the penis has not coincided with the passage through which the residue from the bladder passes out, so that the passage came too low ; and on this account they sit in order to pass water, and when the testes are drawn up they seem from a distance to have both male and female generative organs. There have also been instances in certain animals, sheep and others too, where the passage (for the residue) of the solid nourishment was grown together ; in fact, in Perinthus a cow was born which used to pass finely-sifted nourishment through the bladder. They cut its anus open, but it quickly grew together again, and they did not succeed in keeping it apart.

We have now discussed the production of few offspring and many, the nature of supernumerary or deficient parts, and also monstrosities.

In some animals superfetation " does not occur at V all, in others it does ; and among the latter some are f^^^' able to complete the nourishing of the fetations, others can sometimes do it and sometimes not. The reason why in some animals superfetation does not occur is that they produce one offspring only. Thus, it does not occur in solid-hoofed animals and in larger animals than these, because on account of their size the residue goes to the fetation and gets used up. All of these have large bodies, and large animals have large embryos, proportionate to their size ; that is why the embryo of an elephant is as big as a calf. Superfetation, however, does occur in animals which produce numerous offspring at a birth, because where there are more than a single offspring one is really a superfetation upon another. Of these animals, those that are large, such as man, complete the nourishing of the second fetation, if the second copulation has taken place not long after the first ; such an occurrence has in fact been observed. The reason is as already stated : Even in a single act of intercourse the semen discharged is more than sufficient, and this when divided up into portions causes the production of numerous offspring, one of which is later than another. When, however, the fetation is already advanced in its growth before the copulation takes place, superfetation sometimes occurs, but infrequently, because in women tRe uterus generally closes up during the time of pregnancy. But if ever it does happen (as in fact it has been known to do), the mother cannot bring the second one to completion, but ejects fetations that are very similar to what are known as abortions. The situation is comparable with that in the one-offspring animals, in which, on account of their size, all the residue is directed to the already existing embryo. So too it happens in these animals, except that in the former it happens straight away, whereas in these it happens when the embryo is already advanced in growth, because then their condition is similar to that of the one-offspring animals. Similarly, because man is by nature an animal which produces numerous offspring, and because there is something over and to spare as regards the size both of the uterus and of the residue (though not enough to bring the nourishing of a second embrvo to completion), women and mares are the only animals which admit copulation while they are with young. In women it is due to the reason already stated ; in mares it is due to the barrenness of their nature,^ and because the size of their uterus has something over and to spare - there is more than enough room for one, but not sufficient for a second fetation to be brought to completion. Also, mares are by nature prone to sexual intercourse because they are in the same predicament as females which are barren -

since this also is a condition due to there being no evacuation (which corresponds to the emission of semen in the male), and mares discharge extremely Uttle evacuation. Further, in all the \ivipara those females which are barren are prone to sexual intercourse, because they are in a similar condition to males when their semen is ready, collected together," but is not being emitted, the evacuation of the menstrual fluid in females being the emission of semen, since, as has been stated earlier, the menstrual fluid is semen that is unconcocted. Hence, too, those women who are incontinent in the matter of sexual intercourse, cease from their passionate excitement when they have borne several children, because once the seminal residue has been expelled from the body it no longer produces the desire for this intercourse. Among birds the females are less sexually excitable than the males because their uterus is close up by the diaphragm, whereas the males, on the contrary, have their testes drawn up internally,* so that if any class of such creatures tends naturally to abound in semen, they are always wanting to have sexual intercourse. Thus in females it is the descent of the uterus which encourages copulation, whereas in males it is the dra>Wng up of the testicles.

We have now stated the cause on account of which superfetation does not occur at all in some animals, why it does occur in others, and why these can sometimes bring the nourishing of the fetation to completion, sometimes not ; and what is the cause why of such animals some are prone to sexual intercourse and others not.

Some of those animals in which superfetation occurs are able to bring to completion the nourishing of their fetatioas even when there is a long interval between the copulations ; these are animals which (a)* belong to some kind which is abundant in semen," (b) are not large in bodily size, and (c) are among those which produce numerous offspring ; the reason being that (c)* because they produce numerous offspring their uterus is roomy, (a) because they are abundant in semen they discharge a great deal of residue by way of evacuation, (6) because they are not large in bodily size, but the evacuation exceeds by a larger measure the nourishment which goes to the fetation, they are able to cause young animals to take shape at the later stage too * and to bring their nourishing to completion. Also, in such animals the uterus does not close up, because there is a surplus amount of residue by way of evacuation. This has occurred to our knowledge in the case of women : in some women evacuation continues throughout the time of pregnancy. In them, however, it is contrary to nature (that is Mhy it injures the fetation) ; but in the animals we are discussing it is natural, because that is the way in which their body took shape from the beginning. The hare is an example of this. This is an animal in which superfetation occurs, for (b)* it is not one of the large animals, (c) it produces numerous offspring (since it is fissipede, and fissipede animals produce numerous offspring), and (a) it is abundant in semen. This is shown by its hairiness. It has an excessive amount of hair ; indeed, it has hair under the feet and inside the jaws, and is the only animal which does so. This hairiness is a sign that it has a large amount of residue ; and for this

same reason, too, men that are hairy are more prone to sexual intercourse and have more semen than men that are smooth. As for the hare, often some of its fetations are imperfect ; others of its offspring, however, it brings to birth in a perfected state.

Among the \'ivipara, some bring their young to VI birth in a perfect, some in an imperfect, state. To f^^^^j^g the former class belong the solid-hoofed and the at birth, cloven-hoofed animals, to the latter most of the fissipede animals. The reason for this is that the solidhoofed animals produce one at a birth, the clovenhoofed animals produce either one or two, in general,** and it is an easy matter to bring the nourishing of a few to completion. Those fissipede animals which produce their offspring in an imperfect state, all produce numerous offspring, and on that account while the fetations are quite young they are able to nourish them, but once they have advanced in growth and have attained some size their bodies are unable to bring the nourishing of them to completion, and so discharge them just as the larva-producing animals do,*" for indeed their young, like the larvae, are practically unarticulated when born, e.g., those of the fox, the bear, the lion, and similarly with some of the others ; moreover, practically all of them are blind, e.g., the ones just mentioned, and in addition those of the dog, the wolf, and the jackal. The only animal which produces numerous offspring that are perfectly formed is the pig ; thus it is the only one which has a footing in both classes : (a) it produces numerous offspring, as the fissipede animals do, but (6) it is a species which is cloven-hoofed and solid-hoofed - for soUdhoofed pigs exist, as we know. It produces numerous offspring because the nourishment available for

increase of size is secreted to yield seminal residue - since, for a solid-hoofed animal, the pig is not large in size ; at the same time and more commonly, it is cloven-hoofed, as though it were at odds with the nature of the solid-hoofed animals. On account of this, then, it not only produces sometimes one offspring, and two, but also and for the most part it produces numerous offspring, and it brings their nourishing to completion because of its fine physical condition : it is like a rich soil which can provide plants with sufficient and indeed abundant nourishment.

The offspring of some of the birds also are hatched in an imperfect state, and blind " ; viz. , of those which lay numerous eggs although they themselves are small in physique - e.g., the crow, the jay,* sparrows, and swallows '^ ; and of those birds which lay few eggs and yet do not provide in the egg abundant nourishment'* for the chick - e.g., the ring-dove, the turtle-dove, and the pigeon. And on this account, if the eyes of a swallow are deliberately put out while the bird is still young, they recover, because the injury is inflicted during the process of their formation and not after its completion ; that is why they grow and spring up afresh.* In general, then, the reason why offspring are born early before their formation is perfected, is because of inability to bring their nourishing to completion ; and the reason why they are born in an imperfect state is because they viz., the young skin. This may happen many times in succession if the experiment is repeated. The connexion between regeneration and embryonic growth is well grasped by Aristotle, but there are of course some animals, such as the newts, where the power of regeneration is retained throughout adult life (c/. H.A. 508 b 4> if.). are born early. This is plain, indeed, in the case of seven months' children : in some of them, vihen they are born, because they are imperfect, even the passages {e.g., those of the ears and nostrils) are often not yet fully articulated ; as the child grows, however, they become articulated. Many such individuals survive.

In human beings, more males are born deformed than females ; in other animals, there i§ no preponderance either way. The reason is that in human beings the male is much hotter in its nature than the female. On that account male embryos tend to move about more than female ones,** and owing to their moving about they get broken more, since a young creature can easily be destroyed owing to its •weakness. And it is due to this self-same cause that the perfecting of female embryos is inferior to that of male ones, (since their uterus is inferior in condition.* In other animals, however, the perfecting of female embryos is not inferior to that of male ones : they are not any later in developing than the males, as they arey in women, for while still within the mother, the female takes longer to develop than the male does ^ ; though once birth has taken place everything reaches its perfection sooner in females than in males - e.g., puberty, maturity, old age - because females are weaker and colder in ° Cf. H.A. 584 a 26 flF.

their nature ; and we should look upon the female state as being as it were a deformity, though one which occurs in the ordinary course of nature." WTiile it is >vithin the mother, then, it develops slowly on account of its coldness, since development is a sort of concoction, concoction is effected by heat, and if a thing is hotter its concoction is easy ; when, however, it is free from the mother, on account of its weakness it quickly approaches its maturity and old age, since inferior things all reach their end more quickly, and this applies to those which take their shape under the hand of Nature just as much as to the products of the arts and crafts. The reason which I have just stated accounts also for the fact that (a) in human beings twins survive less well if one is male and the other female, but (6) in other animals they survive just as well : in hiunan beings it is contrary to nature for the two sexes to keep pace with each other, male and female requiring unequal periods for their development to take place ; the male is bound to be late or the female early ; whereas in the other animals equal speed is not contrary to nature. There is also a difference between human beings and the other animals with regard to gestation. Other animals are most of the time in better physical condition, whereas the majority of women suffer discomfort in connexion with gestation. Now the cause of this is to some extent attributable to their manner of life, which is sedentary, and this means that they are full of residue ; they have more of it than the other animals. This is borne out by the case of those tribes where the women live a life of hard work. With such women gestation is not so obvious, and they find deUvery an easy business. And so do women everywhere who

are used to hard work. The reason is that the effort of working uses up the residues, whereas sedentary women have a great deal of such matter in their bodies owing to the absence of effort, as well as to the cessation of the menstrual discharges during gestation, and they find the pains of delivery severe. Hard work, on the other hand, gives the breath {pneuma) exercise, so that they can hold it ° ; and it is this which determines whether delivery is easy or difficult. All these things, then, as we have said, are in their way factors producing the difference in gestation as between women and the other animals ; but the chief one is that whereas in some animals there is but little menstrual evacuation, and in others no \isible evacuation at all, in women it is greater in volume than in any other animal ; and the result of this is that when it is not being discharged o\^-ing to pregnancy it causes them trouble (and indeed even apart from pregnancy, when the menstrual discharge fails to take place diseases are the result) ; and most women are troubled in this way rather more at the beginning, just after they have conceived, because although the fetation is able to prevent the evacuation, yet as it is so small it does not at first use up any amount of the residue ; afterwards, when it does take up some of it, it relieves the trouble. In the other animals, however, as there is but little of it, its amount is just right for the growth of the embryos ; and as the residues which obstruct the nourishment get used up, the animals are in better physical condition. The same applies to water-animals and to birds. The reason why some animals are no longer in good is supplied bv the holding of the breath." Cf. also 3/../. 703 a 18, 9 ; P. A. 659 b 18, 667 a 29 ; and App. B §§ 22 ff.

physical condition when the fetations are becoming sizable is that the growth of the fetation needs more nourishment than that afforded bv the residue. There are some few women Mho are in better physical condition during pregnancy. This occurs with those whose bodies contain but small amounts of residue, and as a result this is completely used up together with the nourishment that goes to the embrA'o.

We now have to treat of the mola uteri,'^ as it is VII called. This occurs in women occasionally only, but it *^° "^ does occur in some during pregnancy. Thev bring forth a " mola." It has been known to happen, in the case of a woman who has had intercourse and thinks she has conceived, that her figure has increased to begin with, and all the rest has proceeded as expected, but when the time for her delivery was at hand, she has neither brought anything to birth nor yet has the size of her girth decreased ; instead, she has continued in that condition for three or four vears, till she was seized with dysentery which brought her to a dangerous pass, and then she has produced a flesh}- mass, known as a " mola." Sometimes, also, this condition lasts on into old age and persists until death. In such instances the objects which make their way out of the body are so hard that it is difficult to cut them in two even by means of an iron edge. Well, I have spoken in the Problems ^ of the cause of this occurrence ; the case of the fetation in the womb is exactly the same as that of meat, when it is undercooked ; and it is due not to heat, as some people allege, but rather to weakness of heat (because it looks as though Nature in these cases suffers from

  • This reference cannot be found.


ARISTOTLE vareiv Kav ov ovvaaUai reAeiMaaL ovo eTnveivai 5 rfi yeveaei Trepas' Bio Kal crvyKaTayripdaKet ^ TToXvv ii.iiJi€V€L xP^vov ovT€ yap (hs rereXeafxevov^ ovd' (hs TTajJiTTav aXXoTpLov e)(€t ttjv (f)vcnv)' rrjg yap GKXrjporrjTos rj aTreipta alria- aTreipia yap ng Kal 7] fxcoXwais^ ecmv.

AiTopiav 8' ^X^*-' ^'â– '^ '^'- '"'ot' iv rots aAAot? oi);^t 10 ytverai l^cpoLg, el ixr] ri TTdpuTrav XeXrjdev. aiTLov 8e Bet voixll^etv on jxavov varepiKov eari yvvrj tcov dXXcov t,cpa)v, Kal irepl rds KaOdpaeis TTXeovdt,ei Kal ov hvvarai Trerreiv avrds' orav ovv €K SvarreTTTOv LKfxdSog avarfj to KUT^fxa, Tore yiverai rj KaXovixevTj pLvXr] ev rats yvvai^lv evXoyoig rj ^idXiara Tj fxovais'. VIII 15 To Se yaAa yiverai rotg OrjXeaiv oaa ^cooroKet ev avrots -x^piqcjiixov piev eig rov xpovov rov rod roKOVy rrjg yap rpo(f)'!^g )(dpiv avro rijg Ovpat,e erroL'qaev rj (f)vais rotg t,aioig, oiar ovr eXXeineiv avro ev rep jj^poi^oj rovrco ovdev ov6^ virepf^aXXeiv ovdev OTTep /cai (j)aiverai avpuTrtrrrov, dv p,-q ri 20 yevqrai irapd (f)vaiv. rots piev ovv dXXois l,a)ois, Sia ro rov ^(^povov eva rijs Kvi^aeajs elvai, Trpos rovrov dTravra rov Kaipov rj rreipis avrov' rots S' dvdpcoTTOts errel rrXeiovs oi xpdvoi, Kara rov Trpwrov dvayKatov vrrdpy^eiv Sio Trpo rdJv eTrrd pjr]vG)v dxpr]orov ro ydXa rats yvvai^i, rore 8' -^'817 yiverai ^ TcreXeofievov P : TereXeiionevov vulg. ^ /u.oA. codd.

" xPW'^f^^^ Me'v, because although it serves a purpose, it is also (11. 25 ff.) due to necessity in the sense that its formation follows inevitably from the circumstances, as Aristotle explains.

" See 772 b 5 ff . and H.A. 584 a 33.



^ome inability, and is unable to complete her woi'k and to bring the process of formation to its consmiimation ; that is why the mola lasts on into old age or at any rate for a considerable time, for in its nature it is neither a finished product nor yet something wholly alien) ; since the cause of its hardness is the lack of concoction, just as underdone nseat is another instance of lack of concoction.

But there is a puzzle here. Why is it that this phenomenon does not occur in the other animals . (unless of course it does, but has entirely escaped observation). We must take the reason to be that alone of all animals women are liable to uterine affections ; they produce an excess of menstrual evacuations and cannot concoct them ; and so, when the fetation has been " set," formed out of a liquid which is difficult to concoct, then what is called the mola is produced ; and thus it is not surprising that this takes place chiefly in women if not exclusively in them.

Milk is produced towards the time of parturition VIII in those female animals which are internally vivipar- ^'^'"^" ous, and it is (1) of a useful and serviceable quality," for Nature has provided animals with it so that they may nourish their young extei'nally, and she has so arranged that it is neither deficient nor excessive in any way at that time ; this we actually observe to obtain unless some accident contrary to nature occurs. In the case of the other animals, as there is but a single period of gestation, the concoction of the milk coincides with that ; in man, however, as there are more periods than one, the milk must of necessity be available at the earliest of the possible dates ; hence in women the milk, which is useless until seven months are up, at that point becomes useful and 467


776 a

25 -x^p-qaiiJiov. evXoyoj? he avjx^aivei /cat hia rrjv e'f dvdyKTjs alriav veTrefifjievov et? rovg reXevraiovg Xpovovs' TO jxev yap npajrov rj rod roiovrov TrepLTTcoixaTOS dnoKpLai? els rrjv rajv i/jL^pvcov dvaXioKerai yiveaiv TrdvTOJV 8' t^ Tpo(f)r] to yAvKVTaTov /cat TreTre/xjU-eVov, coctt' dcfiaLpovpLevrjs 30 TTJ? ToiavTTjs Svvdixecos dvdyKrj to Xolttov dXfxvpov yiveadai Kal SvaxvfJiov. reXeovpLevcjov Se twv KvrjjjidTwv TiXeov TO TTeptTTCOfJ-a TO 7T€piyLv6[xevov [eXaTTOV yap to dvaXiaKOjjicvovy Kal yXvKVTepov, ovK d(f)aipov[ji€vov ojxolcos tov €V7T€7ttov. ^ov yap ert els TiXdaiv tov €[x^pvov yiyveTai rj harrdvy), dAA' 35 els piiKpdv av^rjaiv, coartep eoTTjKos rjhrj Sid to 776 b reXog ^x^lv to efi^pvov eoTt ydp tls Kal Kvrj piaros TeXeioiais. hioTrep i^epx^Tau Kal /xerajSaAAet TTjv yeveaiv, wg c^ov ra avTOV Kal ovKeri Xapi^dvei TO pLT] avTov, €V c5 Kaipcp ylverai to ydXa ;^p')^crt/.ioi/.

Et? 8e TOV dvco TOTTov /cat Tovg /xaarous" avX 6 XeyeTai 8ta ri^v e^ ^PXV^ ra^tv t^j avoTdaecos â– TO jLtev ydp dvco tov VTTO^cJopiaTOS to Kvpiov tov ^a)ov^ ecTTt, TO he Kctro) tottos* Trjs Tpo(f)rjs Kal tov TTepLTTWjjiaTos, oTTcos" ooa TTopevTiKa rdJv ^(pujv ev ^ sic interpunxit Bussemaker.

^ pro ov yap en . . . xp^oiixov 776 b 3 habet S quoniam non indigetur ea. non ergo accipitur in illo tempore quod accipiebatur ante ex lacte. vide 777 a. 22-27.

  • Ttjs C(^ijs coni, Btf. * ronos P : om. vulg. â– - ■» -

" Cf. P. A. 676 a 35.

"" Aristotle here notes correctly that growth proceeds long after differentiation has ceased.

" i.e., as well as a creature which has reached an indepen 468


serviceable. But the fact that it is fiilly concocted at the final stages is due also (2) to another cause - the necessary cause, which is what we should expect, for, to begin with, the secretion of this particular residue is used up for the formation of the embryos ; and in every animal the nourishment is the sweetest ingredient they possess and the most concocted, so that when this sweet substance is drawn oiF, what remains is bound to be briny and ill-savoured.^ When, however, the fetations are approaching their completion, then there is more surplus, residue, because less of it is being used up, and it is sweeter, since the well-concocted residue is no longer being drawn off to the same extent : it is no longer being expended upon the moulding of the embryo, but upon the small growth which it is making,** as though the embryo had by now, being completed, reached a stationary point (since a fetation, too, has its point of completion.) " That is why it makes its way out, and changes over to anether process of formation as now possessing all that belongs to it, and it no longer takes what does not belong to it ** ; and that is the time when the milk becomes serviceable.

The milk collects in the upper part of the body, in the breasts, and this is accounted for by the original order of the body's construction. The part of the body above the diaphragm is the controlling part of the animal. (The part below is the place for the nourishment and the residue, in order that those animals which move about may have within them a dent state of existence ; and even the wind has its yiveais and <^iais (778 a 2), where see note ; and also cf. 737 b 9.

This remark is obscure, and the sentence may be an interpolation. See the parallel passage, 777 a. 22 S.


776 b

ARISTOTLE avroLS €)(0VTa ttjv tt^? rpocfjrj? avTapKeiav jxera^aXXj] Tous" roTTOvs- ivrevdev 8e /cat rj cnrepybariKT] 10 TTepirrcouL? aTTOKpu'erai Sia rrjv elp-qpievrjv alrtav €V TOt? /car' dpxo-S Xoyois- eari, 8e ro re tcov dppevojv 7T£ptTTCi>p.a Kal rd KaTap.rjvia rot? d-^Xeaiv atixaTLKrj? ^vaecjs- tovtov 8' dpx] Kat tcjv (jiXe^ojv 7] Kaphla- avrrj 8' iv rolg p-opiois tovtois. 8i6 TrpooTOv ivravda dvayKoiov ytyveadai rrjv 15 jxeTa^oXrjv eviSrjXov rrjg Toiavrrjs TrepLrrtoaecog. ScoTTep at re (f)a)vai ixera^dXXovai Kal roJv dppevojv KOL Tcov diqXeiaiv, orav dpx<^VTaL arrepixa (fiepeiv {t) yap dpxTj rrjg ^a>vr\s evrevdev dXXola 8e yiver at dAAotou ytvojxevov rov klvovvtos) , Kal rd nepl tovs jxaarov? a'lperai /cat rot? dppeaiv eTrihrjXcos y pidXXov 20 Se rot? diqXeaiv 8ta yap to /carat rriv eKKptatv yiveadai ttoXXtjv Kevos 6 tottos ytvcrai 6 tcov fjLaaTOJv avTals Kal aofx^os. oixoitO'S 8e Kai rot? /caroj TOVS /xaCTTOi)? exovatv. ytVerat p,ev ovv €TTLSr]Xo9 Kal 7) (jiojvrj Kal Td rrepl Toii? fxaaTovs Kal iv TOiS aAAot? ^ojot? Toi? ifXTreipoig rrepl eKaoTov 25 yevo'S, eVt Se tojv dv6pd>TTixiv hia^epet TrXelaTov. a'lTiov he to TrXeiGTrjv elvai ttjv TTepiTTcoaLv tols d-qXeai tovtois tojv 6rjX4cov Kal tols appeal twv dppevojv ibg /card fieyedo? [rat? jxev Tiqv tcov /cara[irjvta)v, rot? 8e ttjv tov atrepyiaTos 7Tp6eaLV^^} oTav ovv jXTj Xafi^avrj jxev to ep-^pvov ttjv ToiavTTjv ^ glossema : om. S.

« wSee 738 b 12 ff., 747 a 20. " i.e., upper.



sufficient independent supply of nourishment and be able to go about from place to place.) It is from here, too, that the seminal residue is drawn : the reason is given in the earlier chapters of our discussion." Both the residue in males and the menstrual fluid in females are of a bloodlike nature ; now the source of the blood and of the blood-vessels is the heart, which is situated in these ^ parts : therefore of necessity it is here that the change which this sort of residue undergoes must be first of all apparent. For this reason the voice of both male and female undergoes a change when they begin to produce semen, because the source of the voice is there, '^ and the voice changes its quality when that which provides its movement does so ; and further, the parts around the breasts rise up plainly in males as well as in females, though more so in the latter, since, as there is a plentiful excretion of matter downwards in females, the region of the breasts becomes empty and spongy ; and similarly in the case of those animals whose breasts are down below. Of course, this change in the voice and in the region of the breasts makes itself evident in the other animals as well - to those who have experience of each particular kind ; but the change is greatest in human beings. The reason is that women produce more residue than any other female animal, and so do men than other male animals, in proportion to their size [this refers to the excretion of menstrua] fluid and of semen respectively]. Thus, when the embryo no longer absorbs ' The heart, which is the apxri of the organism, is also in particular the source of all physical sexual characteristics ; see 766 a 30 ff., and note on 763 b 27. Cf. 787 b 15 et preced. See also App. B § 31.



776 b

30 aTToKpiaiv, Kco^vrj Se 6vpat,€ ^ahit,€iv, avayKoiov €Ls Tovs Kcvovs TOTTOvg ddpoi^eadai t6^ TreptTTCOfjia TTttv, odonrep av coaiv evri tcjv aurcav TTopcov. eari, 8' eKaarois tolovtos 6 rcbv p,aarC)v tottos 8t' dficl)OT€pas TO.? acTi'a? eveKa re rov ^eXriarov yeyovws tolovtos koI ef dmy/cr^S" ivravda 8e rjbri avviaTarai koL yiverai TreTre/x/xeVi^ rpo<j)rj rols 35 Repots, rrjs 8e rriijjeojs 'iari pukv Xa^elv rrjv elpr) 111 & ixlvTqv air Lav, can Se rrjv evavriav evXoyov yap Kat, /xet^ov oV ro cpi-^pvov TrAetco Xapifidvetv rpo(f)-qv, coCTre eXarrov rrepiyiveodat Trepl rov xpovov rovrov TTerrerat Se 6drrov ro eXarrov.

"On p.€V ovv earl ro ydXa rrjv avrrjv e^ov (j)vcn,v 5 rfj diroKpiaet e^ '^s" yiverai eKaarov, hrjXov, eipi-jrat 8e Kai rrporepov. rj yap avrrj vXt] rj rpe(f)Ovaa Kat e^ rjs avviara rrjv yeveaiv rj (f)VGis. eon 8e rovro 7] aipLanKT] vyporrjg roX^ evaip.oi'S' ro yap ydXa veTTepipevov alpid eonv, dXX ov hie(f)dappevov. JLpTTeSoKXrjs 8' r) ovK 6pda)g vireXapi^avev 7] ovk 10 ev pberrjveyKe iroir^uas d)9 ro ydXa^ p,7]v6s ev oySodrou SeKdrr] ttvov enXero XevKov.

aanporrjs yap Kat Treifjis evavriov, ro he ttvov aavporr^s ng eanv, ro he ydXa rwv TreTreppevcov. ov yivovrai he ovre OrjXa^opevai^ at Kaddpaecs ^ rovTois TO Z : tovto to A.-W. ^ [to yoAa] Diels : to atfj-a Kranz.

" Cf. Hippocrates, w. <j>vaios -rraiSlov 21 (vii. 512 Littre) Kal es Tas ixTjTpas 8e oXiyov epx^Tai 8ta Ttov avTecov <f>XePaiv Teivovai yap es tovs fiat,ovs Kai es tols fi'^Tpas ^Xe^ia ravTO. re Kat TrapanX-qoLa oAAa.



this residual secretion but at the same time prevents it from making its way out,, the whole of the residue is bound to collect in the empty spaces which are situated on the same passages.'* In each kind of animal the place around the breasts is just such an empty space, and it is so for both of the two possible reasons : it was formed such as it is (a) for the sake of the best, and (6) by necessity. And it is precisely here that the concocted nourishment for the young animals takes shape and is formed. As for its concoction : to explain that, either the reason stated * may be taken, or the opposite one, since it is just as reasonable to adopt the view that as the embryo is bigger it takes more nourishment, so that there is less nourishment left over at this particular time ; and a smaller amount takes less time to concoct.

It is clear that milk is possessed of the same nature as the secretion out of which each animal is formed (this has in fact been stated already) '^ : the material which supplies nourishment and the material out of which Nature forms and fashions the animal are one and the same.** And this material, in the case of blooded animals, is the bloodlike liquid, since milk is concocted, not decojnposed , blood. As for Empedocles, either he was mistaken, or else his metaphor was a bad one, when he wrote * how the milk is formed On the eighth moon's tenth day, a whitish pus.

No ; putrefaction and concoction are opposites, and pus is a putrefaction, whereas milk is to be classed as something concocted. In the natural course of

  • i.e., that the embryo requires less nourishment.

' At T39 b 26. " Cf. 744 b 35.

• Diels, Vortokr.^ 31 B 68.


777 a

ARISTOTLE /cara (fjVGiv, ovre avXXaufSdvovai dr)Xa^6fi€vai- kolv 15 avXXdfiojcnv, aTToa^evvvrai to ydXa 8ta to Trjv avTTjv elvai (f)vai,v tov ydXaKTO? /cat Tcbv KaTaixrjvicjov 7] he (f)vais ov Swarat TToAup^oetr ovTOjg WOT e7Tayi(j)OTepit,€iv , dXX av eTrl daTepa yevrjTai rj dnoKpLcns, dvayKoiov iwl OdTepa e/cAetTretv, ea;' pLT] yivqTai. (rt)^ ^caiov Kal irapd to (Ls ivl to ttoXv.

20 TOVTO 8 -^'§7^ vapd (f)vaiv ev yap rots' pirj aSurarot? dXXcog ^x^tv dAA' €vSexo[Ji€VOLs to /cara cf)vaLV iaTt TO (vs enl TO TToXv.

ViaXcjs Se StcopiCTTai rot? p^pdvot? Kal r) yeveais rj Tcbv t,(x)Uiv OTav yap 8ta to [xeyeOos fxrjKeTL LKavTj fj TO) Kvovfievo) rj Sta tov 6jji(f)aXov Tpo(f)ij, a/xa^ TO yaXa ytWrat ;;^p7]atjLtov' [rrpog ttjv yLvojievrjv 25 Tpo^Tjv]^ Kal ovK elaiovarjs Std tov ojicjiaXov Tpo(l>rjg* avjJLTTLTTTOvaiv at (^AejSes Trepl d? d KaXovfxevos ojJi^aXos ioTt x^TCtiVy /cat 8id raura /cat totc (TUjLt^aiVei 6vpat,€ rj e^oSos". IX 'Etti K€(f)aXr]v 8' i^ yeveais ecTTi tols l^cooig rrdaiv rj /card cf)vaLV Std to rd dvo) tou 6ji<j)aXov juet^co 30 ^X^'^ '^ ^ KaTCxi. Kadairep ovv ev t,vyoZ£ rjpTrjjieva^ e^ avTov perrei inl to ^dpog. e'^et 8e Ta jieit^uj rrXeZov ^dpog.

X Ot 8e XP*^^^^ V^ Kvqaecos eKdoTCp tcov ^ojoiv (hpiajxevoL Tvyxdvovaiv cos jiev errl to ttoXv Kara Tovg jStoD?" Tcbv yap xpoviojTepcov^ Kal rd? yeveaeis 35 e^Aoyov eti^at XP'^^^^^P'^^ ' ^^ P'V^ tovto y iarlv ^ Ti Peck. ^ dfj-a Platt : d\Xa vulg., seel. A.-W.

' seclusi ; om. S : npos ttjv tov yevo^ivov Tpo<f>T]v coni. A.-W. dXXd . . . yiyvTjTai (Z^*) . . . yevrjao^evrjv . . . avixirinrojaiv coni. Btf. (cum vv. 32-37 conferas 776 a 33 seqq.)

  • etacifft Siti TOV 6fJ.(j>aXov tj Tpo<f>T] P.



events, no menstrual evacuations take place during the suckHng period, nor do women conceive then ; and if they do conceive, the milk dries up, because the nature of the milk is the same as that of the menstrual fluid, and Nature cannot produce a plentiful enough supply to provide both ; so that if the secretion takes place in one direction it must fail in the other, unless some violence is done contrary to what is normal. And that ipso facto means something contrary to Nature, because in the. case of things which admit and do not exclude the possibility of being other than thev are, " normal " and " natural " are identical.

In the actual birth of the young animals we have another instance of good timing. When the nourishment that passes through the umbilical cord is no longer sufficient for the fetus, owing to its size, at that same time the milk is becoming serviceable, and when no nourishment is entering by way of the umbilical cord, then the blood-vessels to which the cord acts as a sheath collapse ; and for these reasons and at that time the exit of the fetus takes place.

The natural manner of birth for all animals is head IX first, because they have a larger bulk above the ^^OTn"head umbilical cord than below it, so that they are sus- foremosc. pended from it, as it might be in a balance, and the heavier side {i.e., the larger parts) goes down.

The period of gestation is of a definite length for X each of the animals, and normally the periods are ^p^Jift^onf proportionate to the animals' span of life ; after all, period. we should expect those which have a longer lifespan to take longer over their formation than others.

'" hie in Z spatium xi vel xii litterarum. * Xpovuorepwv P : â– xpovuav vulg.


ARISTOTLE 777 b aiTLov, dAA' wg cttI to ttoXv tovto avfx^e^rjKev to.

yap jLiet^cu /cat reAetore/ja rcov ivalfxcov t,coojv /cat L,waL TToXvv )(p6vov, ov fxevTOL TO. fjieit^ct} Trdvra jxaKpof^Lcvrepa. ttolvtcov yap aiSpcxJTTO's TrXeiarov^ ^fj Xpovov, TrXrjv iXecfiavros, oacov a^toTnarov exop.€V 5 T7]v TTeZpav eXarrov 8' iarl ro yevog to tojv avOpCOTTCDV 7} TO TCOV Xo(f)OVpCOV Kttt TToXXojV dXXoJV .

atriov 8e tov jjuev elvai p,aKp6^iov otlovv ^a)ov to KeKpdadai TtapairXirjaicos Trpos tov TrepiexovTa depa, /cat 8t' d'AAa af/XTTTttj/xar' drra <^ucrt/cd, nepl Sv vuTepov epovfxev, tojv 8e XP^^^^ "^^^ irepl ttjv 10 KVTjcnv TO jjieyedog tcov yewojfxevojv ov yap pa8tov iv oXiyM xpovco Xafx^dveiv ttjv TeXeiojoiv rds" jxeydXag avaTdaei? out€ t,a>o}v ovt€ tcov dXXcov los etTrelv ovdevog. BcoTrep Ittttol /cat to. avyyevrj ^cpa TOVTOL^ iXdTTCO t,covTa xpovov Kvei TrAetco XP^^^^' TCOV fiev yap ev'taucrto? d ro/cos", tojv 8e BeKafjirjvos 15 o TrAetcrros'. 8td t7]v avTrjv 8 atrtav TroXvxpovtos /cat d Td)^' eXec^dvTcov ecrrt rd/co?" hieTr^s yap r] KvqaLs 8td TT^v VTrep^oXrjv tov jxeyedovs.

EyAdycos 8e TrdvTCDv ol xP'^^^l /cat tojv /cy^aea/i' /cat* yevecreajv /cat tojv ^t'cov pLeTpeZodai j8odAovrat /card (f>vatv 7re/5td8ots'.^ Aeya> 8e Tiepiohov ^ TrXeZoTov P : TrXeico vulg. ^ »cai PZ* ; jcai rail' vulg.

' oAais add. P.

" This was apparent!}- a popular term meaning " bushytailed " ; see H.A. 491 a 1 where " the hphouroi as they are called " are the horse, the ass, the mule, etc. Cf. 755 b 19.

  • Cf. 767 a 30 ff., and Hippocrates, tt. adpwv vbdrcov totiojv, chh. 1-6 ; and for " blend," idem, it. Sioi'ttjs I. 33, and Ihtrod. § 40. Cf. 777 b 28, n.

<= See.De Imff. et brev. vit. 466 a 15 flf., P.A. 677 a 35 ff.



Still, this is not the reason for it ; only, this is what in fact normally occurs. The larger and more perfect of the blooded animals do certainly live a long time, but not all the larger ones are also longer-lived. Man is the longest-lived of them all except the elephant, so far as we have any rehable experience ; but human beings are smaller than the lophouroi " and many others. The reason why any animal is longlived really is that its " blend " is about the same in comparison with the air which is around it,* and there are other contributory factors inherent in its nature, which Mill be mentioned later on.*^ The reason for the various times of gestation is the size of the creatures which are generated. It is not easy for any large structure, be it an animal or anything else, almost, to reach its perfection in a short time. Hence horses and kindred animals, though they live a shorter time than men, have a longer time of gestation : in horses birth occurs at the end of a year, in the others, generally, after ten months. And for the same reason it takes a long time in elephants, whose gestation lasts two years owing to their excessive size.

•* In all cases, as we should expect, the times of Periods of gestation and formation * and of lifespan aim. ac- gov^il^ cording to nature/ at being measured by " periods." by cosmic By a " period '" I mean day and night and month and ^*" *'

    • The following important paragraph is not fully intelligible \*'ithout reference to Aristotle's theory of the universe and of movement. A collection of pa,ssages from other treatises relevant to this will be found in App. A and App. B § 11, which will provide the best commentary on the present passage. ' Or " birth."

' But Nature cannot always succeed in her aim ; see (78 a 5 below.


777 b

ARISTOTLE rjixepav Kal vvKra Kal jjLrjva Kal iviavrov /cat rovs 20 xpovovs rovs [xerpovfjievovs tovtols, en he ras" rr\s aeXiqviq'S TrepioSovs. elal Se Trepiohoi aeX-qvrjs TravcreXrjvo? re Kal i^Olais:^ Kal rcov fJiera^v -)(^p6vu)v at OL)(OTOiJiLaL- Kara yap ravrag avp-^dWei irpos Tov rjXiov 6 yap [xels Koivrj Trepiohos eariv apL<^o repojv. eoTL he rj aeX-qvr) apx^ ^'^ '^V^ Trpos rov 25 rjXiov Koivoiviav Kal rrjv [xerdX'qilfLV rrjv tov (/xjotos ytveraL yap ojanep dXXos â– ^Xtog eXdrTcov 8t6 avpL^aXXeraL els Trdaas ra? yeveaeis Kal reXenvaeis .

^ navaiXrjvos re koI (ftOloLS P : TravaeXrfVoi re Kai (jydiaeis villg.

" i.e., full moon, new moon, first quarter and last quarter. The meaning of avfj,pdXXei is obscure. The word occurs twice in Meteor., once (345 b 6) in an astronomical context, and once (376 b 24) in connexion with the rainbow, but neither passage helps to elucidate the present statement. It must, however, have some reference to the fact that the month is a " joint period " of moon and sun (see note below), so the rendering I have given may be offered as at any rate not inapproprTate. The importance here attached to the " bisections " of the times is found again in Theophr, De signls 6, where it is said that times and seasons {e.g., the year, the month, the day) are delimited by their bisections (at SixoTo^lai biopO^ovai rag u)pas), the bisections of the month being the full moons, the eighth days and the fourth days {tov fiijva eKaarov . . . Sixorofj-ovai . . . at re TTavaeXrjvoi Kal ,al dySdat /cat ai rerpaSe?, § 8) ; and changes of weather tend to coincide with these divisions (§ 9).

  • Periodo.i is really a circuit or cycle.

â– ^ This phrase, which he translates " the month being a period common to both," is excised by Platt on the ground that it gives no sense, and that " a period common to both sun and moon would be one which contained both the solar and lunar periods exactly." The phrase is, however, in Scot ; and, as it can be satisfactorily explained in view of the context, it must be retained. The explanation is this : the month, taken in the sense of a hmation, i.e., the period from one new moon to another, or the time required by the 478


year and the times which are measured by these ; also the moon's "' periods ' which are : full moon and waning moon, and the bisections of the intervening times," since these are the points at which it stands in a definite " aspect " with the sun, the month being a joint period ** of both moon and sun/ The moon is a "principle" on account of its association ^\-ith the sun and its participation in the sun's light, being as it were a second and lesser sun,** and therefore is a contributory factor in all processes of moon to go through all its phases once, is, literally and properly speaking, not a private period of the moon's, but, as Aristotle says, a joint period of the moon and sun, since it is the moon's position relative to the sun which determines how much of the moon's disk is illuminated. If the moon were self-luminous, there would l^e no phases, and therefore there could be no " phase-p)eriod." This is made even more clear if we consider that the moon does in fact possess a " period " proper to itself, pertaining to the moon's own actual motion, and not to the mere illumination of its surface by another body, and it is a period which differs in length from the lunation or " phase-period " - a fact which was probably better known to Aristotle than to some moderns. This is the period known in astronomy as the " sidereal period," i.e., the time taken by the moon to return again to its same apparent position among the stars - not to return into conjunction with the sun. The duration of this period is roughly 27 days 8 hours, as against an average of 29 days 13 hours for the " phase-period." Aristotle is therefore quite correct in stating that the " month," by which, as the context clearly shows, he means the " phase-period," is a joint period of the sun and, the moon. (I should, perhaps, apologize to astronomers for the un-astronomical term " phase-period," which I have used instead of " synodic period " in order to emphasize the point that phases are an incidental phenomenon, and not an essential concomitant of a synodic j)eriod.) "* This statement reappears in Theophr. De vent. 17 ij ae A'^vTj . . . otoi' dadeyijs rjXios iori, and cf. id. De signis temp. 5, where the moon is,described as " the sun of the night." 4-79


777 b

at^ yap dcpi-ior-qres Kal ijjv^eis ^J^^XP'- oupp^erpias TLvog TTOtovai TO,? yet'eaets", /xera Se ravra^ rag 30 (f)dopds' TOVTOJV 8' exovoL to Trepag Kal rrjg ^PXV'^ Kai TTJg reXevrrjs at rovraiv /civTyaei? tcov aarpuiv. woTrep yap Kai daXarrav Kal Trdaav opwfiev rrjv TOJv vypojv (jiVGLV laTapievr]v /cat fieTa^aXXovaav Kara rr^v rcDf TTvevpidriov Kivrjatv Kal ardacv, tov S' aepa Kal rd TTvevpLara Kara rrjv rod rjXiov Kal 35 Trjs creXi^vT]? irepiohov, ovTa> Kal rd Ik rovrojv (pvojJieva Kal rd iv rovroLS aKoXovdelv dvayKaXov 778 a Kara Xoyov ydp aKoXovdelv Kal rdg rdjv aKvpo repcov TTeptoSovg rat? rcbv Kvpicorepcov. ^los ydp rig Kal rrvevp^aros eari Kal yeveats Kal (j)diais. rfjs §€ TcDv darpoiv rovrojv Tr€pi<j)Opds ^dx d.v 5 krepat rives elev dpxct-i- f^ovXerat fiev ovv r] ^voLg rots rovriov aptdpLoZs aptOpLelv rds yeviaeis Kal rds reXevrds, ouk aKpi^ol Se 8ta re rrjv rrjs vXrjs ^ at P : Kal vulg. ^ ravras S.

" Cf. Phys. 246 b 4 to? ^ev yap tov acufiaTos, olov vyieiav Kat eve^iav, ev Kpaaei Kal avfifier pia depfiaiv Kal ipvxp<t>v riOefifv fj avTcov npos avra rojv evros rj -rrpos to irepiexov (cf. Ill b 7, and 767 a 30 ff.)* 6p.oio)s Se . . . koI to? aXXas aperas Kal KaKias. The language used in the context of this passage is very similar to that oi Eth. Nic. Bk. II (dealing with the doctrine of " the mean "), where it is stated that the moral dpeTai also are produced and preserved by rd ovfifitTpa (1 104 a 18), whereas they are destroyed by excess and defect, just as the corresponding physical dperal are.

  • Cf. Meteor. 339 a 21 eoTi S' e^ dmy/cT/s cwvexris ttcds oStos [i.e., 6 -nepl Trjv yrjv Koafios, the sublunary world] rals avw <l>opais, cuoTe Trdaav avrov ttjv Swa/ntv Kvjiepvdadai SKeWev . . . coare t(Jl>v avp-^aivovrcov nepl avrov nvp fiev Kal yijv Kal rd avyyev^ TOVTOiS <os ev vXrjs eiSet, tcov yiyvofxevcov aina xpr) vofj-i^eiv, . . . TO 8' ovTWS airiov to? odev rj Trjs Kivi^aews dpxTj Trjv tojv del Kivovfxevcov aiTuxreov bvvafiiv.



generation and perfecting. As we know, it is heat and cooling in their various manifestations which up to a certain due proportion " bring about the generation of things, and beyond that point their dissolution : and the Uniits of these processes, both as regards their beginning and their end, are controlled bv the movements of these heavenly bodies. Just as we observe that the sea and whatever is of a fluid nature remains settled or is on the move according as the winds are at rest or in motion, while the behaviour of the air and the winds in turn depends upon the period of the sun and moon,*^ so too the things which grow out of them and are in them are bound to follow suit (as it is only reasonable that the periods of things of inferior standing should follow those which belong to things of higher standing) since even the ^-ind has a sort of lifespan ** - a generation and a decline. And as for the revolution of these heavenly bodies, there may very well be other principles which Ue behind them.* Nature's aim, then, is to measure the generations and endings of things by the measures of these bodies, but she

  • Cf. 738 a -20 : the times about new moon (at rwv yL-qvotv owoSot) are cold l)ecause of the faiHng of the moon, and for the same reason they are stormier than the middle points of the month : a precisely similar statement, using exactly the same terminology that Aristotle uses, is found twice in Theophr. De vent is 17 and De slgnis 5: in the latter passage the cause given is that the moon's light fails "' (aTroAei'irei) from the fourth day of the waning moon until the fourth day of the new moon, and this apparently is the time covered by at avvohoi. tuiv fXT)vu>v. The way in which the sun determines the weather is discussed at Meteor. 359 b -26 if.

•^ Cf. above, 776 b 1, and Plato, Timaeus 91 b, c, where the course of a disease is compared with the lifespan of a living organism. ' See, e.g., De caelo I, II.

R 481

ARISTOTLE aoptariav /cai Sto. to yiveadai ttoXKcis dp)(o-?, ol ras yeveaeis ras Kara (f)vaLv /cat ras ^dopa? ifXTrohil^ovaai TToXXaKLg aXriai tcov irapa (jtvaiv avp, TTLTTTOVTCDV €.laiv.

10 Wepl fxev ovv ri^g eacoOev Tpo^T]s rCov t,a)U)v /cat Ti]? dvpa^e yeveaecog etprjTaL, /cat x^P^ Trepl cKaarov /cat kolvjj irepl ttolvtcov.^ ^ Trepl Se (re Y) rwv 8ia<l)opcov als (as Z, al Y) Sia^epoucrt to. fiopia ru)v l^aicov, Koi fidXiara to toiovto (toiovtov P) avfi^aiveiv Trepl Toiis dudpiunovs addunt PYZ : amplius YZ oaa ixev (fiev ovv Z) exovai fiopia rd ^oia Trdvra Kal rwv evrds koX rdv cktos. totum vertit 2, et 778 a 10 initium facit libri insequentis.



cannot bring this about exactly on account of the indeterminateness of matter and the existence of a plurality of principles which impede the natural processes of generation and dissolution and so are often the causes of things occurring contrary to Nature.

Very well : we have now spoken of the nourishment of animals within the parent, and of their birth and exit into the outer world ; and we have dealt with each kind separately as well as generally with them all."

  • â– Some Mss. have an addition here, for which see opposite.


E 778 a 16 I Tlepl 8e roJv Tradrjfidrojv of? hi.a<f)€povai to. jxopLa Tcov ^(Lcov decop-qreov vvv. Xeyco 8e to. roiavra TTad-qjxara tcov p.optojv, otov yXavKor-qra ofXfxaTojv Kal fieXaviav, /cat (fxjovrjs o^vnqra /cat 20 ^apvri)Ta, /cat )(^p(vp,aTos [rj aoofJLaros] /cat rpL)(cov f] TTTepwv hia^opag} rvyxo-vet Se twv tolovtojv evca jiev oAot?^ V7Tdp)(ovTa tols yeveatv, evia? 8' OTTOJS ervx^v, olov /LtaAtcrr' eVt rcbv dvdpcoTTCov rovTO GVjJi^e^r^Kev. €tl 8e Kara rds tcov rjXLKicov* jjLeTa^oXds TO, fiev Trdaiv 6[jlolcjos inrdp^et Tot? 25 t,cooL9, Ta 8' VTTevavTLOJ?, (Larrep Trepi re cf)COvds /cat Trept TpL)(dJv ;(poav ra yitet' yap ou TToAtourat Trpo? TO yrjpas eTTiS-qXcog , 6 8' dvdpcoTTOs fidXiOTa TOVTo 7Taa)(ei tcov dXXcov ^cocov. Kal Ta jxev evdvs dKoXovdel yevojJievoLg, Ta 8e npoLovarfs Trjg i^At/ctas" ytVerat 87^Aa /cat yrjpaaKovTcov. vepl 8e* Toiircuv 30 /cat TCOV' TOLOVTCOV TrdvTCOV OVK€Tt TOV aVTOV TpOTTOV Set vofJiit,€LV etP'at tt^? atrtas. ooa yap p,i^ t"^? 0uCTCct)? [epya]* KOLvrf fMrjd^ tSca tov yevovs CKdaTov, ^ ^ ocofuiTos seel. Bekker, xP<^y^o.To^ rj Sep^iaros coni. Platt ; fortasse scribendum xP^l^o.ros fxera^oXas {alterationem color is 2). mox r) Kal -nrepiuv SY ; 8ia<j>opds P, 8ia(f>opdv viilg.

^ oAtyots P. ' Ivia Peck (idem Richards) : evioLS vulg.

  • raiv rjXiKicjv PZ* : rijs ijAi/ciaj vulg. : -qXiKias SY.

5 Si) P. « cm. Z ; seel. A.-W. ' Ko.vd Btf.


Book V

We must now study the " conditions " in respect I of which the parts of animals differ. I mean such (^^^ndary conditions of the parts as the following : blue and sex-chardark colour of the eyes, high and deep " pitch of the voice, and differences of colour and of hair or feathers. Some of these conditions are found throughout certain classes of animals ; some occur irregularly, and a striking instance of this is afforded by the human species. Further, there are some conditions, accompanying the changes in the times of Ufe, which occur in all animals alike, but there are others which are divergent in different animals, as, e.g., those which have to do with the voice and the colour of the hair : thus, some animals do not go noticeably grey towards old age, whereas man is affected by this condition more than any other animal. Again, some of these conditions come on immediately after birth, others make themselves noticed as age advances, or in old age. When we come to consider these conditions and all others like them, we must not supp)ose that the same sort of cause is operative as before, for there are certain conditions which are not characteristics belonging to Nature in general, nor pecuharities proper to this or that particular class of animal ; and whatever the quaHty of such conditions may be, in no instance is either its existence or its formation " for the sake of something." " Thus, the existence and the formation of an eye is " for the sake of something." but its being blue is not - ^unless this condition is a peculiarity proper to the particular class of animal. And further, in some cases this condition has nothing to do with the logos * of the animal's being ; instead of that, we are to assume that these things come to be by necessity, and so their causes must be referred back to the matter and to the source which initiated their movement."^ Remember what was said at the beginning, at the outset of our discussion.** So far as the regular, definite products of Nature's hand are concerned, whatever a thing may be as regards its quality, the reason why each thing is of such or such a quality is not because it gets formed such while it develops ; the truth is that things get formed such because they are such," for of course the process of formation takes its lead from the being, and is for the sake of that ; the being does not take its lead from the process.^ The old physiologers, however, thought the opposite, because they did not see that the causes were numerous ; they recognized only the Material Cause and the Motive Cause (and even these they did not clearly distinguish), whereas they paid no attention to the Formal Cause and the Final Cause?) Each thing, then, i* " for the sake of something," ^

while as regards their process of forviation, all those characteristics which are contained in its logos, or are subservient to some end, or are an end in themselves - these come to be formed on account of this Cause " as well as the remaining Causes. Other characteristics, however, are formed during the process which do not fall under the headings just given, and the cause of them is to be looked for in the movement, i.e., the process of formation - we must assume that they acquire their differences within the actual process of construction. Thus (to take an example) X will of necessity possess an eye (because that characteristic ^ is included in the essence of the animal as posited), and it will - also of necessity - • possess a particular sort of eye, but the latter is a different mode of necessity' from the former,** and is derived from the fact that it is naturally constituted to act and to be acted upon in this or that way.* Having settled these points we may proceed to sleep. those which immediately follow. First then : the habit of the young of all animals, especially those of animals which bring forth their young imperfect, once they have been born, is to sleep, because thev are in fact continually asleep within the parent from the time that they first acquire sensation. There is, however, a puzzle concerning their original formation, which is this : which state exists first in animals, sleep or waking ? From the fact that, as we see, they become more awake the older they get, it seems reasonable to suppose that the opposite state, sleep, is the one that exists at the beginning of their formation - and also from the fact that the transition from

not-being to being is effected through the intermediate state, and sleep would appear to be by its nature a state of this sort, being as it were a borderland between li^^ng and not liWng : a person who is asleep would appear to be neither completely nonexistent nor completely existent : for of course it is to the waking state par excellence that life pertains, and that in virtue of sensation. On the other hand, assuming it is necessary that an animal should possess sensation, and that it is first an animal at the moment it has first acquired sensation, we ought to regard its original state not as being sleep but something resembling sleep - the sort of state that plants also are in ; indeed the fact is that at this stage animals are living the Ufe of a plant. Sleep, however, cannot possibly pertain to plants, because there is no sleep from which there is not an awaking, and there is no awaking from the condition in plants which is analogous to sleep. An}"\vay, young animals must of necessity sleep for the greater part of the time because the burden of their groMth and the consequent weight is laid upon the upper regions of the body." (We have explained elsewhere * that such is the cause of sleep.) All the same, animals are clearly found to wake even within the uterus, as is shown by dissections and by the case of the Ovipara ; afterwards they immediately drop off and fall asleep again. That is why after birth as well they spend most of their time asleep.

Infants do not laugh while they are awake, but they both laugh and weep while they are asleep, for of course sensations occur in animals during sleep as regions of the body becoming weighed down by various hot substances which are carried up to them.

well as in waking hours, and this includes not only what we call dreams but something more besides ; thus persons who get up while they are asleep do quite a number of things Aithout dreaming at all. There are those who get up while asleep and walk about and can see as well as anyone awake. The reason is that they are aware through their senses of what is going on, and though they are not awake, still this awareness is different from that of a dream. Infants, it would seem, have not yet acquired the art of being awake, if we may put it so, and thus both their sensations and their life go on during their sleep by force of habit. As time wears on, and the scene of their growth shifts its ground to the lower parts of the body, at this stage they wake up more and spend the greater part of their time awake. To begin with, however, infants spend more time asleep than any other animal, because they are born in a more imperfect condition than any other perfected •* animal and have made their advance in growth chiefly in the upper part of the body.

The eyes of all infants are bluish immediately after Colour of birth ; later on they change over to the colour which ^â– ^' is going to be their natural colour for hfe. In the other animals this does not occur noticeably, and the reason is that their eyes exhibit more singleness of colour : thus, cattle have dark eyes ; all sheep have palUd ^ eyes ; another class of animal ^^•ill all have greyish-blue, or blue, eyes ; some have " goat'seyes," '^ as indeed the majority of goats themselves have. The eyes of human beings, however, show fissipede animals, such as the dog, produce them " imperfect," e.g., they are born blind.

in practice a multiplicity of colour ; some are blue, some greyish-blue, some dark, some yellow. Hence in the case of the other animals, just as the individuals of anv class do not differ from each other, so they do not differ from themselves," the reason in both cases being that they are not naturally constituted to have more than one colour. The greatest multiplicity of colour, however, among the other animals is found in the horse ; indeed in some horses the two eyes are of odd colours.^ Xo other animal is noticeably affected in this way, though some human beings are.

Well, then, for the fact that in the other animals, young or old, no noticeable change occurs, whereas in infants a change does occur, we must consider simply this to be a sufficient cause, viz., that in animals this part is single-coloured, in human beings multicoloured ; while for the fact that the young have bluish eyes and not some other colour, the reason is that their parts are weaker than those of adults, and blueness is a form of weakness.

We must now determine the general question of why eyes differ, and what is the cause why some are blue, some greyish-blue, some yellow, some dark. There is a theory, stated by Empedocles, that blue eyes are fiery in composition, while dark ones contain more water than fire, and that therefore blue eyes are not keen-sighted in the daytime owing to their deficiencv of water, and the other ones suffer in the same way at night owing to their deficiency of fire. But if we ought in point of fact "^ to posit that the sight,** in all cases, consists of water, not of fire, then ' This is Aristotle's own theory ; see De anima 425 a 4 ; De aensu 438 a 5, 13 if., b 5. For details, see App. B § 28. ** i.e., the organ of sight, as often in this discussion.

Empedocles' statement is incorrect. And besides, another method is open for explaining the cause of the colours. But assuming the correctness of what was said earlier in the treatise Of the Senses, and before that in the treatise Of the Saul,'^ i.e., that the sense-organ of sight is composed of water, and also the correctness of the cause there assigned for its being composed of water and not of air or of fire, then we should take it that the following is the cause responsible for the phenomena just described. Some eyes contain too much fluid, some too little, to suit the right movement,^ others contain just the right amount ; and so those eyes which contain a large amount of fluid are dark, because large volumes of fluid are not transparent ; those which contain a small amount are blue. (Sea-water is a parallel instance. Transparent sea-water appears blue, the less transparent appears paUid, and water so deep that its depth is undetermined is dark or dark blue.) Eyes intermediate between these two extremes differ merely by " the more and less." " We ought to suppose that to the same cause is due Keenness the fact that blue eyes are not keen-sighted during °' ^'*'"" the daytime nor dark eyes at night. Blue eyes, on account of the small amount of fluid in them, are unduly set in movement by the light and by \-isible objects, in respect both of fluidity and of transparency. It is, however, the setting in movement of this part in respect of its transparency that constitutes sight, not in respect of its fluidity.'* Dark eyes are set in movement less owing to the amount of

fluid which they contain, for the Hght is weak during the night, and, in addition to that, fluid generally is not easily set in movement at night. To obtain the best results, it must avoid both (a) not being set in movement at all and also (6) being set in movement too much in respect of its transparency, because the stronger movement ousts the weaker." That is why people who have been looking at strong, brilliant colours, or who go out of the sunlight into the dark, cannot see : the movement which is already present in their eyes is so strong that it precludes the movement which comes from without. And in general, neither strong sight nor weak sight can see bright things because the action undergone by the fluid in the eye is unduly intense - i.e., the fluid is set in movement unduly. This is borne out by the ailments besetting either kind of sight. Cataract tends to attack the blue-eyed more than the dark-eyed, nightbUndness ^ as it is called attacks the latter. Cataract is a sort of dryness of the eyes, and that is why it occurs oftener in the ageing, as these parts (the eyes), like the rest of the body, become dry towards old age. Night-blindness is superabundance of fluid, and that is why it tends to attack younger people : their brain is more fluid. The best sight of all is that which is midway between a large amount and a children are bluish ; and the reason given for blueness at 780 b 1 (and 779 b -29) is the small amount of fluid. At 779 b 1 1 , however, the reason given for bhieness is weakness (weakness is explained at 780 b 7 as being due to lack of concoction of the fluid) ; and at 780 b 8 undue thinness of fluid is said to " be equivalent " {Trjv avTTjv exet Stivafxiv) to a small amount of fluid. We may deduce, therefore, that a large amount of thin fluid is equivalent to a small amount of fluid ; at any rate, this seems to be the only way of reconciling Aristotle's apparently contradictory statements.

small amount of fluid, because on the one hand it is not so small in volume that it gets disturbed and so hampers the movement produced by the colours, nor on the other hand is it so large in volume that its movement is rendered difficult.

These are not the only causes of dullness and keenness of sight. In addition to them we must mention the nature of the skin upon what is known as the pupil. This skin should be transparent, a condition which must of necessity be satisfied by skin that is thin, and white, and even - thin, in order that the movement that comes from without may take a straight course ; even, so that its \\'rinkles shall not produce a shadow (the reason why old people do not have keen ^ision is that the skin in the eyes, like that elsewhere, gets wrinkled and thicker in old age) ; white, because that which is black is not transparent, non-transparency being precisely what blackness is ; and that too is why lanterns cannot give any hght if they are made of black skin.

In old age and disease, then, these are the causes OMing to which the sight is not keen ; in children, however, it is the small volume of fluid which makes the eyes appear blue to begin with.*' And oddcoloured eyes occur more often in human beings and horses than other animals for the same cause that human beings are the only animals that go grey and the horse is the only one of the remainder whose hairs noticeably M'hiten in old age : - Greyness is a weakness, viz., a lack of concoction, of the fluid in the brain ; so is blueness of the eves ; since unduly thin ^ fluid and unduly thick fluid are the equivalent "^ respectively of a small amount and a large amount of

  • For exft Bwaiuv, cf. 733 b 15 784 b 14, and Introd. § 26.

fluid ; therefore, whenever Nature cannot make the fluid in both eyes tally, either by concocting it or by not concocting it in both, but instead of that concocts it in one and not in the other, the result is odd-coloured eyes.

The fact that some animals are keen-sighted and Two senses , , /. r> II 1 >> of "keen.

others not is due to two sets ot causes, tor keen here has practically two meanings (so it has when appUed to hearing and smelling). Thus, keen sight means (a) ability to see from a distance, (6) distinguishing as accurately as possible the differences " of the objects which are seen ; and these faculties do not occur together in the same persons. The man who shades his eye with his hand or looks through a tube will not distinguish any more or any less the differences of colours, but he will see further ; at any rate, people in pits and wells sometimes see the stars. So that if any animal has a considerable projection over his eyes, while the fluid in his pupils is not pure nor suitably proportionate to the movement coming from without, and if the skin on the surface of them is not thin, then that animal will not have accuracy of vision in so far as differences of colours are concerned, but he will be able to see from a distance (just as he would from close quarters) better than animals which though they have pure fluid in their eyes and a pure covering round it, yet have no projecting brow at all in front of their eyes. The reason is that (a) the cause of being keen-sighted enough to distinguish the differences <of colour) lies in the eye itself, since just as quite small stains are plain and distinct on a pure, clean shirt, so quite small movements are plain and distinct in a pure, clean sight" and they give rise to sense-perception. As for (6) the ability to see things at a distance, and the fact that the movement coming from objects at a distance succeeds in reaching into the eyes, the cause of this is the position of the eyes. Animals with prominent eyes do not see well from a distance, but those with sunken eyes placed in a hollowed recess are able to see things at a distance, because the movement does not get scattered into space but follows a straight course. It makes no difference to this which of the two theories of sight we adopt. Thus, if we say, as some people do, that seeing is effected " by the sight issuing forth,"* then on this theory, unless there is something projecting in front of the eyes, the " sight " of necessity gets scattered and so less of it strikes the object, with the result that distant objects are less well seen. If we say that seeing is effected " by a movement derived from the visible object," then on this theory, the clarity with which the sight sees will of necessity vary directly as the clarity of the movement : distant objects would be 'seen best of all if there were a sort of continuous tube extending straight from the sight to that which is seen, for then the movement which proceeds from the visible objects would not get dissipated ; failing that, the further the tube extends, the greater is bound to be the accuracv with which distant objects are seen.

These, then, shall be the causes which we assign to explain the different sorts of eyes.

The same situation is found in connexion with II two other senses - hearing and smell - as with siffht. Keenness of rr- 1 1 11 << 1 >> / P Smell and lo hear and to smell accurately means (a) to Hearing, perceive as well as possible all the differences in the

objects perceived, (6) to hear and smell from a distance. As for (a) the abihty to distinguish the differences well, the cause of this is the sense-organ, just as it is in the case of sight, i.e., it must be pure and clean itself, and so must the membrane round it." [ For the passages of all the sense-organs, as is stated in the treatise Of Sensation, run to the heart, or to the counterpart of it in animals which have no heart. Now the passage of the hearing, since the senseorgan of hearing consists of air, terminates at the point where the connate pneiima causes in some the pulsation, in others, the respiration [and inspiration]. This, too, is why we are able to understand what is said and to repeat what we have heard, for whatever the character of the movement was which entered through the sense-organ, the character of the movement caused by means of the voice is the same in its turn - they might be two impressions from one and the same die. So, if you have heard a thing, you can utter it. Again, people hear less well while yawning and breathing out than they do while breathing in. The reason is that the principle of the sense-organ of hearing is situated upon the part * that is concerned with the pneuma, and it is shaken and set in movement when the organ sets the pneuma in movement [since the organ gets set in " Cf. De anima II. 420 a 13 : we can no longer hear if the membrane is damaged which encloses the air in the ear, any more than we can see if the skin on the pupil of the eye is damaged.

movement while it is causing movement]. The same condition occurs during damp seasons and in damp cUmates, and the ears appear to get filled with pneuma, because the principle is situated close by the region that is concerned with the pneuma. Thus, accuracy in distinguishing the differences both of sounds and smells depends upon the purity of the sense-organ and of the membrane upon its surface, for all the movements turn out plain and distinct in such cases also, just as in the case of sight.] (6) Perception from a distance, too, [and failure to perceive from a distance] occurs in the same way as in the case of sight. Thus, animals which have as it were channels passing through the parts concerned and projecting well out in front of the sense-organs can perceive from a distance ; and that is why animals which have long nostrils, hke the Laconian hounds, are keen-scented : the sense-organ is set well back in the interior, and therefore the movements which come from a distance do not get scattered but take a straight course, which is just what happens when we shade our eyes with the hand. Another similar case is that of those animals which have ears that are long and jut well out Uke the cornice of a house - some quadrupeds have ears of this sort - and a long internal spiral passage ; these long ears, hke the long noses, catch the movement a long way off and transmit it to the sense-organ.

cised at a distance is possessed by man to a lesser degree, in proportion to his size, than almost any other animal ; on the other hand, he is better than any of them at accurately perceiving the differences in the objects perceived. The reason is that in man the sense-organ is pure and least earthy and corporeal, and besides that, nature has given him, for his size, the thinnest skin that any animal has.

Nature has brought off a clever piece of work in the seal, too, which, although it is a viviparous quadruped, possesses no ears but passages merely. The reason is that it spends its life in a fluid medium. The ear is a part of the body which is an addition made to the passages in order to safeguard the movement of the air" which comes from a distance, and therefore it is no use to the seal ; indeed it would actually be a hindrance rather than a help, because it would act as a receptacle for a large volume of water.

This concludes our remarks about sight, hearing and smell.

The various kinds of growths of hair. - In human III beings these differ in the same individuals at different ^'an«t'«s periods of life, and they differ also in comparison with the other animals that have hair. Practically all the animals which are internally \iviparous have hair ; I say " all," because the spines which some of them have on the body must be considered as being a kind of hair, e.g., the spines of the hedgehog ** and any other such viviparous creature. Hair exhibits the following differences : it may be hard or soft, long or short, straight or curly, plentiful or

scanty ; beside this, it also shows diflPerences of colour : it may be white or black or any shade between these two. Some of these differences are also exhibited by the hair according to the various times of life, youth and more advanced age. This is noticeable chiefly in the case of human beings. Thus the hair gets shaggier as age advances, and some people go bald in front. Children do not go bald, nor do women ; men do, however, when they begin to get on in years. In human beings, the hair on the head turns white as age approaches ; in other animals, however, this does not noticeably occur : the horse is the one which shows it most. Human beings go bald on the front of the head, but they go grey first on the temples ; none however goes bald either here or at the back of the head. As for those animals which have no hair but the counterpart of hair instead (thus, birds have feathers, and the fish tribe have scales) - in them some conditions of the kind described occur in a corresponding way.

We have already stated in the treatise on the Causes of the Parts of Animals " the purpose for the sake of which Nature has made hair in general and provided animals with it. The business of our present investigation is to show what are the pre-existing circumstances, what are the factors of necessity, on account of which the particular sorts of hair occur.

The chief cause, then, of its thickness and thinness is the skin ; which in some animals is thick, in others thin ; looseknit in some, compact in others. A contributory cause is the difference of the fluid present in it : in some this is greasy, in others watery. In general, of course, the fundamental nature of the skin is earthy in substance : being on the surface of the body it becomes solid and earthy as the fluid evaporates off. Now the hair and its counterparts are formed not out of the flesh but out of the skin [as the fluid in them evaporates and exhales ; thus thick hair is formed out of thick skin and thin hair out of thin skin].*' If, then, the skin tends to be looseknit and thick, the hair is thick both on account of the large amount of earthy matter and on account of the size of the passages ; but if the skin tends to be compact, the hair is thin on account of the narrowness of the passages. Further, if the moisture is watery, it quickly dries off and the hair does not attain to any size, though it does if the moisture is greasy, because greasy matter does not readily dry off. Thus, generally speaking, thick-skinned animals have thick hair*; but it is not true that the thickest-skinned have thicker hair than (the others in the same categorj^), for the causes mentioned, an example being afforded by the pig tribe when compared A\-ith that of oxen, or \\ith the elephant and many other animals. For the same cause, too, our hair is thickest on the head : the skin there is thickest and situated over the largest amount of fluid,*^ and besides that it is verv loosely knit. And the reason why the hair is long [or short] is that the fluid which evaporates is not easily dried off. There are two causes which prevent it being easily dried off : one is its quantity, the other its quality. Thus, if there is a great deal of the fluid, and also if it is greasy, it does not easily dry off. And that is why the hair on our heads is the longest : the brain, being fluid and cold, pro\"ides fluid in large abundance.

Straight hair and curly hair" is due to the exhalation in it : if this exhalation is smoky,* being hot and dry it makes the hair curly ; for the hair gets bent because it is subjected to the impulse of two directional motions - the earthy constituent urges its way downwards, the hot constituent upwards ; and as the hair will easily bend on account of its weakness, it gets t\\-isted ; that is what curliness of the hair reallv is. Well, that is one cause that may be assigned for it : here is another. It may equally well be that, owing to its containing but little fluid as against a great deal of earthy matter, the hair gets dried by its environment and so contracts. Anything that is straight bends if its vapour is drawn off, and shrinks up like a hair burning on the fire, which would imply that the curliness of hair is a contraction due to lack of fluid caused by the heat of its environment. In favour of this is the fact that curlv hair is also harder than straight hair, and of course anything dry is hard. Animals that contain a great deal of fluid have straight hair, because in their hair the fluid advances in a continuous stream and not drop by drop. That is why the Scythians by the Black Sea and the Thracians have straight hair : both their constitution and the environing air are fluid (moist).

On the other hand, Ethiopians and people who Uve in hot regions have curly hair, because both their brain and the environing air are dry.

Some, however, of the thick-skinned animals have fine hair o^nng to the cause pre\"iously mentioned •* : the finer the passages are, the finer of necessity must the hairs be. That is why all sheep have fine hair, wool being just a very large number of hairs. There are some animals whose hair is soft, yet not so fine ; this is true of hares, for instance, in comparison with sheep. In such animals tie hair is on the surface of the skin ; and so it is not long, but turns out to be very much on a par with the scrapings that come off linen cloth, which have no length worth mentioning, but are soft and cannot be used for weaving. In cold climates sheep and human beings exhibit opposite " conditions " from each other : thus the Scythians have soft hair, but Sarmatian * sheep have hard hair, the reason for which is the same as it is in all \\ild animals. The cold congeals them and so dries them, and this makes them hard : in other words, the fluid evaporates at the same time as the heat is expelled, and both hair and skin become earthy and hard. Thus with wild animals the reason is that they live in the open air ; but in other cases it is the nature of their situation which is responsible. This is shown by what occurs in the case of the sea-urchins which are used as a remedy for cases of strangury. These creatures, although small in themselves, have long, hard spines, because the seawater they hve in is cold on account of its being so deep (60 fathoms or even more is the depth at which they are found). Their spines are long because the growth of the body is diverted to them, since, as the creatures possess but Httle heat, they cannot concoct the nourishment, and so contain a great deal of residue ; and it is out of residue that spines and hair and the like are formed. Their spines are hard and petrified on account of the cold and its congealing effect. And in the same way plants, too, are harder, and earthier, and more petrified if they grow where the aspect is northerly, or in a windy situation, than if they grow where the aspect is southerly, or in a sheltered spot. It is because they all get more chilled, and their fluid evaporates. Hardening, then, is brought about by both cold and heat : the effect of both is to cause the fluid to evaporate : it is evaporated by heat per se, but by cold per accidens - in the latter case the fluid accompanies the heat when it makes its exit, as there is no fluid ^^ithout its heat." There is this difference, however : cold causes compression as well as hardening, whereas heat lightens a thing's consistency. For the same cause hair, feathers and scales in the various animals respectively become harder as they get on in years : it is because their skins grow harder and thicker then, and that is due to their drying up, and old age or to " get on in years " is something earthy (as the similarity of the word with y earth, the old form of " earth," shows), and this is due to the fact that the heat is faiUng and with it the fluid.

Of all animals human beings are the ones which Baldness. go bald most noticeably ; but still baldness is a general and v^idespread condition. Thus, although some plants are evergreen, others shed their leaves, and birds which hibernate shed their feathers. Baldness, in those human beings whom it affects, is a comparable condition to these. Of course, a partial and gradual shedding of leaves takes place in all plants, and of feathers and hair in those animals that have them ; but it is when the shedding affects the whole of the hair, feathers, etc., at once that the condition is described by the terms already mentioned (baldness, moulting," etc.). The cause of this condition is a deficiency of hot fluid, the chief hot fluid being greasy fluid, and that is why greasy plants tend more to be evergreen than others. However, we shall have to deal with the cause of this condition so far as plants are concerned in another treatise, since in their case there are other contributory causes of it. Now in plants this condition occurs in winter : this seasonal change overrides in importance the change in the time of life. The same is true of the hibernating animals ; they too are in their nature less fluid and less hot than human beings. For human beings, however, it is the seasons of life which play the part of summer and winter ; and that is why no one goes bald before the time of sexual intercourse, and also why that is the time when those who are naturally prone to intercourse go bald. The reason is that the effect of sexual intercourse is to cool, as it is the excretion of some of the pure, natural heat, and the brain is by its nature the coldest part of the body ; thus, as we should expect, it is the first part to feel the effect : anything that is weak and poorly needs only a slight cause, a slight momentum, to make it react. So that if you reckon up (a) that the brain itself has very little heat, (h) that the skin surrounding it must of necessity have even less, and (c) that the hair, being the furthest off of the three, must have even less still, you •will expect persons who are plentiful in semen to go bald at about this time of life. And it is owing to the same cause that it is on the front part of the head only that human beings go bald, and that they are the only animals which do so at all ; i.e. , they go bald in front because the brain is there," and they alone do so, because they have by far the largest brain of all and the most fluid. Women do not go bald because their nature is similar to that of children : both are incapable of producing seminal secretion. Eunuchs, too, do not go bald, because of their transition into the female state, and the hair that comes at a later stage they fail to grow at all, or if they already have it, they lose it, except for the pubic hair : similarly, women do not have the later hair, though they do grow the pubic hair. This deformity constitutes a change from the male state to the female.

The reason why the hair does not grow again in cases of baldness, although hair and feathers grow again on hibernating animals and leaves on deciduous trees, is that in the case of the animals and trees the seasons are the turning-points of their lives more (than in the case of man), and so when there is a change of season, then they follow suit and grow or shed their feathers or hair or leaves. In man, however, the spring, summer, autumn and winter of his hfe are not seasons according to the calendar but seasons of his own age ; so that, as these do not go through the cycle of change, neither do the conditions which depend on them ; although the cause which controls the change of conditions is a similar one in his case too.

I think we have now discussed all the conditions that affect hair, except that of colour.

In the rest of the animals, the reason for the IV various colours of the hair, and for its being single- ^ain^ **' coloured or variegated, is the nature of the skin. In man, however, this reason operates only in the case of the greyness of the hair due to disease (as when the hair becomes white during leprosy), not that due to old age, and if the hair is white, the whiteness does not derive from the skin. The reason is that the hair grows out of the skin, and thus when the skin out of which it grows is diseased and white the hair is itself affected by disease, and disease of hair is grevness. On the other hand, the greyness which is due to age Greyness. is the result of weakness and deficiency of heat. Every age of life tends to gra\'itate into chilliness when the body's \igour declines, and especially when this happens in old age, since old age is cold and dry." We must bear in mind that the nourishment which reaches each part of the body is concocted by the heat in each part proper to it ; and if this heat is unable to do its work the part suffers damage, and deformity or disease is the result. A more detailed account of this cause will have to be given in the treatise Of Growth and Xutrition.^ In those persons

where the nature of the hair has but little heat and the fluid which enters it is unduly plentiful, the heat proper to the hair is unable to do its work and the hair is putrefied by the heat present in the en\ironment. All putrefaction, of course, is caused by heat, but not by the innate heat. This has been stated elsewhere." Water and earth and all such corporeal bodies are liable to putrefaction, and therefore the earthy vapour ** is liable to it as well : an example of this is what is called mould : mould is in fact the putrefaction of earthy vapour. So too the nourishment in the hair, being of this kind, putrefies if it does not get concocted, and what is called greyness results. It is white, because mould too is white. This is practically the only putrefied substance which is white, and the reason for that is that it contains a good deal of air : actually all earthy vapour is the equivalent '^ of thick air. In fact, mould is as it were the " opposite number " of hoar-frost, since if the vapour which rises up gets congealed, hoar-frost is the result ; if it gets putrefied, mould. And that is why both occur on the surface, because vapour is on the surface. So we see that the poets use a good metaphor in their comedies when they jokingly call white hairs the " mould " and " hoar-frost of age " : one of them is generically, the other specifically, the same as greyness : hoar-frost is the same generically (both being vapour), mould is the same specifically (both being putrefactions). Here is a sure sign that this is its character : there are many instances of people having grown grey hair as an aftermath of disease, but later on when they were restored to health dark hair took its place. The reason is that during a period of infirmity just as the wJiole body is afflicted by a deficiency of natural heat," so the parts, including even the verj' small ones, share in .this infirmity ; also, a great deal of residue is formed in the body and in its parts : hence the lack of concoction in the flesh produces grey hairs. But when health and strength is restored, people accomplish a change, as it might be old men renewing their youth, and, in consequence, the conditions also accomphsh a corresponding change. In fact, we might justifiably go so far as to describe disease as " adventitious old age " and old age as " natural disease " ; at any rate, some diseases produce the same effects as old age does.

The temples are the first part to go grey, and the reason is this. The back of the head, since it contains no brain,^ is empty of fluid. The bregma '" contains a great deal ; but a large volume of fluid does not easil}' putrefH". On the other hand, the hair on the temples has neither a small enough amount of fluid to secure concoction for it, nor a large enough amount for it to avoid putrefaction, as this region of the head is intermediate between the two extremes, and therefore stands outside both of these two conditions.

We have now given the reason for greyness so far as man is concerned.

The reason why this change does not noticeably V occur on account of age in the other animals is the same as the one already given in the case of baldness : their brain is small and (less) fluid,** thus the heat does not become completely unable to effect concoction. Of all the animals known to us, it is most marked in the horse, the reason being that in the horse the bone which surrounds the brain is, in proportion to the animal's size, thinner than that of any other animal. A proof of this is that a blow deUvered on this spot is fatal to a horse. Homer's lines " fit in with this too : Where on a horse's skull his hairs first grow. And where he suffers his most fell aild fetal blow.

Therefore, since the thinness of the bone makes it easy for the stream of fluid to flow to the hair at this place, and as the heat begins to fail on account of age, the result is that this hair goes grey. Reddish hair goes grey more quickly than black, as redness too is a sort of infirmity of the hair, and everything that is weak ages more quickly.^ Cranes, however, so it is alleged, go darker as they get older. If this allegation is true, the reason for this condition would be that the nature of their feathers is more fluid, and that as the birds grow old the fluid in their feathers is too plentiful to putrefy easily.*^ Here are proofs (a) that greyness is produced by putrefaction of some sort, and (b) that it is not, as some people imagine, a process of withering. Proof of (a). Hair that is protected by hats or other coverings goes grey more quickly, the reason being that the effect of the wind blowing is to prevent putrefaction, and the protection keeps off the wind. Also, it is an assistance if the hair is anointed with a mixture of oil and water. This is because, although the water cools it, the oil which is mixed with it prevents the hair from drying off quickly, water being easily dried off. (h) The following proves that greyness is not a form of withering, and that when hair goes white it is not due to withering, as it is in the case of grass. Some hairs are grey from the very beginning of their growth, and nothing begins its growth in a withered condition. In many instances, too, hairs go white at the tip ; this is because very little heat gets into parts which are at the extreme end and very thin.

In certain of the other animals white hairs make their appearance ; but this is natural and not due to any affection. The reason of the colours in these other animals is the skin : thus, if they are white, the skin is white ; if black, the skin is black ; if piebald, made up of a mixture of colour, the skin is, we find, white in some places and black in others. In the case of human beings, however, the skin has nothing whatever to do with it, for even people with white skin have intensely black hair. The reason for this is that, for his size, man has the thinnest skin of all animals, and on that account it has no power at all to effect any change in the hair ; instead of that, the skin, by reason of its own weakness, changes its colour itself, and also is darkened by the action of the sun and the wind, while the hair undergoes no simultaneous change at all. With the other animals, the skin, on account of its thickness, possesses the character of the region in which the animal hves ; and that is why the hair changes in accordance with

creature suffers some distortion during the process of its formation, for, since the beginning of things that pass through such a process is on a small scale, they are small at that time, and what is small can easily be given a different turn and spoilt." The ones that change most are those which, though whole-coloured by nature, belong to a class which is many-coloured. This is due to the varieties of water involved. Hot water makes the hair white, cold water makes it dark, which is exactly what happens in the case of plants. The reason is that the hot ones contain more pneuma than they do water, and it is the air shining through that causes the whiteness, just as it makes froth white. Therefore, just as there is a difference between skins that are white by nature and those that are white o\\'ing to some affection, so there is a difference between the whiteness of hair which is due to nature and that which is due to disease or age - and the difference lies in the fact that the cause is different. In the former case, the whiteness is caused by the natural heat, in the latter, by extraneous heat."^ It is the vaporous air shut up inside them which produces whiteness in all things ; and that, too, is why those animals which are not singlecoloured are all whiter under the bellv than elsewhere. Thus too practically all white animals are hotter and tastier for the same cause : their good flavour is produced by concoction, and concoction is produced by heat. And the same cause holds also in the -case of those animals which, being singlecoloured, are either dark or white ; since it is heat and cold which are the cause of the nature of the skin and of the hair, each of the parts of the body having its own proper heat.^

Further, the tongues of animals differ : those of the simple-coloured " animals, those of the variegated ones, and those of the ones which, though simplecoloured yet differ among themselves (as, e.g., dark and white)- the tongues of these are all different. The reason is that which has been stated already, viz., that the skins of variegated animals are variegated, the skins of white-haired ones are white and of dark ones dark. The tongue we should look upon as being, as it were, one of the external parts of the body, comparable, e.g., ^^ith the hand or foot, disregardinof the fact that it is being covered in bv the mouth. So that, as the skin of the variegated animals is not single-coloured, this will be the reason responsible for the skin on the tongue as well.

Some birds and some >\-ild quadrupeds change their Seasonal colour according to the seasons of the year. The c^fo^ "'^ reason is that, just as human beings change according to their age, so these change according to the seasons, because this constitutes a greater difference so far as they are concerned than the change according to age.

Speaking generally, the more omnivorous animals Effect of are more variegated, as we should expect (for in- co^om! stance, bees are more single-coloured than hornets and wasps), for of course if the various sorts of nourishment they take are the causes of the change, we shall expect to find that variegated kinds of nourishment make the movements which the nourishment undergoes and the residues which result from it more variegated, and it is out of the residues that hair, feathers, and skin are formed.

This concludes our account of the various colours, and the various kinds of hair.

deep " voice, others a high-pitched voice, others a well-pitched voice, suitably proportionate between the two extremes ; some, too, have big voices, others small ones ; also they differ in respect of being smooth, or rough, flexible and inflexible. So we must consider what are the causes to which each of these is due. With regard to the pitch, the same cause is to be held responsible as that which controls the change which they undergo in passing from youth to age. All animals when younger have a higher voice, except calves, which have a deeper one. The same occurs as between male and female as well : in all animals (except cattle) the female has a higher voice than the male, and this is especially noticeable in human beings, for Nature has given them this faculty in an exceptional degree because they alone among the animals use the voice for rational speech, of which the voice is the " material." In cattle the reverse obtains : cows have a deeper voice than bulls. We have explained partly in the treatise Of Sensation.^ partly in that Of the SoiilS for what purpose animals have a voice, and what " voice " is, and generally what sound is. But since deepness of pitch consists in the movement being slow, and height of pitch in its being fast, the question is whether the speed is caused by that which initiates or that which experiences the movement, and this is somewhat puzzling. Some people hold that the movement of a large voliune is slow and that of a small volume fast, and that this is the cause why some animals have deep voices and others high ones. Up to a point this statement is satisfactory^ but not completely so. It is, of course, correct to say that,

in general, deepness depends upon a certain size of that which is set in movement ; but if the statement were wholly true, it would not be easy to utter a noise simultaneously small and deep, nor, similarly, large and high. Further, a deep voice seems to be the mark of a nobler nature, and in melodies, too, that which is deep-pitched is better than the highpitched, since deepness is a form of superiority, and it is in superiority that betterness resides. In fact, however, deep and high pitch of the voice is a different matter from largeness and smallness of the voice, for some animals which have high-pitched voices are large-voiced, and in the same way some which have deep-pitched voices are small-voiced ; and the same appUes to the intermediate pitch between the two. And what other means is there for defining largeness and smallness of voice apart from the volume of that which is set in movement ? So then, if high and deep pitch are to be distinguished according to the definition mentioned above, the result will be that any animal which has a deep voice will also have a large one, and any which has a high voice will also have a small one. And this is not true. The reason is that the terms " large," " small," and " large amount," " small amount " are sometimes used in an absolute sense, sometimes relatively to each other. If an animal has a large voice, this is because the amount of that which is set in movement is large absolutely, if small, the amount is small absolutely ; whereas high pitch and low pitch are due to the amounts " involved being large and small relatively to each other. Thus, if that which is set moving exceeds the strength of that which sets it moving, then that which is propelled is bound to go slowly ; if it is exceeded, it

Will travel quickly. So then, the movement which a strong agent produces is sometimes slow (i.e., when, in virtue of its strength, it is mo\'ing alarge amount), and sometimes fast {i.e., when the agent has the upper hand). In accordance with the same line of argument, in some cases the movement which a weak agent produces is slow (i.e., when the agent is setting in movement an amount which is too large for its strength), in other cases the movement is fast (i.e., when o\^ing to the agent's weakness the amount which it sets mo\-ing is small).

Such, then, are the causes to which these contrarieties are due. We have shown (a) why neither voung, nor old, nor male nor female animals all have high-pitched voices or all have deep voices ; (h) why sick and healthy alike speak in a high-pitched voice ; and (c) why, as men reach old age, the pitch of "their voice rises, although old age is the opposite of youth.

On account of their debilit}-, most animals when young, and most females, set but a small amount of air in movement and therefore have high-pitched voices, because a small amount is propelled at a fast speed, and where the voice is concerned fast means high. In calves, however, owing to their age, and in cows, owing to the nature of femininity, the part by means of which they set (the air) in movement is not strong, and as they set a large amount of it in movement, they have deep voices, for a large amount of air travels slowly, and anything that travels slowly is heavy (deep).* A large amount (of air) is set in movement by these animals, but only a small amount by the others, the reason being that in the former the vessel through which their breath first travels has a large opening and is therefore forced to set a large

amount of air in movement, whereas in the latter the breath is under better control. In every animal, as age advances, this part which sets (the air) in movement becomes stronger, so that a change-over" to the opposite is effected : high-pitched voices become deeper than they were, and deep-pitched ones higher. That is why bulls have higher-pitched voices than calves and cows. Now in all animals their strength lies in their sinews, and that actually is why animals in their prime are stronger than the others : young ones are less well articulated and less well supplied with sinews, and furthermore, their sinews have not yet become taut, whereas in ones that are aged their tautness has slackened off. Hence both young and old are weak and powerless so far as producing movement is concerned. Bulls however, being especially sinewy, have especially sinewv hearts ; hence this part, by which they set the breath in movement, is taut, just Uke a sinewy string stretched tight. Bull's hearts are shown to be sinewy by the fact that in some of them a bone * actually occurs, and bones seek the nature of sinew. <^ All animals when castrated change over to the female state, and as their sinewv* strength is slackened at its source they emit a voice similar to that of females. This slackening may be illustrated in the following way. It is as though you were to stretch a cord and make it taut by hanging some weight on to it, just as women do who weave at the loom ; they stretch the warp by hanging stone weights ^ on to it.

This is the way in which the testes are attached to the seminal passages, which in their turn are attached to the blood-vessel which has its starting-point at the heart near the part which sets the voice in movement." And so, as the seminal passages undergo a change at the approach of the age when they can secrete semen, this part undergoes a simultaneous change. And as this changes, so too does the voice - to a greater extent in males, but the same happens with females as well, though the change there is less obvious ; and one result of this is that, as we say, the voice " is breaking " ^ during the time that it is uneven. After that, it settles down into the deep or high pitch belonging to the age of Hfe which is to succeed. If the testes are removed, the tautness of the passages is slackened, just as when the weight is removed from the cord or from the warp ; and as this slackens, the source (or principle) which sets the voice in movement is correspondingly loosened. This then is the cause on account of which castrated animals change over to the female condition both as regards the voice and the rest of their form : it is because the principle from which the tautness of the body is derived is slackened. The reason is not, as some people suppose, that the testes themselves are a ganglion of many principles. No ; small alterations are the causes of big ones, not in \'irtue of themselves, but when it happens that a principle changes at the sarne time. The principles, though small in size, are great in power : that is what it means to be a principle - something which is itself a cause of many things, while there is nothing more ultimate which is the cause of it.

The heat and cold of their place of habitation is another factor contributing to the fact that the natural construction of some animals is such that they have deep voices, and of others, that they have high voices. Breath that is hot produces deepness (heaviness) of voice, owing to its thickness ; breath that is cold produces the opposite result, owing to its thinness. This is plain in the case of musical pipes as well : people who blow comparatively hot breath into the pipe - i.e., if they breathe it out as though they were saying " Ah I " - play a deeper note. The reason for roughness and smoothness of voice and all unevenness of that sort is that the part or organ through which the voice travels is rough, or smooth, or, to put it generally, is even or uneven. This is apparent when there is any fluid about in the trachea, or if there is any roughness due to an affection : in such circumstances the voice becomes uneven too. FlexibiUty depends upon whether the organ is soft or hard, since anything that is soft can be controlled and made to assume all sorts of shapes, whereas anything hard cannot. Thus this organ if it is soft can utter a small sound or a large one, and therefore a high one or a deep one as wejl, because it controls the breath easily, as it easily becomes large or small itself. Hardness on the other hand cannot (so) be controlled.

This will be a sufficient account of those points concerning the voice which we have not already settled in the treatises Of Sensation and Of the Soul.

We have already said," on the subject of the VIII teeth, that their existence is not for one purpose Teeth. only, nor do they exist for the same purpose in all animals : some have teeth on account of nourishment, some for self-defence and (some) for rational speech. But why are the front teeth formed first and the molars afterwards ? And why are the molars not shed, whereas the front teeth are, and ^row again ? We must take it to be appropriate to examine the cause of these things in a treatise on Generation.

Now Democritus has treated of these matters, but his treatment is not correct, because he assigns a cause to apply generally although he has not undertaken an exhaustive investigation of the facts. He says that the reason why animals shed their teeth is that they are formed prematurely, since it is when animals are in their prime or thereabouts that they grow their teeth according to nature. Suckling is the cause he names for their being formed prematurely. Still, the pig suckles, yet does not shed its teeth " ; and so do all the animals with sharp interfitting teeth,* but some of them (e.g., the lion '^) do not shed any teeth except the canine ones. Democritus, then, made this mistake because he made a general statement without investigating the facts in all cases ; but this is precisely what we ought to do, because whenever anyone makes a general statement it must apply to all cases. Now the assumption we make - and it is an assumption founded upon what we observe - is that Nature neither defaults nor does anything idly in respect of the things that are possible in every case ; and further, if an animal is going to get any nourishment after the period of its suckling is over, it must of necessity possess instruments with which to deal with its nourishment. So that if this took place, as Democritus says, about the time of maturity, Nature would be defaulting in one of the things which it is possible for her to do, and we should have Nature

working contrary to Nature " (because he says that the formation of the teeth is brought about by force, and " by force " means " contrary to Nature "). So then it is apparent, both from these considerations and others hke them, that this view is untrue.

The teeth of which we are speaking are formed earher than the flat teeth (1) because the work they have to perform comes earher : breaking up (which is the purpose of these teeth) comes before grinding (which is the business of the flat ones) ; (2) because a smaller thing naturally forms more quickly than a larger one, even if they both start off together, and these teeth are smaller in size than the molars, because the jawbone at that point is flat, whereas it is narrow by the mouth ; and, of necessity, a larger amount of nourishment will flow out from the larger part, and a smaller amount from the narrower.* Suckling, in itself, contributes nothing to the formation of the teeth, though the warmth of the milk makes them come through more quickly. A proof of this is that* within the actual class of those which suckle, those young ones which get hotter milk grow their teeth quicker, because that which is hot tends to promote growth.

After having been formed, these teeth are shed (o) for the sake of the better, the reason being that anything sharp quickly gets blunted, and so a fresh relay of teeth is needed to carry on the work. (The flat ones, on the other hand, cannot get blunted ; they only get worn down in the course of time by friction.) They are shed also (b) as a result of necessity, because, whereas the roots of the grinders are situated in the wide part of the jaw and upon good strong bone, those of the front teeth are in a thin part, and in consequence the teeth are weak and can easily be removed. They grow a second time, because thev are shed while the bone is still growing and while the age for growing teeth is still going on. A proof of this is that even the flat teeth take a long time growing : the last of them are cut at about twenty years of age ; in fact, some people have been quite aged before their last teeth finished growing. The reason for this is that there is a great deal of nourishment in the wide part of the bones. The front part, however, quickly reaches its completion owing to its thinness, and no residue finds a place in it ; instead of that, the nourishment is consumed to supply that part's own growth.

Democritus, however, omitted to mention the Necessity Final Cause," and so all the things which Nature p^naic^aus employs he refers to necessity. It is of course true that they are determined by necessity, but at the same time they are for the sake of some purpose, some Final Cause, and for the sake of that which is better in each case.* And so there is nothing to prevent the teeth being formed and being shed in the way he says "^ ; but it is not on that account that it happens, but on account of the Final Cause, the End ; those other factors are causes' qua causing movement, qua instruments, and qua material, since in fact it is probable that Nature makes the majority of her productions by means of pneuma ^ used as an instrument. Pneuma serves many uses in the things constructed by Nature, just as certain objects do in the arts and crafts, e.g., the hammer and an\-il of the smith. But to allege that the causes are of the necessary type is on a par with supposing that when water has been drawn off from a dropsical patient the reason for which it has been done is the lancet, and not the patient's health, ybr the sake of jrhich the lancet made the incision.

We have now dealt with the subject of the teeth, and we have stated why some of them are shed and grow a second time and why some of them do not, and generally, to what cause their being formed is due. We have also dealt \\-ith the other conditions which affect the parts of the body, conditions which occur not for the sake of any Final Cause but of necessity and on account of the Motive Cause.

Additional Notes on the Text

I add here four textual annotations for which there was no room in the body of the work.

I. 719 a 2 if. The mss. and editions have various readings, and several proposals have been made for emendation, Bekker has : t6v avrov Tpoirov to. irXeiOTa yiyveTai ovnep ev Tols opvicriv (opvidiois SYZ)' Kara^aivei yap Karo), Kal . . .

Z : ... yiyverai ovnep . . . Kal Kara^aivet KO-TU) . . .

P : ... yiyv6(j.evov ovnep . . . KaTa^alvet koltco . . .

S : ... yiyveTai oiOTxep . . . Kara^aivet. KaTw . . .

(Hence Y must be the authority for yap.) Aldus : ylyverai ovnep . . . opvidioLS Kara^aivei KaTco . . .

A.-W. coni. : (ij TeXelcoais} ylverai ovnep ev roZs opviaiv (to aia) Kara^aivet kuto) . . . Susemihl coni. : . . . opviaiv (jj reXeiuiois' ra S' (ha) Kara^aivet KaTlO.

If loss of this sort is likely, which I doubt, a more probable emendation would be Kara^aivei yap Karw (ja a>d), koI . . . But I suspect that the corruption is more serious, for Scot reads : et similiter multis ovis avium ; <.et quedam animalia ovant interius, et exit ab eis animal parvum, ; et cum pervenit tempus partus> descendunt K.ovay ad partem inferiorem, apud iuncturas et exit ab eis animal sicut accidit animalibus generantibus animalia ex prima creatione. The Greek original of the words in brackets has disappeared from our text.

II. 738 a 8 ff. I suspect that the original reading here was TOi? â– nepiTTtufiaai rols t' axprioroi? {koI toTs ;fp7jCTt/Liots), and that the rest of our present text is part of a gloss, for ttj Te . . . vypa. cannot be construed, and the reference to blood seems to consider blood as a " residue," which is incorrect. If my suggestion is right, the gloss will have ousted the reference to useful residues from our text, and the reference to useless ones from Scot's ultimate original, for Scot reads omnia ista habent membra recipiencia superfluitatem qva indigent (his regular equivalent for xp^ciMoj) sicut sanguis qui habet locum in venis ; ergo ipse vadit in ea sicut in vasa. Clearly, too, Scot incorporates more of the latter part of the gloss than the Greek text does, and the reference to vasa ( = dyyera) leads me to think that the gloss was founded on a misunderstanding of the passage at P. A. 650 a 33 (q.v.). The blood-vessels are often described as ayyela in P. A. ; c/. G.A. 740 a 23.

II. 746 a 33. Here Bitterauf, following the suggestion of Bussemaker, proposes to insert </cai Ococuv} after Kal Xvkwv on the strength of William's and Scot's versions. The latter reads in canibus et vulpihus et lupis et in genere quod dicitur grece comez (Buss, and Btf. give comex). This is supported by the fact that at 774 b 17 Scot translates kvojv Xvkos dws canis et lupus et animal quod dicitur grece noz. (Such variation in the spelling of proper and other unusual names is not infrequent in Scot.) At 743 a 9 Oojs is not represented in Scot's version.

(According to A.-W., dots, usually translated "jackal," is most probably the civet or genet : see D. \V. Thompson, H.A. 580 a 29, n.) V. 781 a 10 ol yap nopoi . . . 781 b 5 avyL^aivovmv. The main arguments against this passage being an original and genuine part of the text may be stated as follows : (1) The introductory yap introduces no real explanation or expansion of the preceding statement. The passage is in fact completely extraneous to the argument.

(2) The reference to De sensu at 781 a 21 is incorrect, as A.-W. point out. There is no such clear statement in De sensu ; at 439 a 1 the atadrj-rripiov of touch and taste is said to be npos TTJ KapSia, but nothing is said to suggest that sight and smell have any further connexion beyond their connexion with the brain. At P. A. 656 a 29, on the other hand, there is a more exact reference to De sensu : " The correct view, that the dpxT] of the senses is the region around the heart, has already been defined in the treatise 0/ Sensation, where also I show why it is that two of the senses, touch and taste, are evidently {(f>av€pu)s) connected to the heart." Shortly before (656 a 20 ff.) Aristotle has stated that the brain is not the cause of any of the sensations ; it is dvaiadrjrog.

(3) The passage is concerned exclusively with that part of the mechanism of hearing which is internal, not with the superficial sense-organ, whereas the reason given for accuracy of hearing and smelling is concerned only with the superficial sense-organ (just as the similar argument for sight, which is referred to, is concerned only with the eye itself and the skin on it).

(4) The passage has nothing whatever to say about smell.

(5) It concludes with a mere repetition of 781 a 18-20, to the effect that accuracy depends upon the puritj' of the organ and its membrane, ignoring the whole of the intervening discussion about the internal mechanism.

(6) The reference to a place where the connate pneunia causes " in some " pulsation and " in others " respiration and inspiration is, as Platt points out, meaningless, for no animal respires unless it has a heart.

The inference would appear to be that the passage, though probably of Aristotelian origin, has been corrupted, and that, so far as Book V is concerned, it began as a marginal annotation, intended to supply an account of the inner mechanism of sensation, etc., which would supplement the account of the mechanism of the superficial sense-organs of hearing and smell which no doubt originally stood here in the text. No such account, however, is there now ; and it seems reasonable to suppose that it has been ousted and supplanted by the passage which now stands there.

To understand the background of the passage, the reader may find it useful to refer to the account of Aristotle's theory of hearing in App. B §§ 29 ff., which I have compiled from various passages here and elsewhere in his works. I have suggested in the critical note some corrections, based on Scot's Latin version, which may help to bring the text into agreement with Aristotle's doctrine as ascertained from these other passages.

For the sake of completeness, I give the remainder of Scot's translation between the two passages already quoted in the app. cr'it. : \et\ propter hoc addiscuntur res per (v.l. propter) sensum auditus, quoniam sicut sermo intrat per sensum auditus, ita exit per linguam [et] per motum vocis. manifestuni est ergo quod homo dicit (v.l. discit) quod audit, et cum homo gannit debilitatur auditus, quoniam principium instrumenti sensus istius est positum super ^nembrum in quo est spiritus, et movetur cum eo quando spiritus movebitur instrumento in quo est. et hoc accidens accidit temporibus humide complexionis.

The passage is discussed at considerable length by F. Susemihl, Rhein. Mus. XL (1885), 583 ff.

Additional Note for II. 741 b 2. III. 762 b 24 fF.

The first modern work on the breeding migration of the Thn European eel {AnguUla milgaris) is that of Grassi " and Common Calandruccio, who, following some previous work on ^°'the reproductive organs, made observations of eels in the Mediterranean, and showed that Leptocephalus, already known and described as a different animal, was the larval form of the eel. The whole subject has been fully worked out by Schmidt * in recent years. The facts are these. During the time when eels live in fresh water, their reproductive organs do not reach maturity, as Aristotle pointed out ; but after a number of years, which may vary from five to twenty, the body takes on a metallic sheen (" silver eels ") and the fish set out on their migration to their breeding-places in the deep waters between the West Indies and Bermudas. The eggs float in the sea, and the larvae are carried by the ocean currents eastwards across the Atlantic : upon arrival at the Continental shelf two and a half years later they metamorphose into elvers, and these then move up into the estuaries and rivers of Europe, sometimes passing over damp grass to isolated pools. During the period of growth which follows, they are yellowish and greenish in colour (" yellow eels "). The old eels never return to fresh waters. The story (mentioned by Aristotle) of the development of eels out of horsehair worms was current until recent times.

Additional Note for III. 757 a 2 ff.

Aristotle discusses the hyena both here and at H.A. VI. The Hyena. 579 b 15 ff.

An important piece of research on the spotted hyena recently carried out in Tanganyika Territory by L. Harrison Matthews ' has established that externally the female of the spotted hyena closely resembles the male : it has a peniform clitoris, similar in form and position to the penis of the male, and scrotal pouches closely simulating those of the male. Indeed the male and non-parous female arc indistinguishable externally. Matthews points out that Aristotle did not distinguish between spotted and striped hyenas : the legend " relates to the spotted hyena, but Aristotle's refutation of it to the striped, the genital anatomy of which he correctly describes " (Matthews refers to the description in H.A.). Of 103 specimens collected by Matthews, 63 were males ; this is a lower percentage than that given by the hunter with whom Aristotle discussed the subject : he found ten out of eleven were males, but these may have been striped hyenas.

  • G. B. Grassi, Proc. Roy. Soc. LX (1897). 260-271.
  • J. Schmidt (of Copenhagen), The Breeding Places of the Eel, Phil. Trans. Roy. Soc. (B) CCXI (1922). 179-208; see also id.. Nature, CXI (1923). 51-54, CXIII (1924), 12; and W. Heape, Emiffration, Migration, and Somadism, 1931.
  • Reproduction in the Spotted Hyena ((^rocuta crocuta), in Phil. Trans. Roy. Soc. (B) CCXXX (1939), 1-78.

tha closely resembles the male : it has a peniform clitoris, similar in form and position to the penis of the male, and scrotal pouches closely simulating those of the male. Indeed the male and non-parous female arc indistinguishable externally. Matthews points out that Aristotle did not distinguish between spotted and striped hyenas : the legend " relates to the spotted hyena, but Aristotle's refutation of it to the striped, the genital anatomy of which he correctly describes " (Matthews refers to the description in H.A.). Of 103 specimens collected by Matthews, 63 were males ; this is a lower percentage than that given by the hunter with whom Aristotle discussed the subject : he found ten out of eleven were males, but these may have been striped hyenas.

Appendix A


It will be seen that the terminology of the ttco passages above mentioned reappears in the following account, much of which is taken verbatim from the several passages to which reference is given. I have not thought it necessary to draw attention to all the parallels, as these will be obvious to the reader icho has the passages of G.A. before him.

(1) Met. A 1069 a 30 ff. There are three kinds of ovala : Three kinds f(«) eternal (atStos) ; of being.

(I) sensible (oiff^Tp-ij) - (6) perishable {(fdapros), e.g., [ animals and plants ; (2) immutable {aKivrp-os). Immutable ovaia is the ovala of the unmoved mover (see below, § 3) ; sensible and eternal ovala belongs to the " heaven " and the heavenly bodies (the stars and planets, including the Sun and Moon) ; sensible and perishable ovala belongs to the things of the sublunary world (Earth, Air, etc., and the organisms made out of them, animals, plants, etc.)." (2) Dc caelo, e.g., 268-269, 289 a, 300 a 20 ff., etc. There are Five five natural substances which compose the physical elements, universe : Aither, whose nature it is to move eternally in a circle ; this is the substance out of which the whole of the L'pper Cosmos is made, viz., the " first heaven " (the outermost shell or sphere) in which the stars are a See also App. A § 18.



Unmoved Mover and the ^opd of the First Heaven.

fixed, and also the planetary "heavens" together with the planets themselves which they carry ; Fire, Air, Water and Earth, whose natural movement is rectilinear {e.ff.. Air moves naturally outwards from the centre. Earth moves naturally towa,rds the • centre ; hence they would if left to themselves <• arrange themselves in concentric strata, with Fire outermost, next to the innermost " heaven " ; after that Air, then Water, and Earth at the centre). These are the substances out of which all the Lower Cosmos, the subhmary Avorld, is composed. The (3) Met. A 1072 a, b. The ultimate source of all movement is the Unmoved Mover, which is pure, self-thinking thought, or God ; and since the " actuality " of thought is life, we can say that ^wij Kai alutv awexv^ ko-I' oiibios vndpxeiTO) dew. This " first principle " causes movement without itself being in movement ; it is therein analogous to objects of desire or of thought, which Kivel oi5 kivovueva ^ ; in fact, it Kivel cos epcofievov (it causes movement by being an object of love)."^ Upon this first principle the Heaven and Nature depend. What it first sets in movement is the irpcorov Kivovfievov, the prhnum mobile, viz., the "first heaven " or outermost sphere ; and since this movement is an unceasing movement, so the first heaven will be at'Stoy. This movement, then, is one and eternal ; it is simple <f)opd, simple uniform circular movement. Movement (4) All other things beside the Unmoved Mover which proin the duce movement do so in virtue of being themselves Cosmos^ in movement (/civoiJ/xeva rS-XXa Kivel). Thus the "first heaven " communicates movement to the inner " heavens," the whole system of concentric spheres, which are in contact with each other ; and the movements of these, although still continuous and eternal, are no longer uniform, because they are the resultants of more revolutions than one."* « As in fact they are not (see § 12 ; cf. § 9). Nor, according to Aristotle, are the elements occupying their "proper" places when acting as the components of living bodies (Be caelo II. 288 b 17 ff.).

b Cf. App. B § 1.

' Cf. Dante, Paradiso, vers, ult., I' amor cfie move il sole e I' altre stelle.

<i It is not necessary here to give details of the system of spheres as worked out by Aristotle, based on the mathematical theories of Eudoxus and Callippus.


APPENDIX A (5) In the " region about the centre," i.e., the Lower Cosmos Movement or sublunary world, there is no circular movement at all '° the as such. The form in which movement is foimd here is p°*^ in the " movements," i.e., transformations of the four sublunary " simple " bodies. Fire, Air, Water, Earth, and in the " movements " of living creatures, animals and plants, viz., yeveais and tf>dopd, " alteration," growth and diminution." *' Movement " is mediated to the things in the Lower Cosmos through the heavenly bodies, chiefly the Sun, as is stated at the end of G.A. IV.

(6) Meteor. I. 339 a 38. We should regard Fire, Earth, etc.. The . as the " material " causes of phenomena in the sublunary "Causes world ; but the cause in the sense of the origin of move- t^e Lower" ment (the " motive " cause) is to be found in the dynamis Cosmos, of the eternally moving bodies.* (7) Ibid. 340 b, 341 a. The " first element " {alias the The " fifth element," viz., aither ; see 737 a 1, n.) and the heavenly bodies in it revolve in a circle, and as they do so, that ^^v**^ ' portion of the Lower Cosmos which is next to the aither gets inflamed and produces heat. Thus, although not made of Fire, and although not themselves hot, the heavenly bodies produce heat by their mere movement. Aristotle explains this more fully at De caelo II. 2S9 a 29, when he says that the heat and light which proceed from them are produced by the friction set up in the Air by their (f)opd {cf. § 9 Jin. below). The Sun, which is considered to be the hottest of them all, is really white (XevKos), not fiery in colour. The Sun's tj>opd is sufficient to produce warmth and heat : it is fast enough and near enough, whereas the (JMpd of the stars though fast is distant, and the Moon's though near is slow (cf. De caelo IL 289 a 20-34).

(8) Ibid. 346 b, 359 b. Rain and winds are explained as Rain and being caused by the Sun's approaching and receding in winds, its (l>opd. When it approaches it draws up the moist exhalation ; when it retires this vapour cools and congeals again into water ; hence there is more rain during winter and during the night. It also draws up the dry exhalation, and this is the substance which makes the winds.

(9) It is pointed out in De caelo II. 286 b 2 that in order to Function of the other « See Introd. §§ 47 ff., ict'i^o-cs. * Quoted in Greek at 777 b 31, n.


APPENDIX A heavenly account for the transformations of the four " elements " i^opai in Fire Air Water Earth, i.e., for the yeveais of them out causing of one another, some additional (f>opa. or <^opat beside that (a) yevt<rii ; pf |.jjg 'I Whole " (or the npcoTov Kivovfievov) is required : if this were the only <l>opd, no transformation would take place and the four elements would be static.

And with regard to the yeveais of living things, Aristotle describes in other treatises more strikingly and in fuller detail than he does in G.A. the important part played by these other <f>opai (i.e., those of the heavenly bodies). Thus in Phys. II. 194 b 13 we read dvdpcoTTos dvOpcDTTov yevva Kai ijAioj"; and at Met. A 1071 a ISff. the " causes " of a man are listed as (a) the " elements," viz., (i) his matter (Fire and Earth), and (ii) his own form (rStov ethos) ; also (h) something external, viz., his father ; and besides these (c) the Sim and the circle of the ecliptic (o Xo^os kvkXos) - and these last stand to him neither as matter, nor as form, nor as privation, nor as being identical with him in form, but as Kivovvra, i.e., " efficient " or " motive " causes [cf. §§ 5 and 6 above). Cf. also G.A. II. 737 a 3 : the heat of the Sun and the heat of animals as contained in semen is able to cause generation, whereas Fire cannot. (b) ycVems (10) The whole question of yeveais and <f>dopd is more fully and ^flopo. discussed at the end of the treatise G. 4" C. (II. chh. 10 and 11), where the meaning of the statements about the Sun and the ecliptic is explained. Here Aristotle states that yeveais is continuous because the circular revolution of the " first heaven " is eternal (17 Kara, ttjv (fiopdv Kivrjais is dt'Sios) ; and this <l>opa. produces yeveais by bringing to yew-qriKov (the generative agent, viz., the Sun) nearer and by taking it further away. This <j>opd however is a single movement (as we saw above, § 3), and therefore will only explain yeveais ; it will not also ex « This would not, however, have sounded so strange to a Greek ; cf. G.A. 716 a 17 ovpavov Si Kai rfKiOv ... is yivvuivras koX rrarepa^ npoir ayopfvovmi'. - It is a Statement which caught the fancy of the Middle Ages, and is quoted by Dante (from the Latin translation of Physics II) in his JDe monarchia I. 9 iriit. ; cf. Paradiso XXII. 116 quegli ch' i padre d' ogni mortal vita.

Aristotle regularlv takes these two as tlie elements par excellence, standing for all four (see De caelo III. 298 a 29, 298 b 8) - because Fire " has not heaviness " and Earth " has not lightness " (IV. 311 b 27). Cf. App. B §§ 20, 22, 23.


APPENDIX A plain <f>6opd. Thus yev€ms'and-<f>6opd is to be explained not as being due to the primary (f>opd [i.e., the <j)opd of the " first heaven "), but as being due to the (f>opd Kara. Tov Xo^ov kvkXov - the movement along the circle of the ecliptic, which is tilted. This, like the other, pKJssesses continuity ; but also it is double, not single. Thus we may say that the continuity is caused by the <f>opd of "the Whole*' {i.e., the "first heaven"; the primary <f>opd), while the alternation is produced by the inclination of the ecliptic, which makes the Sun alternately approach and retreat. \\'hen the Sun approaches it will cause yeVeais, when it retreats it will cause <f>dopd.

(11) Now in consequence of this, natural (Kara (f)vai,v) yeveais TtVecrts and (f>$opd occupy equal times for their accomplishment. ^^^ <i>6oiM Hence both the times and the lives of all several things ^y have a " number " and by that number they are delimited "periods." . . .and every life and time is measured by a period . ..: for some, this period is the year ; for others, the period, ichich is the measure, is greater, for others, smaller (8i6 Kcu 01 xpovoi Kox ol Pioi eKdoTOiv dpidnov exovat Kal tovtw hiopit,ovTai. . . . /cat nds jSt'oj Kal XP^vos fierpeirai â– jrepiohip . . . • TOi? p.kv ydp 6 iviavTOs, tols 8e pxi^(i)v, Tots Se eXd-rrcov -q Treplobog eori to fiSTpov). He then repeats that natural yeveais and <f>dopd occupy an equal time : but, he adds, in point of fact things often <^et'pcTat in a shorter time than this ; for since matter is uneven (dvcu/xoAo? ; cf. his statement in G.A. W fin. about its " indeterminateness " ), the yeveaeis of things are uneven too, some being quicker and some slower than they should be : and as a result of this the (f>dopd of other things is affected, l>ecause the yevems of one set of things is the <t>dopd of another. (See also App. B §§ 7-11.) (12) T€V€ms-and-(f>dopd is continuous, and shall never fail. Continuous The reason is that Nature always strives after to ^eXriov, ye»«a-t5 a and being is better than not-being ; but since being ^"Jl*^ al**^ cannot be possessed by all things because they are too being.

far away from the dpx^ ('.«'•, from God, the Unmoved Mover), God " filled in '" the Whole in the manner that remained open, viz., by making yeVewi? continuous ; that was the way to ensure that as far as possible there should be an unbroken chain of " being " throughout . the universe, for the next best thing to " being " is that 571

APPENDIX A yeveais should be continually going on (to yiveadai det rT]v yeveaiv) ; and the cause of this is the circular <f>opd ; for this is the only continuous form of movement. Hence also the things which get transformed into each other (viz., the " simple bodies," such as Water, Air, Fire) imitate the circular ^opa : Water is transformed into Air, Air into Fire, Fire into Water, and we say that their yheais has come i-ound a full " circle." (So, too, rectilinear (f>opd is continuous in virtue of its imitating circular <f>opa..) And this also provides a solution of the problem, Why is it that the " simple bodies," in spite of their natural tendency to make each for its own proper place in the vmiverse, have not during the enormous stretches of time which have passed become separated out each into its own proper place, into concentric layers (see § 2) ? The reason is that they are continually lieing transformed to and fro one into the other, and the cause of their transformations is the <f>opd - i.e., the double <f>opd. Measure- (13) Phys. IV. 219 b 3 ff. We cognize movement by means ment of of some body which is in movement ; so too we cognize "'" ' ^opd by means of some body which is 4>€p6p.evov : that ment of ^^ ^^^^^ ^'^ cognize the " before-and-after " factor in time. movement, for it is the " now " {I.e., the moment at which the body is observed to be at some particular point in its course) which is " most cognizable." And just as (l>opd and the (jjepofievov are thus closely allied, so too are the dpidp.6s " of the (j)opd and the dpi9fi6s of the (f>€p6iJ.evov. Now time is the dpidftos of the (f>opd. We see then that time is not movement, but it is " the aspect of movement whereby movement has an dpi9/xo?," i.e., the aspect of movement whereby movement can be numerated or counted (^ dpidp.6v exei -fj Kivrjacs) : time is that wiiich is counted, not that by which we count (to dpidixovp-evov, not a! dpidpiOvp.ev) ; time is an dpi6p.6s which is counted, not an dpidixos which we use as a means for counting (220 b 8). Time is the dpi6p.6s of continuous movement generally (223 b 1 ; cf. G. tV C. II. 337 a 23), not of any movement in particular ; nevertheless, what we usually mean by time, and what really " This meaning of apifljios is of course quite distinct from that in §§ 15-17 below.


APPENDIX A has the best claim to the name, is the dptdfios of the circular movement (ij kvkXw <t>opd), because the apidfios of this even, imiform, circular revolution is " most cognizable " (^23 b). And as everything is measured by some standard which is cognate to it {e.g., horses are measured or counted by the unit " a horse," see 220 h and 223 b), so time is measured by " a time," viz., by a determinate length of time ; and the time taken by the sphere of the universe to revolve is the " measure " par excellence : all other movements are measured by that movement, and time too is measured by that movement (c/. De caelo II. 287 a 23 ff., Phys. VIII. 265 b 8 ff.). Hence human affairs and all other things which have a natural movement and yev^ais and <l>dopa are spoken of as being a " cycle " : they are all discriminated by time, and their beginning and their end occur as it were according to some " period " (223 b). And further, since a movement may be the same over and over again, so too may time, e.ff., year, spring, autumn (220 b 12). (14) O. ^ C. II. 338 a 1 ff. If a thing's " being " is " neces- reV«<ris sary " {i.e., absolutely necessary ; see Introd. §§ 7-9), cyclical. then it is eternal (dt'Stoj) ; and if it is eternal, then its " being " is " necessary." " And also, if a thing's ycVecris is " necessary," then its yiveais is eternal ; and if its yevems is eternal, " necessary." Thus, if a thing's yfveais is absolutely, not conditionally, " necessary," its yev€<Tis must of necessity be cyclical and return upon itself {avaKVKXeiv kox dvaKa^TTTeiv) . [Proof of this. - YevfOLs must be either limited or not limited. We agree it not limited. If it is not limited, it must be either rectilinear or cyclical. If it is to be eternal, it cannot be rectilinear ; hence it must be cyclical.] Thus it is in circular movement and in circular yeveais that we find absolute necessity. This fits in with the doctrine (proved on other and independent grounds) that circular movement {i.e., the movement of the Heavens) is eternal ; for it is the movements which belong to this eternal movement, and the movements which are caused by it, which yCvovrai. and elaiv " of necessit}'." That which is moving round in a circle is always setting other things in movement, so that their movement too must be circular.

" Eternal being and eternal ycW<rt« are mentioned at G.A. 742 b 27, 31.


APPENDIX A Thus the upper <f)opd is a circular movement, hence the Sun's is too, hence the seasons yivovrai cycUcally, hence TO. vTTo rovTcov (cf. G.A. IV. 777 b 35 - 778 a 2) yivovrai cycUcally. Thus Water -> Air -> Water ; cloud entails rain, rain entails cloud. Tivf(Ti<s (15) Ibid. So far, so good. Why then do not men and cyclical ill animals apparently show this cyclical movement ? Why two'ni'odes ^^ they not return upon themselves, so that the same individual yiverai a second time ? In other words, why is it not " necessary " that you should yiveadai if your father does, although it is necessary that if you do, he should ? This looks like rectilinear, not cyclic, yeveais. Well, we must make a distinction and say that there are two ways in which things " return upon themselves " : some (a) do it numerically {dpiOfiw, i.e. the individual is numerically identical) ; others (6) do it specifically only (etSci /nwov, i.e., the specific form, not the individual, is identical). The difference depends .upon the character of the ovaia (see § 1) which is experiencing the " movement " : if (a) their ovaia is " imperishable," then obviously they will be the same dpifl/xoj as well as e'Sei ; if (6) their ovaia is " perishable," then they recur e'Sei only, not dpiOfico. That is why when Water yiverai from Air, and Air from Water, it is the same etSet only, not dpidfiu). Nothing, in fact, whose ovaia yiverai, i.e., nothing whose ovaia is subject to yeveais and <j>dopd, whose otJCTia is such that it admits of not-being, can remain same and identical dpiOfiai.

(16) The meaning of the last preceding paragraph will be clearer when we recall which are the things whose ovaia is " imperishable," not subject to yeveais and <f)6opd. They are the stars and planets. Their ovaia is free from all forms of change except circular movement ; hence each persists as an eternally identical individual ; its cycle is just its cyclical movement, <f>opd. As against these eternal ovaiai, we have such things as Air and Water, men and animals, whose ovaia is liable to notbeing, is " perishable." At first sight, says Aristotle, there seems to be a difference between Air and Water on the one hand and men and animals on the other. The " cycle " in the case of the former is obvious : rain is followed by cloud, cloud by rain, rain by cloud, continually ; but it is not so obvious in the case of men and animals. Although rain entails cloud, and cloud rain, in a continuous cycle, your father's yei-eaig does not necessarily entail yours, though yours entails his. But fundamentally the situation is the same in lioth cases, for (a) yeveais and (f>6opd shall never fail (§§ 12 and 14); there must always be a yeVo? of men, animals and plants {G.A. II), and the race will be continued even if one particular individual does not reproduce itself (this at any rate seems to be implied by Aristotle) ; (6) in neither case is there persistent identity of the individual : just as j'ou are different dpiBfiw from your grandfather, so is the rain which falls to-day different dpidyiu) from the rain which fell yesterday or last year.

(17) De anima II. 415 a 25 ff. Reproduction is one of the r«'v«<ris by functions of dpiTmicfi ipvxrj (nutritive Soul ; see Introd. reproduc§§ 41 ff.) ; and the " most natural " function of all living ^"^^"^ ^^ things is to produce another one like themselves " so attaining that they may partake in the eternal and divine in the eternity. way that they can " {'va rov dd koL tov deiov fierexoiaiv 3 Svvam-ai), since all things strive after this, and for the sake of this they do all that they do Kara. <f>vaiv. But they are unable to partake in the eternal and divine by uninterrupted continuance (awexfla), because no thing that is <f)daprr6v may persist as one and the same dpiBtiw ; hence they partake in it each in the way in which they can do so, some more, some less ; and so the thing persists not as itself but as something like itself {ovk avTO oAA' otov avTo) - i.e., as one, not dpiQp.u>, but etSet.

(18) Aristotle states more than once that the " matter " for The "perishable" things is to hwarov elvcu kox fir) etvai. "matter" E.g., (1) in G. (^- C. II. 335 a 24 ff. For things which 014^0^6. are etvai koL ij.t] elvai bward, the " material cause " (oTtioi' ws vXt]) is TO SwoTov eivoi Koi fj.r) etvat, which = TO y€VT)T6v Kol ^OopTov. (Thls Is t^vlcc stated.) Hence, the held in which yiveais and <f)dopd take place must be TO hwaTov elvoL Kal fti] elvai : that, then, is their " material " cause. Their " final " cause is their figure or " form " ; and there is a third cause or dpxq, viz., the " motive " cause. (2) In Met. Z 1032 a 15 ff. we read that ovaiai par excellence, the things which " we consider to have the fullest title to be called oucjiat," are animals and plants. And all (f>va€i. yiyvofjuva (as well,

of course, as all re'^vij ytyvd/xcva) have " matter," for each of them is Bwarov elvai koi /X17 etvai, and this is the " matter " which is in each of them.


The movmment of animals is ako caused by an unmoved mover.

M.A. 700 b 15 if., De anima III. 433 b 11 if. All the various stimuli (such as intellect, imagination, purpose, wish, appetite, sensation) which " move " animals are reducible to mind and desire {vovs and ope^is) ; hence the TrpwTov Kivovv of animals is the object of intellect and the object of desire (to opeKrov koX to SiavorfTov). And the npcoTov KI.VOVV Kivel ov kivov /xevov, in virtue of being apprehended in thought or imagination : it is, in fact, TO -npaKTov ayadov, the good which can be attained in the field of action. We thus have first (1) the object of desire, TO opeKTov, which Kivel ov Kivovfievov ; next (2) is desire itself, ope^Ls (or to opcktlkov, the faculty of desire), and this KLvei Kivovfievov ; last (3) is the animal, which is a Kivovfxevov ov kwovv - it gets moved without causing any further movement : it is the last term in the series. M.A. 700 b 30. Thus it is evident that in one respect every animal gets set in movement (Kivdrai) in the same manner as that in which the ael KivovpLfvov gets " moved " by the del kivovv (which Kivet cos epajfievov ; see App. A § 3) ; in another respect, however, there is a difference, for it is not " moved " det, but its every movement has a limit. This limit is to ov eveKu, the purpose aimed at by the movement, and when the purpose is achieved the movement ceases.

(3) M.A. 701 b 34 flF. (ch. 8). Putting the statement in § 1 Phygical above in a slightly different form, we can say that the accompani. origin of movement in the animal is to ev rat -rrpaKru) ^g°*g ^^ hitoKTov KoX (J)€vkt6v - thc objcct of pursuit and avoidance in the field of action : and since to <f>evKr6v is painful and TO Suu/cTov is pleasant, and since pain and pleasure are generally accompanied bj- cooling and heating, therefore the apprehension of these objects in thought or imagination produces of necessity (cl avayicqs) cooling and heating. Or again, in other words (ch. 7), desire (opefts), which as we have just seen (§ 1) is the ultimate, i.e., immediate cause of movement, is effected either through sensation, imagination, or thought, and these bring about dAAoiojffis (" alteration," i.e., qualitative change) of various sorts - heating, cooling, expansion, contraction.

(4) M.A., chh. 8-10. This ope^is, which brings about the Seat of animal's movement, must be situated in an apxjj (70;? a 2-2) desire. and this apx^ is the heart, or the counterpart of the heart in creatures which have no heart (703 a 14) ; besides, we can show independently that the dpx^ of the Kivovaa tjruxfi must be in a central position (70:3 b 15) ; arid of course ope^is is the opeKriKov faculty of the i/'"X^- Thus (701 b 28) when a sensation, or imagination, or thought produces an oAAoi'too-i? in respect of heating or cooling at the region of the heart, a great change or difference is produced in the body- «.<;., blushing, blanching, shivering, etc.

(5) It is important to notice that, according to Aristotle, the "Alteramovements of the living organism are not mechanicaUy tion" caused. In M.A., ch. 7 he compares the small original njovemen't" stimulus {KLirqais) required to set going an automatic of animals. puppet {cf. G.A., II. 734 b 8 ff., 741 b 9) with the small change (/icTajSoA^) that occurs at the apxq (viz., the heart) of a living organism and produces great and numerous changes or " differences " at a distance from the apxq {cf. G.A. I. 716 b 3, V. 788 a 11) ; but he takes care to point out that whereas in the automaton there is no aAAoia)ai?, no qualitative change - the action being entirely mechanical or " clockwork " - in the animal there is aXXoiwais ; in an animal one and the same part can become hotter and colder, larger and smaller - it dAAoiourcu.

'i.e., ipvxTQ operating in its faculty of desire - which is the " formal " cause of movement : it Kivel Kivovfievov. But tpvxtj is not material ; and in living bodies there must be some physical substance (aai^a) too which Kivel Kivov/jifvov. And this is the 211. It Kivel Ktvovfievov - Kivovixevov by the dpxT] which is the ^vxrj ; and that is why the SII is where it is. In fact, SIl is the " organ " or " instrument " of movement (see also De anima III. 433 b 18), capable of expanding and contracting, and in virtue of that capability it can exert force and so cause movement. And it causes movement by other means than aXXoicoms {fxTj aXXocdiaei) ; it undergoes no qualitative change itself, although it brings about changes of that sort in the parts of the body (and in the embryonic material, as we shall see).

Summary. Thus we must insert a fourth term in the series as originally stated in § 1 :

(1) The object of desire, to opeKrov, which klvci ov Kivovfievov ;

(2) Desire itself, opc^ty, which Kivel Kivovixevov ; {-2a) Hvfi^vTov Hvcu/ia, which also Kivel KLvovfifvov ;

(3) The animal, which Kivelrai, but Kivet nothing further.

For further references to the action of the heart and the pneiima, see below, §§ 31, 32.


Embryo formed by means of connate pneuma.

G.A. II. 741 b 37 ff. The parts of the embryo get delimited, marked out from each other {SioplCovrai), hy pneuma, but this is neither the pneuma of the female parent nor the embryo's own pneuma. This is proved by the case of birds, fishes and insects : some are separate from the parent, since they get their articulation in the egg ; some do not breathe at all, being produced out of larvae or eggs ; and even those which breathe and get articulated in the womb do not breathe until their lungs are perfected, and both the lungs and the parts which precede them get articulated before the creatures breathe. Further, the fissipede quadrupeds (dogs, etc.) are born blind, and the articulation of the eyelid is effected later. Thus we conclude that the same causes that are responsible for delimiting the young creature qualitatively are also responsible for its quantitative development - for actiializing its latent quantitative potentialities." And of necessity pneuma must be present, on vypov koI Oepnov, rov fxev TTOiovvTos, Tov 8e ndaxovTOS.

(8) The understanding of this last remark may be helped by a passage in M.A., ch. 8 and other passages. As we aecompanisaw (§ 3), the dpx^ of movement in the animal is " the ™®'^^* object of pursuit and avoidance in the field of action " ; and the thought and imagination of such objects is of necessity (e^ avay/ojs) accompanied by heat and cooling (§ 3). Bodily pleasures and pains are accompanied by heat and cooling either in some part of the body or all over the body. Hence there is good reason in the way the inner regions of the body and the regions around the dpxai of the instrumental parts have been fashioned - these regions change from solid to fluid and from soft to hard and rice versa. This being so, and " the passive factor" and "the active factor" (more exactly, "that which is so constituted as to act," and " that which is so constituted as to be acted upon ") having the character which they in fact have, when it so happens that the one is active and the other passive, and neither of them lacks any of the ingredients included in its logos, then immediately the one acts and the other is acted upon, and we get simultaneously, e.g., the thought " I must walk " and the movement of the limbs in walking- because the imagination produces the desire, the desire produces the aflFections, and these suitably prepare the instrumental parts.

  • This means that the same causes produce both the " uniform parts " (flesh, sinew, etc.) and also the " non-uniform parts " (face, hand, leg, etc.).

(9) Now we must remember that the " organ " or " instru- lastru' ment " of movement, that which bridges the gap between mental the immaterial ope^is on the one hand and the material "'^'"^t'5"^ °^ limbs of the body on the other, is the SII (§ 6) ; it is this pneuma which gives actual physical effect to the ope^is. ope^is (a) in desire ; thus, as Aristotle says, stands to the limbs in the relation of TTOiovv to Trdaxov, kivovv to Kivovfievov ; bxit so does the Sn too (§ 6). In fact, it is the SIl which brings about the "preparation of the instrumental parts" by causing in them the dXXoiioais of which they are capable : it actualizes their potentialities of changing from soft to hard, etc. (6) in (10) Returning now to the passage of G.A., it would appear that in the developing embryo also the SIl plays a similar role. It will be the £11 which gives effect to the formal cause in the semen so as to produce an embryo of a particular kind, just as in the other case it gives effect to the formal cause (viz., ope^is) and produces movement of the limbs ; here, too, then it will actualize the latent potentiality of the material, bringing about in it (741 b 12 ff.) the dXXoicoais of which it is capable - making it soft, hard, etc. Connate (u) With this in mind we can go on and interpret the rest of "" the passage which follows in G.A. II. 742-7 13. (1) The heart must be formed first, because it is the seat of the Hn." (2) The <j>Xe^es extend from the heart all over the body, and thus can act as channels for the blood (which is the " matter ") and for the Sn" (which is the vehicle of the " form," 729 b 20)- because {De resp. 480 a 10) " all the <f>Xepes pulsate simultaneously with the heart, and this pulsation is the pnevmatization of the fluid as it gets heated in the heart. (3) Some of the " uniform parts "' (by which term Aristotle means such things as flesh, nail, horn, sinew, bone) are formed by heat, others by cold ; and (740 b 1 8) the reasons why they are formed are (a) that the female's " residue " is potentially what the fully-formed animal itself is : all the parts are present potentially in the residue ; and (6) that (<"/. the very similar passage referring to opeKTiKTj i/ru;^ quoted in § 8 above) when " the active factor " and " the passive factor " come into contact " in that way in which the one is active and the other passive " (which means in the right manner, in the right place and at the right time), then immediately the one acts and the other is acted « These italicized phrases do not actually occur in the passage G.A. 742-743, but they are to be supplied from the doctrine of other passagf > here examined (see below, § 32) ; and we must realize that they rejiicsent perhaps the chief consideration, though unexpressed, in Aristotle'^ mind as he WTites the present passage.

See § 31 below.

upon ; the male suppl3dng the apx^ of " movement," the female supplying the material. It is Bpe-miicr) iftyxq which is the source of this movement (just as in the other case it was SpeKTiKT) tlwyq which was the source of the movement) - it brings about both generation and growth, for dperrTiKT] ijwxff and yewrp-iKTj ipv^rj are one and the same (see 735 a 17, 18). And the " organs " or " instruments " which it uses are heat and cold : its movement is " in " them. (This last sentence serves to emphasize the dual nature of SIl, dealt with in §§ 20 ff. below ; for of course SII is the primary " instrument " of BpiTTTLKT} </(U;^.) [Further important statements on these subjects are found in Meteor. IV. Hot substance and cold substance, says Aristotle, are " active " (because they bring things together, are avyKpiTiKa), solid substance and fluid substance are " passive." Tevems, i.e., natural change, is the work of these dynameis ; so is natural {koto, ^vaiv) (f>6opd ; these processes occur in plants, animals, and their parts, and are brought about by hot and cold substance, when those ex'^ai Xoyov (cf. G.A. m b 28), out of the substrate matter underlying each natural thing, viz., out of the " passive " dynameis. If hot and cold fail to gain the mastery over the matter, anei/iia results. Apart from destruction by force, the end of all natural objects is putrefaction : it may be defined as the Sdopd of the proper and natural {Kara <f>vaiv) heat in any fluid thing by the agency of alien heat (that of the environment), due to lack of proper heat, i.e., owing to cold ; hence hot and cold are the causes of putrefaction as they are of yeveais. Animals are generated in putrefying substances because the heat that was secreted in these substances is natural and is able auviardvai (see Introd. § 54). Cf. the whole Book, especially 390 b 2 flF.] (12) G.A. II. 743 a 20. It is not any chance material which Requisites gets made into flesh or bone, nor does it get made in any ^9 formachance manner or at any chance time, but only the gj^biro. material ordained by Nature, and in the manner and at the time ordained by Nature : that which is potentially X will not be made, actualized, into X by any motive agent other than one which possesses the actuality ; nor will a motive agent which possesses the actuality make an X out of any chance material. Heat is present in the seminal residue, possessing the right movement and actuality (evepyeia) to suit each of the parts ; and in the case of spontaneous generation the heat and movement of the season fulfil this same function." Connate (13) G.A. II. 736 b 30 fF. Every faculty of ./mx^ is connected with ^ a physical substance more divine than any of the four "elements " Fire, Air, Water, Earth, and this substance differs according to the degree of value of the tlivxT] concerned. There is present in the semen of every animal and in "the foam-like stuff" " the socalled " hot substance," which causes the semen to be generative : this is not of course Fire, but it is the pneuma which the semen contains, " the substance in the pneuma," which is " analogous to the element of the heavenly bodies," viz., the aither. That is why the heat of the Sun {cf. App. A §§ 9, 10) and the heat of animals (as contained in semen or any other such " residue ") is able to generate, whereas Fire cannot : the Sun, as we know already, consists of aither, and here we are told that there is in semen " something analogous " to aither. (14) It is now possible to see what Aristotle means when he says (737 a 17) : " It has now been determined in what way fetations and semen have i/fux^ 'â– they have it potentially, but not in actuality." This pneuma or vital heat is not in actuality ifivx^ ? but semen Kivelrai with a movement that is identical with that which moves the animal's body when the body is growing out of the " ultimate nourishment " (blood), and therefore when the semen gets into the uterus it sets in movement the female's " residue " with the same movement as that by which it KLveirai itself.

  • See further, § 17 and additional note appended tliere.
  • eoiKe KeKOLi'iovrtKevai, a usefully vague temi ; but at any rate it must be intended to denote a close relationsWp. We miglit express it perhaps by saying that this substance (viz., the pneuma, or more precisely "the substance in the pneuma") with which i/^vx^ 's thus a.ssociatP(i is the pliysical vehicle par excellence of ^vxv ; anyway, it is the first physical substance to give expression to the movements of tj/vxv ; it is its immediate instrument.
  • Perhaps intended to include the " frothy bubble " concerned in spontaneous generation ; see §§ 17, 19 below.
  • Of. the substance wiiich is " in " Air, Water, etc., which is also "in" aither, and wliich makes Air, Water, etc., transparent (§ 26).

(15) Thus we have an exact parallel with the action of opcktikt] Three i/wxTJ already examined above, § 6 : opeKTiK-fj tlwxq sets parallel in movement the pneuma, the pnetima sets in movement theories. the limbs ; dpeTrriKrj ( = yevvi7TiK^) i/'ux'? sets in movement the pneuma in the semen, the piuuma in the semen sets in movement the material supplied by the female. There is also a close parallel with the art of the carpenter (730 b 15 flF.) : the carpenter, in whose ilwxri is the " form " of the chair, moves his hands and instruments with a movement appropriate to the object that is to be made, and they in turn move the material so as to produce the chair." In all three cases no material part passes from the motive agent to the material on which it is working, but the agent imparts the " form " to the material by ineans of the movement which it sets up in the instrument.

(16) We have thus satisfied the requirement that only what Heart is X ire actuality can produce another X out of material formed which is potentially X : the parent which is X in actuality ^^^^' produces another X out of the female's residue which is X potentially, but there is an intermediary, viz., the jyneuma in the semen, which is an instrument possessing the requisite movement, a movement which is identical throughout, in parent, semen, and embryo (see also 734 b). The semen thus is i/n'X'? potentially (735 a 8) ; and the first things which it produces in actuality are dpeiTTucT] iffvxj and the physical seat thereof, viz., the heart. Later it produces in actuality sensitive ipvx^ as well. (Rational i/jvxrj, having no connexion with any physical substance at all, comes in independently from without ; 736 b).

(17) A similar situation obtains in the case of spontaneous SponUnegeneration {762 a 18). Animals and plants are formed o»s generain earth and in fluid because there is water in earth, and °"" there is pneuma in water, and there is Soul -heat (Otpyxni^s i/n/xiKT]) in all pneuma ; so that " in a way all things are full of i/iu;^." Hence plants and animals quickly form once this gets enclosed ; and when this enclosing " For another auch reference to pneuma as an instrument used by Xature, see O.A. 789 b 8 fl.


APPENDIX B -* happens, when the corporeal liquids get heated, a sort of " frothy bubble " is formed. Now the differences between the various creatures which are produced in this way are due to the stuff which makes up the envelope around the Soul-dpx^ (<•/. also 738 b 34: foreign seeds produce plants varying according to the soil in which they are sown, for it is the soil that provides them with their material and their body). We can now answer the question. What corresponds in cases of spontaneous generation to the " residue " of the female and the semen of the male in cases of sexual generation ? Just as in sexual generation the female by means of its heat concocts the " residue " (the menstrual fluid) out of the nourishment, so here the heat of the season by a similar process of concoction puts into shape a substance out of the seawater and the earth (762 b 14). That which corresponds here to the male principle in sexual generation is "that portion of the Soul-ap^^ which is enclosed in the pneuma " as described above ; this, just as the semen does, makes a fetation out of the material and implants movement in it." [Note. - It is, however, not clear in what sense there is anything in the case of spontaneous generation which is X in actuality {i.e., which possesses the " form " of X) comparable to the parent in ordinary sexual generation. The relationship of agent and material here would appear to resemble rather that of carpenter and timber (for which see § 15) ; but even so, granted that the requisite " movement " is present, it is difficult to see whence its specific character is derived ; for the Sun, etc., are " motive," not " formal," causes (App. A § 9).

In the case of the carpenter, of course, the " form " is in the carpenter's i/'u^'? (§ 15). From the passage referred to in § 17 it looks as though Aristotle falls back on the surprising explanation that it is the material only that determines what sort of creature is to be formed. If so, then we must assume that, given the agents, or " motive " causes, viz., ij'^xii pneutna, and the movement therein contained, though they are of no specific quality, the matter is formed by them into whatever creature it happens potentially to be.

^' Cf. § 12 above. 584.

APPENDIX B But in fact Aristotle himself is prepared to go even further than this. At Met. Z 1034 b 5 fF. he actually asserts that in the case of spontaneous generation of natural objects their matter can be set in movement by itself : it can supply itself with the same movement as that which the semen supplies (oaiDV ij vXt) Swarai /cat v(f>' avr'^s KiveiaOai Tavrrjv rrjv Kivrjaiv TJv TO airepua Kivel). That is to say, it can supply itself with everji;hing that in the normal way would have to be supplied by the " form " in the parent creature which is already X in actuality, or (in the case of arte/acta) by the " form " in the ifivxr} of the craftsman.

Perhaps Aristotle felt that this startling admission was in some degree justified by the notion that even " that out of which *" animals are generated is in a sense (f>vai,s (the e$ ov as well as the kuB' o and the ii<f>' ov of their generation is " <^rai?," Met. Z 1032 a ;24) " ; and, as we know, (ftvait never acts idly but always has a reXos in view. Regarded in this way, " matter," the e'f ov of living things, might be looked upon as considerabl}' more than mere lifeless, inert material : and in G.A. Aristotle does in fact ascribe even the possession of t/wxtj to it, as we have seen. Thus, to classify the statements he makes in G.A. : (1) The case of Testacea, which arise in sea-water. Water contains pneuma, and pneuma contains Soul-heat (§ 17). (-2) The case of animals and plants spontaneously formed out of putrefying matter. Mistletoe and similar plants are formed when either the soil or certain parts in plants or trees become putrescent (715 b 27 ff.). Now (i) Earth contains Water (§ 17), and, as we saw just now (ihid.). Water contains pneuma, which contains Soulheat. And Soul is obviously present already in the plants and trees upon which mistletoe, etc., grow, (ii) As stated in § 13 above {G.A. 737 a 3 fF.), the heat of the Sun and of animals can effect generation, and not only the heat of animals which operates through semen, but also any other natural residue which there may be has within it a principle of life. This is no doubt intended to cover putrefying animal and vegetable matter (expressly mentioned at H.A. 539 a -23 and 551 a 1 fF.), out of which some insects were supposed by Aristotle to arise, and " putrefying soil " as well, which would also qualify under (i) above.

A further palliative might perhaps be found in the con o See also the passages quoted at 741 a 1, n.


APPENDIX B sideration that in the case of animals it is sentient Soul alone which has to be supplied by the male parent, and for plants no sentient Soul is required. Testacea, too, were considered by Aristotle to be plant-like (see 715 b 17, 731 b 8 ff., 761 a 12 ff.)-]




Semen (18) To repeat first what we have heard so far of the nature '^'Z^ma °^ ^^ (^^ ^^ ^^ ^- ' see § 13 above) : There is in the semen of all animals the so-called 9epfj.6v, which causes the semen to be generative. This depfiov is not Fire, for Fire cannot generate any animal, but the heat of the Sun and of animals (the heat that operates through their semen or some other residue) can do so : for this does contain a vital principle {^cdtlktj dpx^). This substance which is contained in the semen is pneiima, and it is " analogous to the element of the stars," viz., aither. One obvious way in which it is analogous to aither is that it is generative, for the Sun, which is of aither, is generative (see App. A §§ 9, 10). We shall find other points of analogy later on (§ 25). Pnfuma (19) In the passage 735 a 29 - ^736 a 20 we are told that semen contains when it leaves the body is thick and white, because it has in it much hot pneuma owing to the animal's internal heat ; when the heat in the semen has evaporated and the Air has cooled, then it turns liquid and becomes dark in colour. Thus semen is a combination o{ pneuma (here described as " hot Air ") and water (kolvov ttvcvixaros Koi vSaros, to 8e Trvevfxd ean Qtpfxos arjp, 736 a 1 ) ; in fact, it is a foam, a mass of tiny bubbles. Similarly (762 a 20 fF.) in the case of spontaneous generation we have " a sort of frothy bvibble " formed, and this too contains pneuma, which contains Soul-heat (see § 17) ; cf. too the reference to " the foam-like stuff " (736 b 36) in which, as in the semen, there is enclosed pneuma, and in the pneuma a substance analogous to the aither. Thus pneuma is closely associated with heat- a special sort of heat, not the heat of Fire ; and at 762 a 20 we read that " there is Soul-heat in all pneuma." 586

APPENDIX B (20) Now although in all these passages the heat seems to Dual take the chief place, as it also seems to take the leading character part in the formation of embryos. Aristotle says more ofi"^**"'"than once that the embryo is formed by means of cold as well as heat (see § 11 above; 743 a, 762 b 15, etc.). And it would seem that pneuma really has a dual nature. This is true of it when functioning as the instrument of opeKTiKT] 'I'^XQi ^tI ^l^o when it is functioning as the instrument of yewrfj-iicr] i/fvxrj (see § 10 above). Thus {M.A. 702 a 10) the instrumental parts of the body can change from solid to fluid, soft to hard, and vice versa, and it is pneuina which brings about these changes. Aristotle tells us (703 a 22) that pneuma contracts and expands, and " has heaviness compared with fiery things and lightness compared with the opposite things " ; and that this power of contracting and expanding is indispensable to it in view of the functions it has to perform, because the actions of movement are pushing and pulling.

(21) De anima III. 433 b 18 ff. With further reference to Pneuma pushing and pulling, Aristotle in a brief reference in the effects De anima to the De niotu states that " the instrument b'y p*,J^hing used by ope^is in causing movement " is to be found and pulling, where a beginning and an end coincide, e.g., at a balland-socket joint : one remains at rest and the other is moved : and the two though separable in definition are not separable spatially ; for everjiihing gets moved by pushing and pulling. (See also Phys. VII. 243 a 12 if.) Compare too M.A. 703 a 12 : The "LYl stands in a similar relation to the Soul-dpx^ ^s the point in a joint (which /civet Kivov^ievov) stands to that which is unmoved.

(22) There is a passage in the De caelo (IV. 301 b 20 ff.). Air as an where again Aristotle is discussing the way in which instrument movement is brought about, and although he is talking '° effecting here of Air {a-qp) and not specifically of the kind of Air °i°^eâ„¢ent. known as pneuma, the passage is apposite to our present subject. Now of course according to Aristotle, some of the movement which takes place in the sublunary world can be accounted for bj- his theory that the " simple natural substances " Fire, Air, Water, Earth have a " natural " movement (see App. .\ § 2). But movement is also caused forcibly ; and force can either 587

APPENDIX B accelerate natural movement {e.g., it can make a stone go downwards more quickly than it would do naturally) or it can produce movement contrary to Nature {e.g., it can make a stone go upwards) ; it is in fact the sole source of unnatural movement. And in either case it uses Air as its instrument {wanep opydvM XPV^"-'- *? o-epi), because Air is naturally/ constituted to be light and heavy {'rre(f>vKe Kal Kov<f>os elvai kou. jSapuj) ; the Air, qua light, will cause an object to be carried upwards, for the Air gets pushed and receives the dpxTJ from the force which is exerting itself; qua heavy, it will cause the object to be carried downwards : the force " as it were hitches the movement on to {iva<j>ailiaaa) the Air and so transmits it to the object in either case. Hence an object which is set moving forcibly {i.e., contrary to Nature) continues travelling although that which set it moving does not follow it up ; and if there were no such physical substance as Air there could be no such thing as enforced movement." In the same way, says Aristotle, Air gives a fair wind to {avveTrovpiCei), helps on, natural movement. Dual char- (23) This dual nature of Air is not really so surprising as it acter of Air. sounds at first hearing, for {jDe caelo IV. 31 1 b 5 flF.) all the physical substances possess heaviness except Fire, and they all possess lightness except Earth. In its own place, each possesses heaviness, even Air ; thus, except in Water and Earth, Air possesses heaviness. At 312 a 12 ff. Aristotle lays down that the distinction of " form " and " matter " is to be found in the category of " place " as well as in the categories of " quality " and " quantity " : thus, to dvai belongs to the determinate, TO KOLTCj belongs to " matter." And taking the special instance of the " matter " of " the heavy and light," qua potentially X it is the matter of the heavy, qua potentially Y it is the matter of the light : it is the same " matter," but its ehau is not the same {cf. 310 b, 311 a). (24) For the important role of Air as a medium between the objects which give rise to sensations and the sense-organ, « It should be remembered that according to Aristotle nothing can exert any effect upon ("move") another thing unless it is in contact with it; see Phys. II. 244 a, b, and O.A. II. 734 a 3. That is why the movement must be "hitched on" to the Air; cf. H.A. VII. 586 a 17 ovSev yap ptTTxetTat noppoi apev ^tas jri'euju.aTtKrjs.


APPENDIX B and for importance of the role of pneuma in conveying the effects made upon the sense-organ to the heart and so to the i/wxtj, see below, §§ 26 S, ^ (35) We may now notice two other ways in which piifuma Pnewma is "analogous" to aither. (a) We noted above {§ 6)^°<iai7A«r that pneuma causes " movement " (both dXXoicuois and "aloKous. spatial movement) /iTj oAAoitoo-ei, i.e., without itself undergoing any qualitative change. In this respect it is similar to aither, for this too is not liable to any sort of " movement " (except circular <f>opd) ; Aristotle expressly says that aither is not subject to oAAoiWt? (De caelo I. 270 a 14. ff.), and he even goes so far as to suggest that it is " divine " (?70 b 10). (6) Pneuma, like aither, acts as an intermediary between an immaterial mover and material objects. As we have seen, the unmoved mover moves the Heaven and the heavenly bodies which are made of aither, and the heavenly bodies in turn " move " sublunary bodies, viz., they bring about the transformation of the elements into one another, and also they bring about yei/eai? and (jjdopd. So too the immaterial ipvx^ moves pneuma, and pneuma in turn causes aXXolcjais, thereby (i) moving the limbs of the body or (ii) causing the " movement " which is the development of the embryo.

IV. THE FUNCTION OF Sv'/x^urov Xlvivua IN SENSATION The following outline of Aristotle's theory of Sensation will indicate the important part played in it by Air and pneuma. It will be seen that just as pneuma transmits to the parts of the body the movements caused by i^x^ and thereby produces cL\Aoia>crts and movement, so in the reverse direction it apparently transmits to tjivxri the movement of the oAAoioiffi? caused in the sense-organs by the movements of external stimuli.

It will be convenient to divide this account into two parts : A. dealing with what goes on outside the sentient body ; B. dealing with what goes on inside the sentient body.



A Vision. (26) Visi?hi. - Vision is effected in the following way (Be anima II. 418 a 27 if.). There are three main factors : Colour, the medium, and the sense-organ.

" Colour " means " that which has the power to set in movement that which is actually transparent " (to /car' evepyeiav 8i,a(f>avds), and the latter acts as the medium. The medium extends continuously from the object to the sense-organ, and in its turn sets the sense-organ in movement. The medium is indispensable, because - colour cannot set the sense-organ in movement direct. According to G.A. V. 780 b 34 ff., accuracy in seeing distant objects depends upon the movement of the medium not being dissipated, but " getting a direct passage " {evOvnopeiv) ; indeed, the best results would be obtained if there were a continuous tube between the object and the eye (781 a 9). Compare the case of Hearing, § 27.

Examples of transparent media are Air, Water, and "tertain solids. Their transparency is due not to themselves, but to the fact that they contain a certain substance which is also found in the " eternal substance of the Upper Cosmos " (eV roi diSt'oi tu> avw awfian), i.e., in the aither. Of this substance the actualization is Light ; and its actualization is brought about by the agency of Fire or something of a similar kind as the substance of the Upper Cosmos - for this selfsame substance is present in both." Thus Light is essential if vision is to take place, because it is only when the substance in the medium is actually (not merely potentially) transparent that it can be set in movement by colour. Hearing. (27) In the case of the other senses too a medium is indispensable ; one example may suffice. In Hearing there are again three main factors : the sounding object, the Air, and the sense-organ.

" A sounding object " {il)o<f>-qrt,K6v) means " an object which can set in movement a continuous volume of Air as far as the aKori " (the organ of hearing), and the movement of the Air constitutes sound only when the n The obscurity of this sentence is due to Aristotle's text, not to my presentation of it.

Appendix B

Air is thus set in movement as one continuous entity and is prevented from being dissipated. (This requirement necessitates that the object struck should have a smooth surface, otherwise the Air cannot be moved as a unity.) Hence here too the medium must be continuous between the sounding object and the sense-organ ; and its movement in turn sets in movement the Air in the ear {De anima II. 420).

B (28) Since {De sensu 438 b 7) there must be light within the Vision. eye as well as in the external medium, the ej-e also will have to be transparent ; hence the eye, or rather that part of the e3-e which sees, viz., the ko'^ or pupil, is made of Water {H.A. I. 491 b 20, De sensu 438 a 13 ff., P. A. • II. 656 h 1, O.A. V. 779 b 23 if.). Thus the external medium and the internal constituent are both transparent. The substance used for the eye is Water and not Air because ^^'ater is more easily kept in a confined space than Air {De sensu 438 a 15 ; P. A. II. 656 b 2). And it is of course the movement of this part qua transparent, not qua fluid, that constitutes sight {G.A. V. 780 a 4 ; cf. De sensu 438 a 13 ff.). If the fluid in the eye is already in violent movement owing to some earlier stimulus, it cannot respond to a fresh movement from without {O.A. V. 780 a 8 ff. ; <•/. a 23).

(29) The sense-organ of Hearing is of Air {De anima III. Hearing. 425 a 4 ; cf. P. A. II. 656 b 17 ; G.A. V. 781 a 23) ; and 'the Air in the ear is built into a chamber (eycaTajxroSdfirp-ai) in order to keep it free from disturbance {npos to aKivrjros (Ivai), SO that it may take up the movements conveyed to it from without, ottcjs aKpi^ius aladdvrjToi Ttdaas Toj 8ia<f>opds rrj^ Kiirqaecus {De anima II. 420 a 10; cf. the very similar phrase frequently used in G.A. V. T79 b - 781 b). This Air in the ear is also described as " connate " (ov/xi^utj? ; De anima II. 420 a 12) ; and it is this Air with which we hear. It is itself always in movement with a proper movement of its own (oiVeia Kimqais) ; sound, however, is of course not this proper movement, but a movement derived from something else {dXXoTpios).

Senseorgans connected to the

  • Ae/Ses connected to the heart, the source of the connate pneuvia.

(30) Now sensation arises from the heart, the seat of aluO-qTiKT) tpvx^ (17 atadrjais oltto rrjs KapBias, P. A. II. 656 b 24 ; cf. 656 a 28, III. 666 a 12, also II. 647 a 25 and O.A. II. 743 b 25), for no bloodless part has the power of sensation, nor has blood itself ; the power resides in " one of the parts that are made out of blood " {P. A. III. 666 a 17, II. 656 b 19). Hence the movement in the sense-organ must somehow be conveyed to the heart. Now it is evident that the senses of touch and taste are connected to the heart {P. A. II. 656 a 29 ; cf. De sensu 439 a I ) ; so are the others, though perhaps not so obviously and directly. Thus, from the eyes " passages " (TTopoi) run to the ^Ae'jSts around the brain, and similarly from the ears a " passage " connects to the back of the head {P.A. II. 656 b 17). This is confirmed and amplified by G.A. II. 744 a 2, where smell and hearing are said to be " passages " full of 211, connecting with the external Air, and terminating at the ^Ae/3ta ichich come from the heart and extend around the brain.

(31) In the passage of G.A. V. 781 a 23 ff., which is perhaps out of place and possibly slightly corrupt, some important statements are fortunately clear. We read there that the " passage " of the organ of hearing terminates in the region where the SII produces the pulsation (deriving, as will be seen, from the heart) ; and we also read of the " movement " which comes through the senseorgan of hearing (presumably to its destination in the heart) being reproduced again through the voice ; at any rate, it is clear that the heart is the dp^i? o( the voice (IV. 776 b 12 ; cf. V. 787 b- 788 a). Further details about the pulsation are given in I>e resp. 479 b 30 if. Pulsation, says Aristotle, is similar to boiling, which occurs when fluid substance is pneumatized by TO depfxov : the fluid rises up owing to increase of bulk. Pulsation is produced in the heart by the increase of bulk, caused by heat, of the fluid which is continually being supplied to the heart from the nourishment. This action goes on continuously, because the blood is fashioned first of all in tlie heart, and the inflow of the fluid out of which the blood is produced goes on continuously. And all the ^Ae'jSes pulsate too, simultaneously with each other, because they are all connected to the heart. Pulsation is, in fact, " the pneumatization of the fluid as it gets heated."

(32) This seems to give us the key to the theory of sensation Continuity as well as the explanation of the upkeep of the SII. The °^ ^^'^ fluid, as it gets heated and thereby concocted and turned ^^nui into blood, is " pneumatized." This no doubt implies from sensethat the pneuma which is already present in the fluid (as organ to it is in any fluid ; see § 17 above), and which contains ^^^^^ Soul-heat, acquires some special character or rather " movement " by being brought into contact with the heart, and with the Soul which has its seat there and whose " instrument " the pneuma is destined to become ; indeed, we must assume this, because semen contains the pneuma which possesses the specific " movement " that is to fashion the embryo (§§ 9, 14 above), and it is from blood that semen is made by further concoction. Hence blood will contain SIT, and we may say that all the (f>Xepes are instinct with 211 as well as with blood. Hence there Ls continuity of SIT (or of " the substance similar to aither," if this is really to be distinguished from SII) from the sense-organ, through the " passages" and then the ^Ae'/Sej, right up to the heart. M'e have Aristotle's explicit statement that the " passages " of â– smell and hearing, which are full of SII, terminate at the (^Ae'jSia which come from the heart, and that the " passage " from the eyes does so too. And the (^At'jScs of course pulsate owing to the " pneumatizing " action set up in the heart.

(33) As Beare says on the last page of his book, Greek Conclnslon. Theories of Elementary Cognition (p. 336), " if we could discover all the properties and functions of 211, we should have penetrated to the inmost secrets of senseperception " as envisaged by Aristotle ; for " the 211 was the profoundest cause and the most intimate sustaining agency from the beginning to end of life and sensory power."

The Index is to be regarded as supplementary to the Contents-Summary on pp. Ixxi ff. ; see also the Introduction and Appendix.

The method of reference is this : Roman numerals refer to pages of the Preface. I denotes paragraphs of the Introduction. A and B denote paragraphs of Appendix A and B. The numbers 15a to 89b (standing for 715a to 789b) refer to the pages and columns of the Berlin edition which are printed at the top of each page of the Greek text. The lines are referred to in units of five lines : thus 17al = 717al-4. 17b5=717b5-9 f, ff= following section(s) of five lines, following page(s) etc., as the case may "be. In the text references, each entry is separated from the preceding one by a dash (/), unless they both have the same Berlin page-number.

References throughout include footnotes. (This applies equally to the entries which refer to the Greek text. For example the mention of W. W. Jaeger in the footnote to 719all is listed as 19al0.)

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  1. In the translation I have retained tlie traditional rendering " cause " for alrCa, although perhaps in some contexts " reason " or " explanation " might have been a closer rendering ; but a variation in the English term might well produce more obscurity than clarity.