Talk:Book - Contributions to Embryology Carnegie Institution No.10

From Embryology

The Human Magma Reticule in Normal and in Pathological Development

By Franklin P. Mall.


Students of embryology are familiar with the jelly-like substance found in the human exoccelom, which varies much in appearance in different specimens. Some-times this substance is gelatinous, with, delicate fibers; at other times it is mixed with granules; and, in extreme cases, it forms quite a solid body. I think it was Giacomini who pointed out definiteh' that the morphological appearance of the magma determines, with considerable certainty, whether or not the contained embryo is normal or pathological. We are indebted to him for about a dozen papers on pathological embryologj^, a summary of which he published in ^lerkel-Bonnet's Ergebnisse. In this summary the following statement is made:

" In the early stages of development we can determine by the extent of the exo^tElom and its contained magma whether or not the embryo under consideration is normal. A large coelom, con- taining a rich magma, with its meshes sufficiently filled with a flaky precipitate to mask the embrj^o, is a certain sign of pathological development."

It is well known that the magma is least conspicuous in fresh specimens and becomes more pronounced after being hardened in alcohol or other preservative fluids. In recent years it is found that magma shows to the greatest advantage in specimens hardened in formalin; the fibrils are somewhat tougher, but the magma has usually the same appearance as in the fresh state. However, the experience of embryologists has been that the magma is more pronounced in pathological speci- mens, and for this reason it has been suspected that it does not exist in normal devel- opment. In fact, the illustration of the magma given bj^ Velpeau in his monograph — in which he first uses the term "magma reticule" — is undoubtedly of a pathological specimen. A glance at the other plate which accompanies this handsome mono- graph shows clearh^ that most of the specimens he describes are decidedly pathologi- cal. During the 80 years which have elapsed since his time, embrj'ologists, through comparative study, have been able to separate normal from pathological embryos with considerable precision; and in the abortion material, as collected in various laboratories, far over one-half of the specimens of the first 2 months of pregnane}^ are pathological, and in them we usuallj'^ find a highly differentiated magma. How- ever, if normal specimens are studied with care, we find that thej^ too, contain some magma; therefore, magma must be viewed as a normal constituent of the human ovum.

It has been shown by Keibel that there is marked magma within the exocoelom of monkey embryos. In specimens containing embryos 1.3 mm. and 5 mm. in length, he describes it as a flaky, reticular mass outside the amnion, and speaks of it as coaguluni composed of reticular magma which had to be removed before the embryo could be seen. Undoubtedly he was dealing with normal specimens, thus showing quite conclusively that a delicate magma must be viewed as a normal constituent of the exocoelom. According to Keibel's figure 7, the magma appears to he ilenser in monkeys than is usually the case in normal human specimens. How- ever, a very dense magma in human specimens invariably indicates, as was first demonstrated l>y Giacomini, that the ovum is pathological.

The best account of magma reticule is given bj- Retzius, who brought the subject up to 1890, and left it with the conclusion that magma reticule is a normal constituent of the human ovum. The statements of the earlier embryologists, from the time of Haller, are mainly of historical interest; but these investigators were at times inclined to view magma as a "middle embryonic layer" of the ovum, and, again, they believed it to represent the allantois of lower animals. Retzius rein- vestigated the subject, taking into consideration normal as well as pathological embryos, and his conclusion is that magma is present in both kinds. His own words are as follows:

" Bei (ler Oeffnung des Chorionsackes der Eier des ersten und zweiten Monats sah ich, wie in der Einlcitung crwalint wuitlo, und dies oft, am bcsten nach kurzer Erhartung in Ueberosmivimsiiure (von 3.1 Proc.) odor in Miillcr.sclRT Lusunfi ip'wcihiilich nach doiipeltor ^'ol•dunIunlg) , in dcni scliloi- niigcn Irihalt, wclclicr zwisi-hcii dcni Chorion unil dcm Amnion, also im sulK'horionischfn Kaume vorhandcn war, diiiuioro odor dickere Fiidcn und J^triingc, (He mehr oder wcnigor dicht von der aus.*<orcn Fliiche des Amnion zur inncren Fliichc des Chorion hinul)orIicfen, um sicli dort mit ihrcn Enden an den beiden Hautcn zu licfcstigcn, indcm sie sich oft an ihnen vcrbreitcrtcn und in ihre U-kleidende Schicht iibcrgingen. Diese Faden und Striingo, wolehc im frischen Priiparate kaum sichtbar waren, traten nach der Behandlung mit den erwahnten Fliissigkciten deutUch hcrvor. In der Fig. 15 der Taf. X^'III habe ich ein seiches Ei abgebildet. Das stark zottige Chorion (ch) ist geoffnet, und man sieht im subchorionischen Raume den Amnion.sack (a) an weisslichcn Strangen (m) aufgehiingt liegen.

" Die Strange, welche im unerhiirtotcnZustandecinc scliIcimigfasorigoConsistcnzhaben,sichaber ohne Schwierigkeit Stiickweise au.ssclineiden iiussen und dann in Mikroskope eine ileutlich f;iserige !>truc(ur darbieteii, zeigeu nach der JCrhiirtuug einen ausgcjjriigt fibrillaren Habitus. In einer homogen, structurlosen (iruud.substanz tretcn Zlige echtcr bindcgcwebiger Fibrillen hcrvor, welche oft eine Hauptrichtung ein.schlagen, also ziemlich parallel verlaufen. Jedoch konimen auch viele sich kreuzende Fasern vor. Hier und da bemerkt man dickere Biindel verschiedenen Calibers welche aus dicht gedriingten Fibrillen besteiieii. Es sind also fibrillar-bindegewel)igo Balken, welche (lurch cine homogene, zahlreiche einzelne Fibrillen enthaltende Intercellularsubstanz ziehen. Zwischen den Balken und Fibrillenzugeii sieht man recht zahlreiche Zellen, welche theils und am moisten rutuUich oder oval, theils auch s])in(lelf()rmig sind und in ihrem oft reichlichten Proto]ilasma gr().s.serc Klanzendc Korner enthalteii. Diese Zellen liegen in der (Irundsubstanz ohne Ix-soiidere anordnung zerstreut, bilden keine Scheiden o. d. um die Filjiillenbiindel.

"Man hat es hier ofTenbar mit einem iiurcifcn B i itdcgcwcbe zu ihun, inncm cmbryoiuilcn mucosen liindcgnvebf, irclchcg imlesmn in drr Kitlwickluiuj zum jlbrilUircn liindcycH'cbc schon tccit vorgcschritcn ist."

\\v have now in the litcTaturc a detailed description of a number of young litunan ova, smd, according to their clinical histories, some of them, at least, must be normal. The da.ssic specimen is that described by Peters, which came from a woman who had committed suicide. The specimen was hardened in situ in an approv('<l manner, and was worked up and de.'^cribed under the best ])ossible con- ditions. In it the co'loni is filled with a gelatinous substance, through which radiate


delicate bands of fibrils, among which appear scattered nuclei. Near the embryo there is a small si)ace, the interi)retation of which was verj^ difficult at the time the specimen was described.

Since Peters studied this specimen, the sections have been carefully reworked and discussed in a critical way by Grosser, who gives a new interpretation in two figures and states that the cavity of the ovum contains reticular magma which is partly made up of heavier strands of tissue accompanied by nuclei. In the neigh- borhood of the embryo there are two large spaces, hned with cells, which appear to be the primitive body-cavities. In his work on the comparative development of the embryonic membranes, Grosser describes this space in great detail and also gives us two new illustrations of the embryo in his plates 3 and 4. According to this authority these two body-cavities communicate b.y means of a slit-like canal just behind the umbihcal vesicle (Grosser's figure 31, plate 4). This interpretation of the Peters specimen shows that the cavit}' of the ovum is first filled with a free mass of reticular magma, after which the coelom begins to form near the body of the embryo. As this cavity expands subsequently, it probably first destroys the more delicate strands of magma, leaving the heavier ones; thus in a short time the cavity of the ovum is lined b}- the endotheUum of the coelom, which also must cover the stronger bands of magma radiating as trabecula> throughout this cavity (Grosser, pp. 78 and 79).

Keibel explains the formation of the human coelom as follows:

■ It is, however, not quite clear how the cavity traversed by scattered strands of mesoblast and lying between the yolk-sac and the chorion in the Peters ovum is to be interpreted. It may be sup- posed to represent the extraembryonic coelom; but it may also be imagined that it has arisen from an extensive loosening up of ths tissus, and not by a splitting of the meso Jarm, and that the triangular space between the caudal extremity of the embryo, which is lined with flat cells having an epithelial arrangement, is the first jmrnordium of the coelom."

A condition similar to that found in the Peters specimen has been observed by Lewis in the Herzog specimen, which is of about the same stage of development. Lewis says (see his paper, p. 300) that there are occasional clefts in the mesoderm of the chorion of the Herzog embryo, but that they are of doubtful significance. His reconstruction shows a strand of mesoderm, more pronounced than m the Peters ovum, extending from the yolk-sac to the chorion and circumscribing a space on the ventral side of the embrj'o.

Eternod has written several papers in which he describes the formation of the exocoelom and the fate of the magma reticule. He sa3-s that it first fills the entire space between the primordium of the embrj'o and the chorionic wall. Later, larger spaces appear within the substance of the magma, leaving denser strands of magma fibrils to support the embrj-o wdthin the gradually expanding chorion. In general this coincides with the opinions just cited.

' The relation of the exocoelom to the magma Ls strikinglj- shown by Waterston in a section of a small embryo in situ. The space between the embryo and the chorion is fiUed with a dense mass of fibrils, into which the exocoelom is burrowing. Waterston's figure 1 shows the relation of this cavity to the magma, and only near the embryo is the exocoelom lined with a layer of cells. "When this figure is compared with C.rosscr's figure of the Peters ovum, it becomes clear that the two si)aces in the latter are in reality the beginning of the exocoelom.

Tlie .>;tuclies referred to above indicate that the space near the embryo i.s the primitive exoccvlom and that the remainder of the so-called cavity of the chorion is .•dimply the young normal ovum filled with delicate fibrils which communicate freely with the fibrils of the chorionic membrane. We have in our collection a young normal specimen, No. 763, containing an embryo anlage 0.2 mm. in length, which in general confirms the observations in the Peters ovum. A hst of the normal speci- mens in our collection discussed in this paper is given in table 1.

Table 1. — List of normal embryos

Cat. No.


of embrj'o

Dimensions of chorion.

Men- strual age in days.

Condition of magma.




of embryo.

Dimensions of chorion.

Men- strual age in days.

1 Condition of magma.







4X 2.2


Some reticular.



19X15X 8


Strands of magma.








14X11X 6


Reticular exce.ssive.






1 836




Delicate reticular.




Few strands





Small amount of magma


3 9

17X12X 7


Much reticular.

around cord.



22 X22 X22






Small amount of mayma.





Very few fibrils.


Specimen No. 763 was removed from a woman who was the mother of 6 children, the oldest being 10 years old. She had had one miscarriage. During the year before the operation she suffered much from headache and backache, but otherwise her health appeared to be normal. When she was admitted to the hospital she complained of abdominal enlargement and there was some urinary disturbance. At the operation for rupture of the perineum the uterus w'as scraped out ; subsequently the ovum was found in one of these scrapings. The fragments both of the mucous membrane and ovum appear to be normal.

Unfortunately we have only a few of the sections of this valuable specimen, but these show that we are undoubtedly dealing with a normal ovum of the same stage of development as that described bj' Peters. The chorionic cavity is ])artly filled with mother's blond, ])ut there are some strands of reticular magma, with nuclei and protoi)lasm radiating through the blood. The specimen has been staimnl in hematoxyin and eosin, which is not esjiecially favorable for defining magma fi])rils.

The specimen described by Ilerzog is also undoubtedly normal, as it was obtained from a woman who was killed by a stab-wound through the heart. The large colored plate i)ubli.shed by Herzog shows the specimen to be quite identical with that of Peters. It shows free cells in the coclom, which contains no other foreign substance, but a i)hotograph (figure 24, published by Ilerzog) shows that the cu'lom is filled by a very pronounced substance, reminding one very much of reticular magma. The same is true of a specimen recently described by Johnstone. A colored photograph which he j)ublished shows quite distinctly a pronounced magma throughout the coelom. (See, for instance, his figure 3.) This establishes definitely the i)resence of reticular magma in ova the size of the si)ecimen of Peters. AVe have, however, the valuable specimen of Bryce and Teacher, which also shows the condition of the magma in an earlier stage. In this specimen the chorionic cavity is filled with a dense mass of fibrils, throughout which are scattered numerous nuclei, as shown in their plates 3 and 4. The specimen was not perfectlj^ hardened and there is a small cleft between the chorionic wall and the mass of magma. As .vet there is no exocoelom, showing that it is younger than the Peters specimen.

jMore advanced stages of the condition of the magma are represented in the specimens described by Jung and by Strahl and Beneke. In the Jung spccunen the cavity of the ovum is filled with a very pronounced magma, running together in stronger bands, as in our own normal specimen. No. 836, to be described later. The larger cavity Jung marks "exocoelom," but it is not clear that this is lined with endothelium. From his large illustration one gains the impression that the speci- men is somewhat pathological, for it is of the same type as numerous specimens in our coll?ction with embryos that are usually found to be pathological. Taking the illustrations given in Jung's plates 1 and 2, the specimen again appears to be patho- logical, and I should be inclined to pronounce it such did not his plate 6, figure 17, show this same section on an enlarged scale, which gives a very sharp outUne of dif- ferent embryo structures and scattered through them are numerous cells undergoing division. It would be impossible, with our present knowledge, to accept such sec- tions as coming from a pathological embryo. The specimen described by Strahl and Beneke is of about the same stage as the Jung specimen, although the magma does not seem to be so well pronounced. It is unequal m and has scattered through it deUcate strands, as shown in their figure 63. In fact, the above-described specunen underlies also the diagram on the form of the ccelom given by Strahl and Beneke on page 18 of their monograph.

]\Iagma of uniform consistency, as seen in the Bryce and Teacher specunen, soon arranges itself in bands, which gradually become more and more pronounced in older specimens. Between these bands are spaces filled with fluid, and those spaces near the embrj^o become lined with endothelium to form the exocoelom. There are other spaces between the exocoelom and the chorionic wall. The sharper bands of magma fibrils — well shown in our embryo No. 836 (plate 1, figs. 3 and 4) — apparently support the embryo and the wall of the exocoelom within the chorion.

We have in our collection an excellent embryo. No. 391. which is a Uttle larger than that described by Strahl and Beneke. This specimen came to us in formalin and was opened with great care. It was found that the embryo and appendages were suspended bj^ means of numerous delicate fibrils which radiated from them to the chorionic wall. As the sections were stained with cochineal, the fibrils do not show in them, so that this description is based entirely upon the apearance of the uncut specimen. In general the specimen appears to be normal.

Our specimen No. 779, somewhat older than the one just mentioned, apparently contams no magma. It also was hardened in formalin. The ovum is entirety covered with vilU, which branch twice, are of uniform size, and appear to be normal. In the main chorionic wall there is a pronounced fold. The specimen was bent along the line of the fold, but the chorion was gradually dissected away with the aid of direct sunlight. The chorion is entirely Imed by a smooth membrane, and contains a cavity wliich is filled with a clear fluid and which apparently contains no magma, ^\■ithm there is a clear, worm-like body, which is bent upon itself, with another body ari-sing from the middle of the bend. Apparently this is a flexed emI)ryo with the umbilical vesicle attached to it. The body is of uniform diameter, mea.^^uring less than a millimeter. We are probably dealing here with a normal ombryo. In opening this siiecimen great care was taken not to touch the embryo, so as to avoid injuring it. The embryo was taken out and cut into serial sections. It contains 14 somites and is without limb-buds. The sections give the impression that the embryo is pathological. There are no data in the history of the case which bear upon this point; therefore, for the present we may view it as a normal specimen without magma — or, if the embryo is taken into consideration, as a pathological specimen with dis.solution of the magma. Usually in pathological specimens the magma is greatly increased in quantity.

No. 104 is a somewhat older specimen. It came to us from an autojjsj^, with the entire uterus, and the sections of it indicate that the embryo is undoubtedly normal. The only record of the magma which we now have is given by several photographs which were taken at the time we received the specimen. These show a few strands of reticular magma, without any granular magma, radiating from the embrj^o. The i)hotograi)hs were taken while the sjiecimen was in formalin.

The next s]iecimen, Xo. 463, is somewhat more advanced in development and contains a flexed embryo, 3.9 mm. in length. The ovum is covered completely on one side, and partlj' on the other, with villi 1.75 to 2.75 mm. long. On the partlj^ co^•ered side the villi leave relativelj^ bare one area, centrally situated, measuring 8 by 4.5 mm. Over it the villi occur onh' here and there, about 2 mm. apart, and are branched and apparently normal. On opening the ovum the reticular magma is f(»und to (ill the exocoelom. By carefully exploring with fine tweezers, an ai)i)arently ncjrmal embryo is seen with a j'olk-sac measuring 3.5 bj- 4 mm. The embryo has anterior limb-buds and at least three gill-slits which are visible externally. No note was taken at the time regarding the condition of the magma, but sections of the entire chorion show that there is a very decided reticular magma between the embryo and the chorionic wall. There is no granular magma. The magma is composed mostly of fibrils, of much the same appearance as tho,sc of mesenchyme. Ik'tween the network of magma fibrils are denser strands accomi)anied by cells. In the fresh state imdoubtedly the denser strands would appear as filn-ils, while the rest would be transparent and jelly-like. The specimen came from a woman who was i)erfectly healthy and had given birth to 2 children durmg the last 4 years. This was her first miscarriage, and there was no indication of uterine disease.

Specimen No. 486, of the same degree of development as the one described above, is in a perfect state of i;)re.servation, but there is no historj'^ which would indicate whether or not the specimen is normal. However, the chorion is covered with vilh about 3 nun. long, with a bare spot on one side about 4 nun. in diameter. The sections of the embryo do not show any attached fibrils of magma, but the chorionic wall, after hardening in alcohol, shows a decided layer of magma attached to it.

No. 470 is an interesting specimen, as it was found floating in a ma.s.s of blood- clotfi, which were sent to the laboratory in formalin. The ovum is covered with


normal villi and contains a well-formed embrj'o within the amnion. It is apparently normal in every respect. No magma could be seen at the time, but drawings of the embryo subsequently made show delicate strands of fibrils forming a fuzzy laj'er around the umbilical cord and extending over the umbilical vesicle: undoubt- edlj^ these are magma fibrils. This seems to be the normal condition for this stage and is verified in specimen No. 836, to be described later. Sections through the mass and the chorion, stained with carmine, show the magma as a granular mass; only at points is there any indication of fibrils. However, this mass resolves itself into the most definite fibrils when colored with Van Gieson stain, in ^lallorj'^'s stain, in hematoxylin, aurantia and orange G., or in iron hematoxylin. With Van Gieson stain the fibrils take on fuchsin color about as intenselj' as do the fibrils of the chorionic wall, with which thej' are continuous. The contrast obtained with ^lallory 's stain is quite marked, as the endoplasm of the mesenchj^me of the chorionic wall stains shghtly blue, while the exoplasm and the fibrils of the magma reticule remain unstained. This difference is not shown in sections stained in iron hema- toxylin, as all fibrils are colored intensel}^ black. However, it does not come out with the Oppels-Biondi method or with hematoxylin and eosin or aurantia. As the fibrils of the magma are continuous with those of the exoplasm of the chorionic wall, which do not stain in jNIallory's connective-tissue uiLxture, they can not be considered as white fibers, and from their failure to stain in Weigert's elastic-tissue mixture thej' are not elastic. As will be shown subsequently, they give the reactions of embryonic connective-tissue s}Tic5'tium; and this is Retzius's opinion regarding their character. In specimen No. 486 the fibrils of the magma are not accompanied by any nuclei; so they must be viewed as belonging to the cells of the chorionic wall, from which they extend to bind the chorion with the primordium of the embrjo.

Specimen No. 588 came from a woman who had 2 children living, aged 14 and 20 years respectively. Since the last birth she had aborted 11 times, and in the opinion of her phj'sician all the abortions were due to mechanical means. This indicates that the specimen is normal. A figure of this embryo with strands of magma radiating from the umbilical cord and vesicle is shown in plate 3, figure 2.

Specimen No. 136 is of about the same stage of development as No. 588, although the chorion is covered with poorly defined viUi. For an embryo of this stage it is unusually small, and I have therefore Usted it with the pathological specimens in my paper on monsters. A photograph of the ovum after it had been cut open shows that the chorion is completely filled with reticular magma, so that the embrj'O is practically obscured. A block of the whole ovum encircling the embryo was cut in serial sections. These show that there are strands of tissue accompanied by cells which form partitions in the exocoelom. The quantity of the magma appears to be somewhat excessive for a normal o^'um of this stage of development.

No. 836, a perfect specimen containing an embrj-o 4 mm. ia length, settles definitely the condition of the magma at this stage of development (plate 1, figiu'es 3 and 4). In this ovum the exocoelom, measuring 9 by 4 mm., contains a dehcate spiderweb-like reticular magma, several of -the strands being considerably larger than the others. ^lost of this magma occurs between the yolk-sac and the amnion

Miul the adjacent ehoiionic \v;ill wlicic tlu' fibrils are unusually abuiulant. This speeiinen was ohtaiiieil from a hystereetoniy upon a woman, 2o years old, for a fibrous tumor of the uterus. She had been married 4 years, this being her first pregnaney. There were no special symptoms bearing upon the case, excepting the discomfort which accompanied the tumor of the uterus. Her last menstrual jx'riod had been delayed, and as it had been more jjrofuse than usual she believed that she h:id had a miscarriage; otherwise, everything ai^peared normal. This w-as con- firmed by a careful examination of the specimen, which showed it to be normal in every respect. The uterus was opened by the surgeon at the time of the operation, but fortunately the site of the ovum was not injured. The specimen was sent to the laboratory innnediatcly. where it was fixed In- Dr. Evans, who niadc the fol- lowing record:

"Tfic specimen consists of a myomatous uterus which has l)ccu opened (apparently in a midhne anterior incision) so as to disclose an abundant deciduous endometrium thrown into large folds. At the upper posterior surface of the uterus an oval mass, about 251)y 20 by 20 mm., projects. It is a sjic and is covered with a rather smooth membrane (decidua reflexa), beneath which tortuous vessels are apparent. On one side the sac (tlie implanted chorion) is adherent to the uterine mucosa (decitlua vera). With a sharp .«cali)el the entire mass was dissected away fiom the uterus and brought under a iiinocular microscope in warm salt solution. The middle poitionof the free surface was o])cned carefully, beautiful villi being found, and then the delicate wall of the chorion was divided. Within, a transparent young embryo and its umbilical vesicle were seen, the embryo ajiiiearing to be about 5 mm. in length. Through this opening in the chorion, warm (40° C.) saturated aciueous solution of HgCl;, containing o per cent glacial acetic acid, was gently introduced and the entire mass placed in .500 c.c. of this fixation fluid. The main body of the uterus was dissected from the mj-omatous nodule andfixe<l in 10 per cent formalin, the site of the imjilanted ovum being marked by a short wooden rod."

The fixed and hardened specimen had undergone a readily appreciable shrinkage from the condition seen in warm salt solution. All of the tis.sues were beautifully preserved. The implanted ovum, covered with the decidua capsularis, measures approximately 22 by 18 by 11 mm. The adjacent decidua parietalis is thrown into large folds, which are themselves marked by numerous tiny elongated crack-like depressions, as well as by more circular pit-like apertures. The relatively smooth but irregular surface of the decidua capsularis is marked here and there by very consi)icuous, small, oval pits, which may attain 0.5 mm. in diameter. The four f1a|)s f»f this coat at its highest point, where it was oi)ened dir(>ctly over the middle of the ovum, an; rather smooth on their iimer surface an'H stand ai)art from the subjacent chorionic villi (intervillous space) to which they were originally adherent. Tlie villi are about 2.5 mm. in length and possess one or two large branches and many ".stub-like" tiny bulbous ones on the main stem. The villi are imiformly distributed in the small area exposed. With a slender .scalpel the ovum was care- fully divided under the dissecting micro.scope, the embryo and yolk-sac being visible. TIk' yolk-sac appears to be almost 2 cm. in diameter and the embryo is surroimded by its amnion, its head (visible from above) being about 3 cm. in length and showing the fourth ventricle covered by a transparent ependyma. Two gill-arches are visible. The yolk-sac surface presents an exquisite picture of irregidar. clear va.s- cular channels tuid a uniform p.itfern of small, opa(|ue. white blood-islands. The ])re.servation seenis perfect.


After the embryo had been carefully removed, the ovum was cut into blocks which included its implantation. A block 1 mm. thick, which included the largest circumference of the embrj'o, was embedded in celloidin, the sections being stained in various waj^s. A photograph of this block is represented in plate 1, figure 4, which shows strikingly the extent of the magma. Sections which have been stained in hematoxylin and aurantia show the magma much as it appears in the other embryos that have just been considered. There is a denser magma just under the chorionic wall, and heavy strands radiate in every direction, with a fine network resembling spider-web, among the main strands. A number of loose nuclei accom- pany these strands, but they do not have the appearance of the nuclei of the main wall of the chorion. They are mostly round and are of unecjual thickness, simulating very much the blood-cells. Occasionally there is a large nucleus. Sections which have been treated by the Weigert fibrin method do not show these fibrils. This confirms a previous experience which I have published elsewhere in my paper on monsters, namelj'^, that magma fibrils do not give the reaction of fibrin, nor do these fibrils stain well in Van Gieson's mixture; however, they take on color similar to the mesenchj'me of the chorion.

At points it appears as though these fibrils arise dhectl}' from the chorionic wall. Thej^ stain intensely blue by the ^lallorj^ method, and in sections treated in this way the nuclei of the mesenchyme of the vilU look much like the accompanj'^ing nuclei of the magma fibrils. On one side of the ovum a denser mass of the magma is directly continuous with the mesenchyme of the chorionic wall. However, just in this region the magma contams no nuclei. It, therefore, appears that the magma fibrils must be associated, at least partly, with the nuclei of the chorionic wall. Exceedmgly good histological pictures were obtained from sections stained by Heidenhain's method, which show all the transition stages between magma con- taining no nuclei and magma very rich in nuclei. It would seem that there is quite a free wandering of the nuclei along the magma fibrils, and whenever they come in contact with the chorionic wall the fibrils enter it, showing direct continuity. The most instructive specimens are obtained by the Weigert elastic-tissue stain, which gives a sUght blue-black tinge to the mesenchj^me fibrils of the chorionic wall, as well as to those of the centers of some of the villi. The magma itself takes on a very light stain, but where it is in contact with the chorionic wall it grades over into its blue network. It appears, then, that the centers of the villi, which represent their older portion, stain somewhat with elastic-tissue stain; and, if we view the chorionic waU as the more differentiated portion of the chorion, we must conclude that the older mesenchyme fibrils behave more like elastic-tissue fibrils than do the j^ounger. At any rate, the magma fibrils do not take on elastic-tissue stain.

From all that has been said it is clear that the mesenchyme of the chorionic wall and the magma fibrUs are continuous and, as I have pointed out elsewhere, they together form a common syncytium. I have already demonstrated that verj' young connective tissue arises directlj' from the mesenchyme, the earlier stages of which I have designated r^s the connective-tissue syncj'tium. Towards digestive reagents the connective-tissue syncj'tium gives somewhat the reaction of j-ellow elastic tissue, just as do the mesenchyme and the magma of No. 836 when treated with Weigert's

1() urMAN MAdMA nfnicn.f: ix normal and pathoi.ooicat. devklopment.

I'la.stic-t issue stain. 1 have also shown that tho younger the connective-tissue syncytium is. tlie more ilifficult it is to digest it in jx'jjsin. Frozen sections shrink Injt little when treated with acetic acid, while white fibers become transparent. The syncytium itself is somewhat elastic, as shown by pressure upon the cover- glass over a frozen section. If treated for 2-i hours with pepsin, the fibrils disin- tegrate. They are tlierefore much more resistant to the action of pepsin than are white fibrils.

The action of pancreatin is, in a measure, the opposite of that of pepsin. \Mien the main mass of syncytium is formed by exoplasm, it digests readily in pancreatin. The more the syncytium is developed, the more resistant it is towards pancreatin. \"ery young syncytium fibrils, therefore, react towards pancreatin and jiejisin much like elastic fibers and this is confirmed in a measure, by tinctorial methods, when applied to sections of the chorion and magma, in specimen No. 836.

I have discussed the denser strands of tissue within the main mass of the magma. In the fresh state it appears that these are distinct fibrils, as shown in l)late 3, figure 2. They are, also, observed in plate 1, figure 3. It is not quite so dear that there are fibrils in the magma as shown on plate 1, figure 4. In fact, it ai)pears as though we have compartments separated by membranes, and that at the junction of several of these membranes the fibrils become denser, and therefore often appear as distinct fibers. It would be more appropriate than to state that the exoccelum is broken up into compartments the walls of which arc composed of membranes, and that where .several of the membranes come together the increased amount of tissue gives the point of juncture the appearance of fibers to the naked eyi' and under the enlarging lens.

I liavc taken great pains to follow the cells which mark the stronger bands of magma, and it is difficult to arrive at any conclusion, for, in a measure, they seem to be related to the endothelial lining of the exoccelom. In the Peters ovum the spaces near the embryo are lined by a distinct laj'er of cells, but otherwise there is no indication of endothelial lining in any other portion of the chorionic cavity, nor is there any indication of such a lining in the figures given bj' Herzog, Johnstone, Jung, or Strahl and Beneke. It would seem that what corresponds to the exocoelom of the chorion in the later stages is represented by a diffuse mass in the specimen of lirycc and Teacher where the nuclei are scattered through it. The mode of the destruction of the mesenchyme is well indicated in figures on page 18 of a monograph by Strahl and Beneke. These irregular cells are first of all attached to the heavier strands of magma, and they must, therefore, correspond to the endothelial lining of (he exoca'lom. For the present, however, it appears as if the exoccrlom of the human chorion is lined only in part by a layer of endothelium; these cells nccomi)any the magma fibers and line the inner side of the chorion near the embrj'^o.

As tlie amnion expands, it naturallj^ j)ushes these strands of magma up against the chorion, and in a short time we can recognize only a few fibrils in the exocoelom whicli encircle the uml>ilical cord. are well seen in si)ecimen Xo. 14S, and their remnants are .shown in Xo.'jTO, of which I give an illustration on plate 2, figure 2. Xo. 14S is vmdoubtedly normal, for it was obtained by mechanical nieans. and Xo. .')7fi is also a normal spccinu-n obtained from a pregnancy.

The conclusion regarding the condition of the magma of normal development is that the cavitj^ of the ovum is filled with delicate fibrils which are intorpersed with numerous nuclei and which form one continuous network, extending from the embryo to the chorionic wall, and blending with its connective-tissue network. It forms one continuous syncytium, and as the ovum grows the magma reticule differentiates .somewhat. Stronger bands of membranes soon form, breaking the cavity of the chorion into compartments. This process continues until the amnion begins to expand, and then these fibrils are pushed up against the chorionic wall. The exococlom begins as two larger spaces near the embryo, and in this portion of the ovum its cavity is lined with a layer of endothelium. It is quite certain that this sharply defined cavity does not extend to include the whole cavity of the ovum, but the cells lining it arise in common with those which accompany the magma fibrils. The exact extent and the fate of the two small spaces near the embryo in the Peters specimen is still undetermined, but Waterston's specimen indicates that they do not extend to fill the entire chorionic cavity. The examination of numerous specimens, however, indicates very definitely that the exocoelom of the ovum at 2 months does not contain a complete endothelial lining.


Since the publications by Giacomini it has become well known that an increased quantity of magma within the coelom indicates with certaintj' that the embrj'o is pathological. When the magma is pictured or described, it is quite easj'- to deter- mine whether or not the embryos and ova published in the literature are normal or pathological. This is demonstrated in the plates accompanying Yelpeau's work. His was able to separate most of the normal from the pathological embryos, but he relied mainly upon the external form of the specimens, which he compared with other mammalian embryos. Unless an embrj'o appeared much like those of other mammals and was not transparent and sharply defined, he decided that it was not normal but pathological. The work of Hochstetter, who Kmited his studj' to embryos obtained through hysterectomy, has been used to advantage by Keibel and Else in the preparation of their Normentafel, so that now we have adequate tables and plates which enable us to recognize with considerable certainty whether or not an embryo is normal, without paying much attention to the magma or the chorion. However, embrj^ologists are well aware that they can predict whether a specimen is normal or pathological by the quantity of the magma which masks the embryo when the ovum is opened.

By the contents of the exocoelom it is quite easj' to classify pathological ova into three chief groups. In the first group, which includes most pathological specimens, the magma is changed into an organized mass of reticular fibrils, inter- mingled more or less with granular substance.

To the second group belong specimens in which the exoccelom is large and contains only a fluid mass — that is, a liquid substance which does not coagulate in either formalin or alcohol. I have pictured a number of specimens of this sort in my paper on monsters. Specimen No. 512, of which I give an illustration on plate 2. figure 1, belongs to this group. The embryo is atrophic, and it is questionable whether or not if is oiicircled l)y tlic amnion. In these specimens the ocrlom is usually enlarged and sometimes it is greatly distended. Often there is a small gran- ular precipitate in older specimens, but this is not of sufficient (juantity or density to form a continuous mass. The histories of these specimens show that they are consideral)ly older than their sizes indicate, and I am inclined to view them as having once had a dense mass of magma within the coelom, which subsequently underwent dissolution, leaving a more or less flaky deposit that finally disajiijearcd altogether.

In the third group, the coelom is greatly distended, the ainiiioii is usually absent, aiul the ovum is tilled with a gelatinous substance. This is well illustrated by speci- men No. 604, plate 1, figures 1 and 2.

Table 2.— List of specimens containing pathological magma

Cat No.


of ciiibrj'o.

Dimensions of chorion.

Men- strual age.

Contents of osTim. '

Cat. No.


of embryo.

Dimensions of chorion.

Men- strual age.

Contents of ovum.

278 660 813

78 531 250

12 318 543


244 402 122 533 545 21 560 135


1 1.5

2.1 2 5 3 3 4

4 5 5 5 5

5.5 • 7 9







41 42

42 65 50 53


. 1




10 [10.5]


12 14 14

17 17 20 22 25 33 57 90

mm. 30X27X18 28X28X22 45 X40 X25 35X35X15

days. 56 35


14 91

No magma.

Granular-hyaline ; also no magma.

Hyaline magma. Granular; hyaline also.

Hyaline magma.

Granular; hyaline.

Do. Do.

40 X35 X30 80 X50 X25 36X33X13 19X19X19 10 X 9X 8 18X18X 8 20X18X11 70 X30 X25 35 X30 X30 25X15X15 40 X25 X20 20X16X 6 35X30X30 12 X 9X 9 12X 9X 5

636 Hyaline magnia. 005 Fluid. 1 104 Flaky.

1 211 1117


Granular. Fluid.



991 604

94 1189 584a

79 230 261



50X50X50 50 X42 X40 50X50X50 75X60X50 120X70X70


Hyaline magnia.

I will now review several specimens illustrating these three varieties of patho- logical magma. The specimens considered are arranged in table 2. The list could easily be increased to several hundred, but as the specimens with catalogue numbers less than 403 have been iiublished in detail with illustrations in my monograi)h cm monsters, I will allude only to some of them. The pathological specimens with numbers over 402 are being prepared for publication, so that a few selected speci- mens with higher numbers are illustrated. Pathological sjiecimens from tubal preg- nancy with numbers u]) to 1,000 will be found described in detail in my monograph on tubal pregnancy.

The first specimen which 1 shall consider (No. 278) consists of an entire ovum, measuring 6 by 4 mm. It was sent me by Dr. Stanton, of Albany, New York. The specimen might be viewed as normal, but it contains no embryo, and as it was obtained from a diseased uterus, it is probably pathological, the magnia having undergone minor changes.

This ovum was found accidentally in curct lings fnmi a woman .supposed to have chronic endometritis following pregnancy. There is nothing in the history from ul,;,l, ti„. a^e of the specimen could be estimated. Part of the specimen had been cut into sections before it was received at the laboratory, with the statement that no embryo had been found, it having faUen out. I found that the half sent con- tained a coelom, 3 by 2.5 mm., filled with magma, in which there was a cavity about 1.5 by 1 mm. 1^'ections showed that the cavity was natural and not sharply defined, with nothing to indicate that it had contained an embryo. On the contrary, it was found that the magma reticule was composed of a loose network of mesoderm cells, which bound one side of the chorion with the other. These cells are directly continuous with those of the mesoderm and resemble them in every particular. At one point there is a small grouj) of epithelial cells, which may represent what was originally the embryo. Otherwise, the chorion and its villi are normal in appear- ance, being encapsulated in decidua which has in it some uterine glands. All in all, this specimen reminds one very much of the Peters ovum. There are some leuco- cytes in the decidua, but no accumulation of them indicating inflammation of the uterus. Several figures, illustrating this specimen, may be found in my monograph on monsters.

Specimen Xo. 531 is in many respects similar to the one just described ( Xo. 278 ) . It came from a woman who had been pregnant 6 times, her periods having been 17 days overdue before this abortion. The ovum is spherical, 19 mm. in diameter, and is covered only by a mass of villi which appear normal. The ccclom within con- tains many magma fibrils, the meshes of which arc more or less filled with dense granules, as is i^hown in plate 1, figure 8. Within this mass there is a detached vesicle, 1.5 mm. in diameter, which no doubt represents the umbilical vesicle.

A specimen intermediate between the two just described is X'o. 250, of which several illustrations are published in my paper on monsters. The specimen came embedded in a mass of decidua and was obtained by scraping the uterus. When opened it was found filled with magma reticule just beneath the chorion, in which could be seen a small embryo, and farther away towards the center of the coelom was the umbilical vesicle. The whole ovum was cut hito sections. The chorion and the villi are apparently normal in shape and structure, being also rich in blood- vessels, which are filled with embryo blood. The villi are bathed in mother's blood and covered with an active trophoblast. The decidua is somewhat infil- trated with leucocytes, but there are no abscesses. The front end of the amnion is absent, and its free edge and the embryo are embedded in reticular magma, indicat- ing that the amnion was destroyed before the abortion took place. The general shape of the embryo and its degree of development are practically normal. The heart is well formed and, including the blood-vessels, is filled with blood. The ali- mentary canal, brain, spinal cord, otic and eye vesicles, myotomes, and branchial arches are much like those of embryo Xo. 12, to be described presently. The septum transversum is well marked and the thyroid gland is just beginning. The tissues of the embryo, however, and the cavity of the front end of the brain are filled with numerous small round cells with fragmented nuclei. All stages of frag- mentation are seen, just as may be observed in the leucocytes in small abscesses. IMost of the red blood-cells are within the blood-vessels, but those within the tissues appear perfectly normal. On account of the dimmished number of mesoderm cells, which, in fact, diminish in proportion as the fragmented cells increase, the conclusion must bo drawn tliat the fragmented cells arise from the mesoderm cells. Tlie ei)idormis covers the whole embryo. The primary change in this specimen is no doubt in the mesoderm, for all the rest of the embryo appears normal. That the c(|uililM-ium was overthrown is indicated by the necrotic amnion and the great amount of reticular magma in the exoccrlom. \\'hat is especially interesting in this specimen is the partial destruction of the amnion, which brings the embryo directly in contact with the pathological magma of the coelom.

Embryo Xo. 12, which has been just referred to, may also be discussed in this connection. It was questionable for a long time whether or not the eml)ryo was normal, as the villi and contents of the ccelom and embryo are beautifully preserved and show no pathological change. However, more careful consideration of the specimen shows that there are a few fibrinous masses between the villi, with every indication of uterine inflammation and infection. The extent of the reticular magma is more pronounced than usual, and it w'as necessary to dis.sect it away before the embryo could Ije isolated sufficiently so that it could be well seen. The head is no doubt atrophic, and I am fully convinced that this part of the embryo must have undergone pathological changes a short time before the abortion.

Specimen Xo. 318 is much Uke X"o. 250. The ovum, measuring 20 by 18 b.\- 1 1 mm., is covered with villi which appear to be perfectly normal. Upon opening, it was found to be filled with stringy magma, on one side of which was embedded an embryo 2.5 mm. in length. The head is sharply outlined, but the embryo seems to continue directly with the uml)ilical vesicle, leaving an atrophic tail. Sections .show' that the amnion over the head has dissolved, leaving a picture very much like that shown in Xo. 250. ^^'e ha\e here a small embryo with a very large ca?lom, the ovum being moderately filled with reticular magma and a small embrj'o only partlj' covered with the amnion. Xo. 543 is another embryo of the same type. The magma is a little den.ser than in Xo. 318. The chorionic villi are developed, but markedly pathological, as the photograph show^s. The embryo within is 3 nmi. long, lying (juite free within the mass of magma. It is covered by a ragged anmion; that is, the amnion is jjartly destroyed.

An interesting specimen in this connection is X"o. 402, which is partly described in my paper on monsters, since the issue of which the embryo and chorion have been cut into serial sections. The villi of the ovum are not well developed, and they are distributed irregularly over the surface. The coelom is filled with reticular magma. The embryo is club-shaped, the head being much too far advanced for the body. The umbilical vesicle is normal in .size; the heart is well outlined, and the extremities are just api)earing. Sections .show that the amnion is greatly distended. Sections of the chorion were stained with cochineal and ^'an (iieson, and show beautifully the fibrillated structure of the chorionic membrane. These fibers take im red stain, as do thoseof the reticular magma. The two are continuous, as .shown by the illustration on plate 3, figure 3. In fact, this continuity is much more pronounced in i)athological than in normal specimetis.

Specimen Xo. 533 (plate 2, figure 3) .shows a more atlvanced stage ol an extensive development of reticular magma. The villi of the ovum appear to be norinal and tl,,. iLiioular magma is very dense. Hehveeii tlie meshes there are a number of opaque nodules about 0.5 mm. in diameter. \\ illi much difficult^' the embrj'o was teased out, but it was practically impossible to clear it entirely of the magma fibrils. The embryo is long and slender, looking more like that of a dog than a human speci- men, the head being unusually small and thin for a human embryo of 0.5 mm. long. The fibers are irregularly^ stuck together by small granules, and there is a gap in the center which represents the place in which the embrj'o was located. The illustration shows this condition beautifully. The specimen was sent me bj' Dr. Fewsmith, of Trenton, New Jersey, who obtained it from a woman whose menstrual period had been a month overdue.

An extremely interesting specimen is Xo. 545, well illustrated in figure 1, plate 3. The magma is not extensive, but it is pronounced. The embrj'o is atrophic, and the chorion is only partly covered with vilU. The specimen was sent me by Dr. Rand, of New Haven, Connecticut. It was obtained from a woman who is the mother of one healthy child. The last menstrual period began on September 2. Bleeding began on October 22 and ended with the abortion on October 25. The ovum was found embedded in the clots of blood attached to the cervix of the uterus.

An extreme case of degeneration of the magma is sho^Mi in No. 660, also well illustrated in figures 4 and 5, plate 3. There is a tendency towards membrane formation, tough strands of fibrils, spaces, and clumps of granules. The chorionic wall is hemorrhagic and degenerated; within there is a collapsed amnion containing a cheesy granular mass.

I shall use two more specimens to illustrate the nature of granular mass in more advanced stages. The first is No. 605 and the second is No. 584a. No. 605 is a white transparent specimen, covered with a uniform laj'er of \'\\\i which branch two or three times. The entire specimen measures 45 by 40 by 25 mm. ; a small patch of decidua adheres to the outside. The interior is partly filled with coarse strands of reticular magma, having numerous granules attached. On one side of the specimen the umbilical cord is seen, surrounded b}- a ragged amnion. The tip of the cord has a piece of intestine and stomach hanging from it. The larger masses of tissue which are intermingled with the reticular magma must be the renmants of the embryo, parts of which appear to be normal, and judging from the form and size of the arms and legs the embryo is about 10.5 mm. long. The second specimen is unusually interesting because it contains a normal embryo with hernia of the Uver. The exoccelom is unusually large and is filled with a more extensive layer of reticular magma than should be found in an ovum containing a normal embrj^o of this size.

The remaining three si)ecimens are given because they well illustrate various degrees of reticular magma within the ovum.

No. 560 (plate 1, figure 6) shows very pronounced reticular magma intermingled with much granidar. Two stages of somewhat later development are given in Nos. 636 and 991. In the former (plate 1, figure 10) the magma is more pronounced than in normal development, and in the latter (plate 1, figure 7) it is in an extreme amount.

Finally, a unique specimen (No. 1189) throws some light upon the formation of the reticular magma. The ovum came to us within the uterus, having been removed by an operation. At first it seemed to be normal, but on opening it the embryo was found encircled by a large mass of transparent, tough, stringy reticular magma, which was removed only with great difficulty. It behaved much like the vitreous humor of the eye. On account of its great (juantity we at once suspected that the sju'cimen was pathological, and after the embryo was removed it proved to i)e so. Ahhough (juite advanced in development, its head was found to be smaller than normal, the tissues of the face were dissociated, and the borders of the eye were not sharp but ragged. No doubt the specimen had continued to develoi) normally until shortly before the operation, and the magma increased in quantity and became tough and fibrous. It is an interesting specimen, showing changes in the magma late in di'velopment. Sections of the implanted ovum have not .yet been made. The specimen is from a negress, 45 years of age, who had had 9 previous jjregnaii- cies. Her last menstrual jjeriod was 67 days before the operation. Pregnancy was suspected before the removal of the uterus, but a hysterectomy was performed because her periods had become verj' severe, lasting 8 days and causing faint ness and weakness.

The two types of degeneration which the reticular magma undergoes have been considered above. The magma becomes granular and denser as it lessens and be- comes li(|uid. The liquid again either coagulates or remains fluid when the speci- men is fixed in formalin. The two fluid types maj' be related to the destruction of the amnion, but as yet I have been unable to reach a conclusion regarding this point.

The beginning of the formation of granular magma is shown in specimens No. otJO and 991 (plate 1, figures 6 and 7) as well as in Xos. 533 (plate 2, figure 3) and 6G0 ( plate 3, figure 5) . It appears to extend into the cavity of the amnion, and often forms great crusts, which surrovmd the embr3'o, as shown in several siiecimens l)ictured in my monograjjh on monsters (e. g., Xos. 79, 94, 104, 230, and 261). An extreme sj)ecimen of granular magma w'ithin the exococlom is shown in specimen Xo. 651</ (plate 1, figure 9).

It is extremely difficult to determine with certainty the structure of the granular magma, but in studying pathological ova (especially those obtained from tul)al preg- nancy) I have fre(|uentiy ol)served that there are large masses of granular magma which take on hematijxylin stain. The.^^e granules are mixed with a slimy mass which takes on hemat<jxylin stain. My attention was called to granules they have a characteristic circular stratification and contain within their centers small granules which also stain intensely. 1 am by no means certain whether all granular magma stains in this way with hematoxylin, and what T have just stated may apply only to a portion of the granular magma.

Specimen Xo. 531 (siiowii in figure 8, i)late 1) has its ccrlom filled with a li(iuid in which there is a granular dejwsit that surrounds the embryo anlage. Such specimens are numerous and, without opening them, they may frequently be recog- nized by the transparency of the chorionic wall, which is covered with but few atroi)hic villi. A more advanced embryo, showing the same condition, is shown in specimen Xo. 512. In it the embryo is atrojihic and macerated, without the l)iesence of an amnion. The chorion is thin and is fully covered with delicate degen- erati'd villi. (Jther specimens which come within this group are Xos. 21, 7S. 122, and 244f/. are all illustrated in my monograph on monsters.

Sometimes the entire specimen is filled with a gelatinous mass, which becomes firmer when fixed in formalin and separates into a more sohd mass, and into a liquid when preserved in formalin. This mass appears to lie within the amnion in most specimens, as in cases where it fills the whole ovum the amnion is missing. Speci- men Xo. G04 (plate 1 . figures 1 and 2) is (juite typical, as is Xo. 13o. In Ijoth the embryos are atr()i)hic and necrotic, and the jelly-like fluid fell out with w'hen the ovum was cut open. The chorion is atrophic in both of them and is covered only with a few atrophic villi. Specimen Xo. 604 came to me without a history, and measures 70 by 50 bj' 50 mm. It is fully covered with fibrinous clots, between which there are few large villi, as the picture shows. The chorionic wall is 3 to 4 mm. in thickness, and its interior is entirely filled with jelly-like magma of uniform consistency. On one side of the specimen, lying free witliin the hyaline magma, is a straight embryo, 17 mm. in length, with atro])hic head, arms, and legs. The same description applies equally well to Xo. 135. Specimens like these are quite numerous in our collection of human ova, but usually the jelly is lost when the speci- men is ojjened. Figures illustrating embryos of this sort maj' be .seen in mj^ paper on monsters, under the descriiition of embryos X'^os. 79, 94, 230, 261, and 270.

Xo. 1117 (plate 1, figure 5) contains an embryo well i)acked in the jelly-like magma. The cavity of the ovum is small and its wall is very hemorrhagic. The specimen came from a woman, age 26 j-ears, who was married at 15. She had two births at term and one previous abortion. She believed she became pregnant about 3 months before the operation, although she had not missed her regular periods.

Another specimen belonging to this category is X^o. 813. It consists of a fleshj' mole, well filled with tough, jelly-like magma. All the vilh are destroyed and its surface shows ulceration. Further study of this magma is necessarj' before it can be related to the granular magma which forms with the reticular magma in the exocoelom. I am inclined to believe that the hyaline substance which is so often found within the amnion of pathological specimens arises from the amniotic liquid, which has become richer in albumen, and therefore congeals into a jelly-like ma.?s when preserved in formalin.


The fibrils forming reticular magma are always in direct continuity with those of the mesenchyme of the chorionic wall. This can easily be demonstrated by means of Van Gieson stain, and reticular magma must therefore be viewed as embryonic connective tissue extending into the cavity of the ovum. The stronger strands are accompanied more or less by mesenchyme nuclei, show^ing that the magma itself must be viewed as independent connective tissue identical with the mesenchyme of the chorion. As the amnion extends these strands are pushed aside, their final remnants being seen in that portion of the exoccelom which encircles the umbihcal cord.

In pathological specimens the reticular magma increases in quantity in the earlier stages of development, continumg for a number of months of pregnancy. Frequently the meshes between the reticular fibrils are filled with pecuhar stratified granules which take on an extensive hematoxjdin stain. Often the amnion is destroyed e:irl>- in (k'veK)i)nient, in wliicli case the magniii may dissolve, but some- times it inrreases {greatly in (luantity, forming a gelatinous mass. Freciuently pathological ova are encountered in which the development of the embryo is retarded, and the amnit)n is often found filled with a flaky deposit that, as time goes on. increases greatly in quantity and finally forms large crusts which invest the embryo. In other cases there is marked hydramnios, and in certain instances, where the amnion is destroyed, the magma dissolves, leaving only the embryo floating in the fluid encircled by the chorionic wall. Specimens are also found in which the ca\ity of the amnion is greatly enlarged and is filled with a jelly-like sub- stance, which in later stages may form crusts encircling the embryo. The true relation between the ])athol()gical changes of the contents of the exocoelom and of the cavitv of the amnion remains to be determined.


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Eternod, a. C F. : La gastrulc dans la .seric animalc et plus speeialemeut ehcz I'hommc et les mammif6rcs. Tirage a part du Bull. Soc. Vaud. So. Nat., 1906, xi.ii, 150, Lausanne, 1906.

. Dea premiers stades de I'ocuf liumain et de son implanation dans I'uterus. M6moirc present^ au premier Congrfcs ffdfratif international d'anatomic (Geneve, 6-10 aout 190.5), Nancy, 1906.

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derme et placenta. Mf-moirc publi6 ii I'occasion du Jubilfi de rUniversitt, l,i.59 1909, Geneve, 1909.

. In6galit6s de croissance du chorion ovulaire humain et localisations consecutivcs en chorion laive et chorion frondosum. C R. de la Reunion de r.\s.-;ociation des Anatomistes (Nancy, 5-7 avril 1909). Lille, 1909.

Fkassi, L.; Ueber ein jungcs menschlicheaEi in situ. Archiv fiir mikroskopische Anatomic und Entwicklungs- gcschichte, Bd. 70, 1907.

GiACoMiNi, C: Probleme aus Entwickelungsanomalien d. Menschl. Embryo. Mcrkel and Bonnet "Ergeljnisse." iv, 1894.

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Ingalls, N. W.: Beschrcibung cines menschlichen Embryos von 4:9 mm. Archiv. fQr mikroskopische Anatomie und EntwicklungsKcschichte, Bd. 70, 1907. JOH.NSTONE, R. W.: Contribution to the study of the early human ovum. Journal of Obstetrics and Gync-

cologj' of the British Empire, 1914. Juno, P.: Ei-Einbettung Iieim menschlichen Weibo. Berlin,

1908. Keibel, F. : Die aussere Korpcrform von Affenembrj-oucn.

.Selenka, Entwickelungsgeschichte, xiv, Wiesbaden,

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tion problem. Kcibcl and Mall, Human Embr>--

ologj-, I, chapter v, 1911. Keidel und Elsa: Normentafel zur Entwicklungsges-

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theWistarlnstituteof Anatomy, Philadelphia, 1908. . Development from the connective tLssue of the syncytium. .Vmerican Journal of Anatomy, i, 1901. . On the fate of the human cmbrjo in tubal pregnancy. Publication No. 221, Carnegie Institution of Washington, 1915. Peters, H.: Einbcttung des menschlichen Eies. Leipzig und

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of Anatomy and Physiologj', xlix, 1914.

Explanation of Plates

Plate 1

Fl<58. I, 2. Pliotograplis of the two lialves of o\-um Xo. 604. Natural size. Tlio cavity of (lie ovum is filled with a

jelly-like substance in which a pathological embrj-o is embedded. Fig. 3. Section through a normal ovum Xo. 836, encapsulated in the decidua. X3}. Drawn by Mr. Didusch.

The embryo lies within the coelom, and bands of -magma fibrils radiate from the amnion to the chorionic

wall. The head of the embryo shines through the more transparent portion of the amnion. Fig. 4. Photograph of a block of the ovum, Xo. S36, in situ after the embryo had been removed. X25. The

.«up|)orting strands of magma are strikingly shown. Fig. 5. Pathological embrj-o Xo. 1117, embetlded in hyaline magma. X4. From a tubal pregnancy following

gonorrhea (?J. Fig. 6. Pathological o\Tim Xo. 560, containing a great quantity of reticular magma. X2i. The embrj-o is

normal in form. From a case of retroversion of the uterus. Fig. 7. Pathological ovum Xo. 991, with the cavity completely filled with reticular magma. Xatural size. The

embryo is normal inform. From a negro woman. Sect ions of the embryo indicate that it Ls macerated. Fig. S. Pathological ovum N'o. 531, containing a granular deposit around a nodular embryo. X 1 §. Fig. 9. Pathological ovum with a nodular cmbrj-o (651?). X2. The exocteloni is gorged with granular magma. Fig. 10. Specimen Xo. 636. X"2J. The embryo and chorion are normal in form, but the reticular magma is

marketlly increased in quantity.

Plate 2

Fig. 1. Pathological embryo Xo. 512, lying free within the ovum. X6. The villi are tliin and scattered and the

embryo is atrophic. There is no formed magma. Fig. 2. .\n ovum, Xo. 576, obtained from tubal pregnancy, showing a delicate layer of magma fibrils around the

attachment of the umbilical cord to the chorion. X3. Fig. 3. Ovum Xo. 533, showing ven.- extensive magma. x6.

Plate 3

Fig. 1. Ovum Xo. 545. X7. There is a delicate network of fibrils below the amnion and the chorion.

Fig. 2. Kmbryo Xo. .588. XS. Delicate strands are shown radiating from the umbilical cord and yolk-sac. This figure is given to show the appearance of magma in vesicle development. From a woman who has IukI numerous me<;hanical abortions performed upon herself. Uterus badly inflamed.

Fig. 3. Section through the chorion and magma of Xo. 402. X280. The specimen was stained with Van Gicson stain and shows that tlie fibrils of the magma are continuous witli those of the mesenchyme of the chori- onic wall. It came from a case with subinvolution and symptoms of endometritis.

Fig. 4. Outline of the ovum of Xo. 660. Xatural size. The diagram indicates the part of the specimen shown enlarged in figure 5.

Fig. 5. Xo. 060, showing ver>' extensive changes in the magma. X6. The upper tip of the amnion is shown. The magma is fibrillar and granular, and at places the fibrils seem to form membranes. The chorionic wall is very hemorrhagic.

Fi;?. 1 C604)

Fi-. 2 (604)

Fig. 3 (836) 4 (836)

lis- 5 (in?)

Fig. 6 (560)

Pig. 7 (991)

Fig. S (531)

Fig. 9 (65:-G)

Fig. 10 (636)

Fig. 3 (ysS)

Fig. 2 (55S)

Fig. 1 045)

Fig. :? (W2)