Paper - The early development of the cat

From Embryology
Embryology - 14 Dec 2019    Facebook link Pinterest link Twitter link  Expand to Translate  
Google Translate - select your language from the list shown below (this will open a new external page)

العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt    These external translations are automated and may not be accurate. (More? About Translations)

Hill JP. and Tribe M. The early development of the cat (Felis domestica). (1924) Quart. J. Microsc. Sci., 68: 513-602.

1924 Cat Development: 1. Ovum of the Cat | 2. Process of Cleavage | 3. Formation of the Blastocyst | 4. Discussion | Plates | cat
Online Editor  
Mark Hill.jpg
This historic 1924 paper describes cat development.


Cat Development

James Peter Hill
James Peter Hill

The early development of the cat (Felis domestica)

Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic Textbook" and "Historic Embryology" appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms and interpretations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Contents

Introduction

Material And Methods

Chapter I.—The Ovum Of The Cat

  1. Maturation and Ovulation
  2. Structure of the Ovum
  3. Fertilization
  4. Remarks on Fertilization

Chapter II.—The Process Of Cleavage

  1. Description of Cleavage
  2. Remarks on Cleavage
  3. Yolk-elimination (Deutoplastnolysis) .

Chapter III.—Formation Of The Blastocyst

  1. Late Morula and Early Blastocyst Stages from the Uterus
  2. Formation of the Didermic Blastocyst

Chapter IV.—Discussion

  1. Mode of Formation of the Blastocyst
  2. History of Embryonal Knot and Covering Trophoblast
  3. Prochordal Plate

List Of References

Explanation Of Plates

Introduction

Our knowledge of the early development of the Cat, as indeed of the Carnivora in general, is singularly incomplete. Th. L. W. Bischoff, in his classical monograph ' Entwicklungs- geschichte des Hunde-Eies ' published in 1845, provided the first account of the development of a Carnivore from the unsegmented egg onwards and, considering the date of his work, his achievement was really a remarkable one. In addition to later embryonic stages, he described and figured a series of segmenting ova and blastocysts of the Dog, with such fidelity and accuracy that his account is, even today, of the greatest interest and value. He recognized and figured the germinal vesicle of the full-grown ovarian ovum and the refractive granules (' Dotter ') present in the cytoplasm of the latter. He observed the persistence of part of the discus proligerus round the unsegmented tubal egg, and noted its thick zona and the numerous sperm-heads imbedded in it. He figured the two-celled egg with what are evidently two polar bodies situated in the plane of cleavage. He described and figured the three-celled and four-celled stages, his figures of the latter showing quite accurately the characteristic cross- shaped arrangement of the blastomeres. He figured three later tubal eggs, said to be composed of eight, ten, and eighteen blastomeres respectively, and he also illustrated and described a series of morulae and blastocysts from the uterus. He recognized the delicate membranous wall of the blastocyst lying inside the zona and also ' den runden und gleichmassig dunkeln Fruchthof ', and since he found that the latter is situated in the former, he termed this vesicular stage ' die Keimblase '.


No further contribution to our knowledge of early Carnivore development appears to have been made until 1876. In that year E. A. Schafer (now Sir E. Sharpey Schafer) gave an account (45) of the structure of blastocysts of the Cat, possessing a bilaminar embryonal area, one-sixtieth of an inch (0-4 mm.) in diameter. In 1897 Bonnet (14), in his paper on the development of the Dog, described and figured (his figs. 1-3, Taf. 80-1) three eggs of the Cat, one unfertilized, a second with two pronuclei, and a third divided into nine blastomeres of unequal size. He obtained no early material of the Dog, and begins his description of the development with blastocysts 1-5x1-2 mm. in diameter.


In 1911 there appeared a valuable paper by R. van der Stricht (55) entitled ' Vitellogenese dans l'ovule de chatte '. This paper, as is indicated by the title, is primarily concerned with providing a detailed account of the growth of the ovarian ovum, including the process of vitellogenesis in the Cat, but it also includes most valuable chapters dealing with matura- tion, fertilization, and the early stages of cleavage, though the cleavage process is not followed in detail beyond the three- celled stage. It also contains important data relating to breeding habits, oestrus, and ovulation.


In the same year there appeared yet another paper, that of W. H. Longley (37), likewise dealing with the phenomena of maturation and ovulation, the structure of the ovum and the first cleavage division in the Cat.


The most recent contribution to our knowledge of Carnivore development we owe to 0. van der Stricht. In two papers (53, 54), published in 1923, he has described the structure of a series of blastocysts of the Dog ranging from 0-20 to 1-5 mm. in diameter, and has traced the history of the inner cell-mass. His observations, which are referred to later, whilst agreeing in most respects with our own, show that there are certain very interesting differences in the details of the differentiation of the inner cell-mass in the two forms. We are greatly indebted to Professor van der Stricht for affording us the opportunity of examining his preparations of these blastocysts and also of earlier rnorula stages which he has not yet described.


We desire to express our thanks to Mr. F. J. Pittock for invaluable help in the preparation of the material, the micro- photographs and models, to Mr. T. L. Poulton for the drawings of the models represented in Text-figs. 1-8, to Miss M. Rhodes for figs. 5-9 (PI. 25), and to Mr. W. Pilgrim for figs. 1-4 (PI. 24). To the Government Grant Committee of the Boyal Society we are indebted for grants in aid of our work.

Material and Methods

The material which forms the basis of this paper has all been obtained from cats of unknown origin, which came into our hands shortly after death. Its collection was begun in 1909, with the object primarily of obtaining demonstration material for teaching purposes, and has involved the examination of some hundreds of females, only a small proportion of which yielded early stages. We have rejected for the purposes of this paper all eggs which appeared abnormal or whose state of preservation was unsatisfactory. The material that remains forms a fairly graded series extending from the fertilized egg through early and late cleavage stages up to the completed blastocyst in which the definitive embryonal area is established. Although our material, more especially of the early cleavage stages, is not abundant enough to enable us to settle con- clusively certain problems, e. g. the significance of the ' corps enigmatique ', and the very interesting question of the lineage of the central cells which furnish the embryonal knot of the early blastocyst, it is nevertheless sufficiently complete to enable us to give what we hope is a fairly adequate account of the cleavage process and the formation of the blastocyst and its constituent layers in Felis, and thus to provide for the first time a connected account based on modern methods of the early ontogeny of a Carnivore.


Owing to the convoluted character of the Fallopian tubes, their small diameter and relatively thick walls, the Cat is not altogether an ideal subject from which to obtain cleavage stages. In cases where the condition of the corpora lutea and the absence of uterine swellings indicated the presence of eggs in the tubes, our normal procedure was to dissect away the folds of the peritoneum supporting the tube so as to enable the latter to be straightened out. It was then cut through, close to its entrance to the uterus, and perfused with the fixing fluid by means of a pipette provided with a strong rubber bulb. In this way the ova were washed out into a crystal dish, and were afterwards searched for under the higher powers of a Zeiss—Greenough binocular microscope. We have also employed the method advocated by R. van der Stricht and other workers (cf. Longley, p. 143) of expressing the contents of the straightened-out tube on to a slide, by firmly stroking the tube (preferably cut into two or more segments) along its length with the back of a scalpel. We regard this as a very useful method.


As fixatives we have employed the fluids of Plemming and Hermann as well as picro-nitro-osmic acid, with satisfactory results. In order to prevent loss during imbedding, we fastened each egg to a thin slice of brain-cortex by means of a thin solution of photoxylin (0.5 to 1 per cent.). Sections were cut by the Minot rotary microtome, mostly at 6 µm, and were stained with Heidenhain's iron haematoxylin.


We have prepared wax-plate models of a number of cleavage stages, which are illustrated in Text-figs. 1-8. These have proved invaluable more especially in tracing out the lineage of the central cells of the morula from which the embryonal knot is derived, and in demonstrating the occurrence of a process of overgrowth or epiboly, whereby the central cells come to be completely enclosed by the future trophoblastie cells.

Migration of Eggs

In view of recent observations (cf. Corner, 19) on the migration of ova from one uterus into the other in the Pig, we take this opportunity of recording a case in a cat which came under our notice in collecting the material described in this paper. In this particular cat (9.9.5.12) one ovary showed no visible corpora lutea, but the related uterus possessed two uterine swellings, one low down at the junction of the uterus Avith the vagina and the other higher up. The former swelling contained an abnormal embryo, the latter a normal one. The other ovary showed three or four corpora lutea, and the uterus a single uterine swelling. We think this case affords strong presumptive evidence of migration.

Duplication of Uterine Lumen

We also venture to record here an interesting case of duplication of the uterine lumen. In Cat 27.1.10 one of the uteri possessed two lumina, which commenced close to its upper extremity and con- tinued through its entire length quite separate and distinct and at its lower end opened by separate openings into the


Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic Textbook" and "Historic Embryology" appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms and interpretations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)
1924 Cat Development: 1. Ovum of the Cat | 2. Process of Cleavage | 3. Formation of the Blastocyst | 4. Discussion | Plates | cat

Reference

Hill, J. P., and Tribe, M. 1924. The early development of the cat (Felis domestica). Quart. J. Microsc. Sci, 68, 513-602.



Cite this page: Hill, M.A. (2019, December 14) Embryology Paper - The early development of the cat. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Paper_-_The_early_development_of_the_cat

What Links Here?
© Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G