94 



GENERAL ANATOMY. 



Fig. 54.' 



2 



8 



Diagrams to show the development of the three blastodermic layers on antero-posterior sections. A. por- 

 tion of ovum with the vitelline membrane and germinal area. B C D E F. Various stages of development. 

 G. Ovum in the uterus and formation of decidua. 1. Vitelline membrane. 2. External blastodermic layer. 

 2'. Vesicula serosa. 3. Middle blastodermic layer. 4. Internal layer. 5. Vestige of the future embryo. 

 6. Cephalic flexure of the amnion. 7. Caudal flexure. 8. Spot where the amnion and vesicula serosa are 

 continuous. 8'. Posterior umbilicus. 9. Cardiac cavity. 10. External fibrous layer of the umbilical vesicle. 

 11. External fibrous layer of the amnion. 12. Internal layer of the blastoderm forming the intestine. 13. 

 14. External layer of the allantois, extending to the inner surface of the vesicula serosa. 15. The same now 

 completely applied to the inner surface of the vesicula serosa. 16. Umbilical cord. 17. Umbilical vessel?. 

 18. Amnion. 19. Chorion. 20. Foetal placenta. 21. Mucous membrane of uterus. 22. Maternal pla- 

 centa. 23. Decidua reflexa. 24. Muscular wnll of uterus. 



The same note applies to this as to the preceding diagram. 



