GENERAL ANATOMY. 

 Fig. 53.' 



Diagrams to show the development of the three layers of the blnstodermic membrane on transverse sec- 

 tions. A. Portion of the ovum with the zona pellucida and the germinal area. B C D E F Q. Different 

 singes of development, o. Umbilical vesicle, a. Aninion. '. Intestine, p. Peritoneal cavity. 1. Vitelline 

 membrane. 2. External bloModermic layer. 3. Middle layer. 4. Internal Inyer. 5. Medullary laminaa 

 and groove. 5'. Medullary canal. 6. Epidermic laminae. 7. Lateral flexures of the amniun. 7'. The 

 same almost in contact. 8. Internal epithelial layer of the aninion. 9. Epidermis of the embryo. 10. 

 Chorda dorsalis. 11. Vertebral laminae. 12. Protovertebrae proper. 13. Muscular laminae. 14. Lateral 

 laminae. 15. Fibro-intestinal laminae. 16. Cutaneous lamina. 17. Internal fibrous layer of the uml>ilical 

 vesicle. 18. Muscular laminae extending to meet the cutaneous. 19. External layer *f the cutaneous 

 laminae. 20. Internal layer of the game. 21. Mesentery. 22. Fibrous layer of the intestine. 



1 The dotted linos indicate the parts belonging to the internal blastodermie. layer; tin- plain 

 lines those belonging to the middle ; the Interrupted linos those belonging to the external. 



