10 



COMPARATIA^E ANATOMY 



JiF- 



AI---I- 



Vui. 8, A, B, AND C— Diagrams illustrating the Formation op the Amnion, 

 Allantois, and Yolk-Sac. a and B, in Longitudinal Section ; C, in 

 Transverse Section. 



J£, embryo ; Dli, alimentary cavity ; Do, yolk-sac ; +, vitello-intestinal duct ; PP, 

 o<^-lome ; All, amniotic cavity ; AF, amniotic fold ; A, amnion ; Al, allantois ; 

 n, somatopleure : h, splanchnopleure ; M, medullary cord; C, notochord. 



