:\/ 











'•^^ 



Fig. 57.— Surface view of an embryo of 52 hours. (After 

 Duval.) 



Aam, vitelline artery. C, heart, FO, olfactory pit. LC, lateral limits of 

 body. A' C, tail. K^, mid-brain. Fz/^ and KwA anterior and posterior branches 

 of the vitelline vein. Kfj, eye. 



