3:> 



^6 



JORDAN. 



REFERENCE LETTERS. 



nd. 

 n.f. 

 n.g. 

 np. 



prg. 

 prs. 

 sp. 



y- 



y.p. 



Notochord. 

 Neural folds. 

 Neural groove. 

 Neuropore. 

 Primitive groove. 

 Primitive streak. 

 Spermatozoon. 

 Yolk. 

 Yolk-plug. 



y. spfi. Yolk spherules. 



