88 



TEXT-BOOK OF EMBRYOLOGY. 



Prim, pericard. 

 cavity 



Anlage . 

 of heart 



Telencephalon 



"" Diencephalon 



Mesencephalon 



Metencephalon 



Myelencephalon 



Peripheral limit 

 of coelom 



FIG. 80. Dorsal view of dog embryo with ten pairs of primitive segments. Bonnet. 



Neural Prim. Intermed. 



groove seg. cell mass 



Parietal and 

 visceral mesoderm 



Ectoderm 

 (epidermis) 



Chordal Prim, 

 plate aorta 



Coelom Entoderm Blood vessels 

 FIG. Si. Transverse section of dog embryo with ten pairs of primitive segments. Bonnet. 



