f FIG.15 



14 



Fig. 14 Graphic reconstruction showing the distribution of the endothelium 

 and vasofactive cells in the somatopleure of an embryo of twelve somites. The 

 cavities are shown in red. Columbia Collection No. 540, left side, dorsal view, 

 X 300. Reduced J. 



1 Mesal margin of coelom 



2 Lateral margin of coelom 



3 Angiocysts of umbilical line 



4 Angiocysts of cardinal line 



5 Somite 1 



6 Somite 4 



Fig. 15 Transverse section of same embryo at level indicated in figure 14. 

 Slide 3, row 2, section 10, X300. Reduced J. 



1 Vasofactive cells 3 Coelom 



2 Aorta 



Fig. 16 Graphic reconstruction of the vessels of the somatopleure and of a 

 portion of the aorta from an embryo of fourteen somites. Columbia Collection 

 No. 188, left side, dorsal view, X 300. Reduced i 



1 Umbilical vein 



2 Site of communication of the um- 



bilical with the omphalomesen- 

 teric vein 



3 Anterior jugular vein 



4 Communications of the anterior 



jugular vein with the juxta-neural 

 anastomosis 



5 Communication between the aorta 



and the umbilical vein 



6 Aorta 



7 Isolated angiocysts 



8 Somite 1 



9 Somite 4 



70 



