— FI(j.l5 



14 



Fig. 14 Graphic reconstruction showing the distribution of the endothelium 

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

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

 X 300. Reduced i. 



1 Mesal margin of coelom 4 .Vngiocysts of cardinal line 



2 Lateral margin of coelom ."i Somite 1 



3 .\ngiocysts of umbilical line li Somite 4 



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

 Slide 3, row 2, section 10, X300. Reduc(>d ;. 



1 Vasofactive cells 3 Coelom 



13 Aorta 



Fig. 10 Graphic reconstruction of the vessels of the somatopleure ami of a 

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

 Xo. ISS, left side, dorsal view, X 300. Reduced \. 



1 Umbilical vein 



2 Site of communication of (he um- 



bilical with th<' omphaloTiH'sen- 

 teric vein 



3 Anterior jugular \i'iii 



4 Comnumications of the anterior 



jugidar vein with the juxhi-neural 

 anastomosis 



5 Communication between the aorta 



and the umbilical vein 

 (i Aorta 



7 Isolated angiocysts 

 S Somite 1 

 !» Somite 1 



70 



