7 — A — the same as Fig. 6A; the serous layer begins the 

 formation of the amnion at the head (/) and tail 

 (g) ends; B — i — the posterior end of the umbilicus; 

 g — posterior end of the tail folds of the amnion; 

 h — sac of the chorion; 



8 — later fetus; a— heart, transition into the vascular layer dd; 

 bb — intestine, connected by means of the yolk — 

 intestinal duct (which corresponds with the wide 

 previous opening Kk-) with the amnious layer QQ , from 

 which it is formed (79) ; gh — the gradually closing 

 amnion; 



9 — still later stage; all the previous designations; 



between the intestine and the body of the embryo 

 is the mesentery. 



269 



