STRUCTURE OF FOUR-DAY CHICKS 



I2Q 



ductus choledochus 

 mesoncphric duct 

 dorsal mesentery 



dorsal ganglion 

 neural tub 



omphalomesenteric vein 

 ventricle 



E 



dorsal aorta 

 post, cardinal v. 



lateral telencephalic 

 vesicle 



ectoderm of head, 



dorsal mesentery 

 post, cardinal vein 



liver 

 ant. appendage bud 



coelom 



omphalomesenteric vein 

 allantoic vein 



extra-embryonic coelbm 



allantoic vesicle 



splanchnic 

 mesoderm 



dorsal 

 ganglion 

 post, cardinal v. 



dorsal aor 

 /*"!* mesonephric duct 



vitelline 

 vessels 



allantoic vein/ omphalomesenteric veins 



entoderm 



SLh ^\ 



sub- intestinal 



vein 



allantoic vein 

 allantoic stalk 



llantoic art. 

 coelom 

 post, appendage 



FIG. 46. Diagrams of transverse sections of a four-day chick. The location of 

 the sections is indicated on a small outline sketch of the entire embryo. 



