336 



THE DEVELOPMENT OF THE CHICK 



Fig. 193. — Reconstruction of the septum trans versum and 

 associated mesenteries of a chick embryo of 5 to 6 days. (After 

 Ravn.) 



A. Entire. 



B. After removal of the hver and sinus venosus. 



A., Aorta, ac. M., Accessory mesentery. cav. F., Caval 

 fold. coel. F., Cccliac fold. Her., Hiatus communis reces- 

 sum. Int., Intestine. Lg., Lung. Liv., Liver, m. p., Pleuro- 

 pericardial membrane, pvl., Primary ventral ligament of the 

 liver. Sv., Sinus venosus. 



mesentery), uniting the ventral and posterior face of the liver 



to the body-wall just in front of the umbilicus (Fig. 193 A, pvl.)- 



For the purposes of these figures the body-wall is cut away. 



Nevertheless, it can be seen that the pericardial cavity communi- 



