336 THE DEVELOPMENT OF. THE CHICK 
Fia. 193. — Reconstruction of the septum transversum and asso- 
ciated mesenteries of a chick embryo of 5 to 6 days. (After 
Ravn.) 
A. Entire. 
B. After removal of the liver. 
A., Aorta. ac. M., Accessory mesentery. cav. F., Caval 
fold. ecoel. F., Ccaehae fold. Her., Hiatus communis reces- 
sum. Int., Intestine. Lg., Lung. Liv., Liver. 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.). 
lor the purposes of these figures the body-wall is cut away. 
Nevertheless, it can be seen that the pericardial cavity communi- 
