THE DIGESTIVE AND RESPIRATORY SYSTEM 295 



ventral mesenteries. In spite of the great increase of size 

 these typical relations remain in the case of the liver, and its 

 two suspensory mesenteries become the ligamcntum hepato- 

 gastriciim [y~\ (sometimes termed the lesser omcntnm), and 

 the ligamentum suspensoriitm hepatis \_x}. While primarily 

 the entire length of the alimentary canal that passes through 

 the ccelomic region becomes attached by both a dorsal and a 



A 



FIG. 82. Diagrams showing the relation of the liver and pancreas to 

 the peritoneum. [After HERTWIG.] 



(a) Lateral view with ventral surface towards the left. The organs are seen 

 lying within the peritoneum, which is represented in a vertical plane stretched across 

 from mid-dorsal to mid-ventral lines, (b) A cross-section. The place through which 

 it is taken is indicated approximately in (a) by the arrows. 



Organs: s, stomach; n, spleen; /, liver; p, pancreas; i, intestine. Ligaments: x, 

 ligamentum suspensorium hepatis; y, ligamentum hepatogastrium ( = lesser omentum) ; 

 a and b, parts of the mesogastrium which form the pancreatic ligaments similar to 

 those of the liver. 



ventral mesentery, the ventral one becomes lost below the 

 region of the liver, thus leaving a sharp ventral edge to the 

 two hepatic ligaments. 



The gall-bladder is formed as an enlargement of the hepatic 

 duct and is by no means of universal occurrence; it develops 

 rather in response to certain conditions, much as in the case 

 of the crop, and its slight physiological importance is shown 

 by its occurrence in one of two allied animals and its ab- 



