THE CAT 213 



called the suspensory ligament; it is the median, vertical mem- 

 brane, which appears between the right and left halves of the 

 liver and joins it with the diaphragm. Appearing on the right 

 side of the liver is the green gall bladder. The great omentum, 

 which covers the viscera back of the liver, is the mesentery of the 

 stomach. It arises from the peritoneum in the mid-dorsal line 

 between the diaphragm and the kidneys, and, instead of passing 

 directly to the stomach, goes first posteriorly to the region of the 

 pelvis, and then, turning on itself, passes forward to the greater 

 curvature of the stomach. Thus it will be seen to form a great 

 sac, the omental sac, which lies ventral to almost the entire ab- 

 dominal viscera. 



The abdominal cavity in mammals is not the equivalent of the 

 entire abdominal cavity of other vertebrates but only of the 

 middle and hinder portions of it. In other vertebrates no dia- 

 phragm and consequently no thoracic cavity is present, the body 

 cavity being divided into the abdominal and pericardial cavities. 

 In mammals the pericardial cavity with the heart is contained in 

 the thoracic cavity. 



Exercise 6. Draw a semidiagrammatic sketch of the abdominal cav- 

 ity, in an outline of the body, together with the organs which ap- 

 pear in a ventral view. Carefully label all of them. 



The Digestive System. This is made up of the mouth, pharynx, 

 oesophagus, stomach, small intestine, large intestine, salivary 

 glands, liver, and pancreas. Lift up the great omentum and cut 

 it away, being careful not to injure the viscera with which it is 

 joined. The flat, dark-red spleen will be seen in the omentum on 

 the left side of the body, close to the stomach ; also the large splenic 

 veins and arteries. Close to the dorsal surface of the stomach and 

 in contact with the spleen is a portion of the long, flat, light-red 

 pancreas. Do not cut or remove any of these organs. 



The stomach and intestine are thus fully exposed. Observe 

 carefully the form and position of the stomach. Note where the 

 oesophagus comes through the diaphragm and joins it. The 

 stomach has two distinct divisions: the broad anterior portion, 

 which lies directly back of the diaphragm on the left side of the 



