The Digestive System 153 



walls. When empty the lining of this part of 

 the stomach is thrown into a few comparatively 

 large folds, but when greatly distended with food, 

 as it sometimes is, the internal folds are com- 

 pletely obliterated and the muscular layers are 

 stretched until they have scarcely an eighth of 

 their original thickness. In Figure 34 the stomach 

 is considerably distended. 



The large region of the stomach frequently 

 contains a number of stones, and for that reason, 

 probably, is sometimes spoken of as the gizzard. 

 In one thirty-inch alligator fourteen pebbles of 

 irregular shape, varying in largest diameter from 

 four to seventeen mm. and aggregating six grams 

 in weight, were found. Voeltzkow (78) says that 

 gastroliths of two to three cm. diameter are 

 found in the stomach of the adult Madagascar 

 crocodile. 



Neither the transverse fold nor the smooth, 

 lateral disks (or shields) described by Chaffanjon 

 could be seen in either the empty or in the dis- 

 tended stomach. 



The smaller part of the stomach, Fig. 34, p, lies 

 to the right and somewhat ventrad to the anterior 

 region of the larger part, near the entrance to the 

 oesophagus. It connects by a fairly large opening 

 with the larger part of the stomach, and by a 

 smaller opening with the duodenum. The former 

 opening apparently has no valve, unless it be a 

 slight sphincter muscle ; the latter is guarded by 



