THE STOMACH. 



463 



comes into contact with the gastric fluid, by the action of which its principal 

 elements, and particularly the albuminoid substances, become soluble and 

 absorbable. 



Differential Characters in the Stomach of the other Animals. 



The stomach is an organ that exhibits groat differences in the various domesticated 

 animals. In tlie study of these differences, we will proceed from the simple to the complex. 



1. The Stomach of the Kabbit (Fig. 286). 

 The stomach of the Rabbit is described immediately after that of Solipeds, because of 

 the great resemblance between the two organs. Like the latter, the stomach of the Kabbit is 

 divided into two sacs— a right and left— and the oesophagus enters it at the middle of its 

 smaller curvature ; so that the organ shows a large tuberosity in cul-de-sac on the left of the 

 cardia. The sac is perhaps more elongated, narrower, and more curved than in that of the 

 Horse. The total capacity of the organ is from f of a pint to 1 pint. 



2. The Stomach of the Pig (Fig. 289). 



The Pig's stomach is simple, like that of the Horse, but it is less curved on itself, and 

 the cardia is nearer the left extremity ; the latter has also a small conical dilatation, which 

 has been compared to a cowl curved back- 

 wards. The cesophagua opens into the stomach pj^ 267 

 by a wide infundibulum, and the mucous mem- 

 brane of that tube is prolonged over the ga>tric 

 surface in a laiiius of from two to three inches 

 around the cardia. Here again we find a " tiace 

 of the division into two sacs," common to 

 Solipeds, and to nearly all Rodents. 



The capacity of the Pig's stomach averages 

 from 1| to 2 gallons. (The muscular tunic is 

 thicker in the right than the left extremity ; 

 near the oesophagus, the serous tunic shows 

 some transverse folds.) 



3. The Stomach of Carnivora (Fig. 267). 

 In the Dog and Cat the ventriculus is 

 but little curved, and is pear-shaped, the small 

 extremity corresponding to the pylorus. The 

 cardia is dilated like a funnel, and is nearer 

 the left extiemity of the organ than in other 

 animals. The oesophageal mucous membrane 

 is not continued beyond the margin of fliat 

 orifice. The simple stomach of Carnivora forms 

 only a single sac, whose internal mucous mem- 

 brane presents, throughout its whole extent, 

 the same organization as the membrane lining 

 the right sac of Solipeds. This membrane is 

 remarkable for the regular and undulated folds 

 it forms when the stomach is empty. Nothing 

 is more variable than tlie capacity of the Dog's 



stomach, because of the great differences in the size of this animal, according to breed. Colin 

 has found the minimum to be 1^ pints, and the maximum If gallons; he calculates the 

 average to be about 2J quarts. In the Cat, the average is from 2 to 2i gills. 



4- The Stomach of Ruminants (Fig. 268). 

 These animals are distinguished from the others by the faculty they possess of swallowing 

 their food after imperfect comminution, and causing it to return again into the mouth to 

 submit it to -a second mastication, previous to final deglutition. The gastric apparatus is 

 admirably arranged to effect this physiological finality, and is remarkable for its enormous 

 development, as well as its division into four separate pouches, which are regarded as so many 

 stomiichs. 



stomach of the dog. 

 A, (Esophagus ; B, pylorus. 



