THE STOMACH. 



463 



comes into contact with the gastric fluid, by tlie 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 great differences in the various domesticated 

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



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



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

 the grc;it resembhiuce between the two organs. Like the latter, the stomach of the Rabbit is 

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

 smaller eurvatnie ; so that the organ shows a large tuberosity in cul-de-mc on the left of tlie 

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

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



2. The Stom.^ch of the Pig (Fig. 289). 



The Pig's stomach is simple, like that of tlie 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 oesopliagus opens into the stomach p- 267 

 by a wide iiifundibulum, and the mucous mem- 

 brane of that tube is prolonged over the ga.-tric 

 surface in a ladius of from two to three inches 

 around the cardia. Here again we find a '• tiace 

 of tlie 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 

 tliicker in the right than the left extremity; 

 near the cesophagus, 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 

 tlie left extieniity of the organ than in other 

 animals. The oesophageal mucous membrane 

 is not continued beyond the margin of that 

 orifice. The simple stomach of Carnivora forms 

 only a single sac, whose internal mucous iiieni- 

 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 the 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 IJ pints, and the maximum If gallons; he calculates the 

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

 stomachs. 



stomach of thk dog. 

 A, (Esophagus ; B, pylorus. 



