122 THE STOCK owner's ADVISER. 



right, or pyloric, portion. It lias an opening on the left, lead- 

 ing into the oesophagus, through which the food enters, and 

 another on the right, which communicates with the first portion 

 of the intestine called the duodenum. The walls of the stomach 

 are composed of three coats — an external, middle, and an in- 

 ternal coat. The external coat is simplv a serous membrane and 

 a reflection of the peritoneum. The middle or muscular coat 

 consists of three sets of fibers — an external longitudinal, a mid- 

 dle circular, and an internal oblique layer. The action of the 

 different fibers produces a churning motion, which brings each 

 portion of the food in contact with the mucous surface. The 

 internal or mucous coat is different on the right and left portions 

 of the stomach. In the cardiac portion it is called the cuticular. 

 It is continuous with the mucous membrane of the CEsophagus, 

 which it resembles in structure and appearance. It is covered 

 by a thick layer of stratified epithelium. It covers about one- 

 third of the internal surface of the stomach. The villous or true 

 digestive coat is reddish in color, soft, very vascular, and vel- 

 vety-looking. The line of demarcation between the two por- 

 tions is abrupt and dentated. The colors of the coverings are 

 very dissimilar; the one has a reddish color, while the other is 

 white. The villous portion has shallow depressions, or alveolar, 

 into which the gastric follicles open; at the pyloric end some of 

 these follicles terminate in dilated sacs, or divide into two or 

 more tubes. Some of them secrete gastric juice; others mucous. 

 The use of the stomach is to macerate the food by the action of 

 its muscular walls, and also to saturate it with mucous and gas- 

 tric juice, the latter containing a principle called pepsine, which 

 acts chemically on albuminous matter. The food during diges- 

 tion in the stomach is kept in motion by the peristaltic action of 

 its walls. By the contractions of its muscular fibers, currents 

 are set up in its contents, the food travelling along the large 

 curvature and returning by the lesser, while, as digestion pro- 

 ceeds, certain portions are passed through the pylorus into the 

 duodenum. 



