THE GASTRO-INTESTINAL CANAL. 147 



connective tissue, in which the blood and lymphatic 

 vessels ramify. The glands are tubular, sometimes 

 simple, sometimes divided, and often tortuous at 

 the base. They have a membrana propria, and, de- 

 pending upon differences in the epithelium which 

 line them, they are classified as: I. mucous glands ; 

 2. peptic glands. 



The general surface of the stomach is covered 

 with cylindrical epithelium. In the pyloric region, 

 and here and there in other parts, the glands, or 

 follicles, as they are often called, are lined through- 

 out with cylindrical epithelium ; these are the mu- 

 cous glands. 



The greater proportion of the glands, however, 

 are lined only at their orifices with cylindrical epi- 

 thelium ; deeper down in the gland we find usually 

 two kinds of cells : a, spheroidal or polyhedral cells, 

 with transparent or very finely granular bodies ; and 

 b y larger spheroidal, or somewhat flattened, very 

 granular cells, which usually lie outside the others, 

 between them and the membrana propria. These 

 are the so-called peptic cells, and these glands are 

 called peptic glands. The relative number of these 

 different kinds of peptic cells varies, depending upon 

 the degree of functional activity of the glands. 

 When they are secreting rapidly, the granular cells 

 are abundant ; when at rest they are few in number, 

 the smaller transparent cells preponderating. 



The arteries pass obliquely through the serosa 



