THE DIGESTIVE APPARATUS. 



143 



higher isolated prominences (Fig. 134, a), are met with 

 there, or projecting folds, which are united in crossing each 

 other. 



The glands open only in the valleys, and never on a hill 

 or a fold. Numerous differences of the gastric surfaces 

 occur according to the variety of animal. In general, the 

 cardial half of the stomach presents a thinner and more 

 even mucous membrane than the pyloric portion. The 

 mucous membrane may here, at last, acquire an elevation 

 of 2 mm. 



An enormous quantity of tubular 

 glands (Fig. 134, b) permeate the 

 mucous membrane. The massiveness 

 of the latter is, therefore, in compar- 

 ison to this embedment, but slight. 

 We find an ordinary soft connective 

 tissue (Fig. 135, a). Lymphoid meta- 

 morphosis of the latter may, however, 

 take place. 



The glandular tubes of the stomach 

 have been divided into two differ- 

 ent forms ; the so-called peptic- 

 gastric glands and the gastric- mucous 

 gland. 



The former constitute the more dis- 

 seminated and more important 

 glandular formations (Fig. 134). 

 They open in part singly (Fig. 

 128), in part by the conjunction 

 of several tubes into a common 

 excretory duct (Fig. 136, 1). 



In both cases the aperture 

 appears in the transverse sec- 

 tion to be rounded (a), and 

 lined with the ordinary slender, 

 high cylindrical epithelium of the gastric mucous membrane 

 (Fig. 128, a, 136, a). 



Fro. 1 34. — Vertical section of 

 the human gastric mucous mem- 

 brane ; a, surface papillae ; b, 

 glands. 



Fig. 13s. — Transverse section through the 

 gastric mucous membrane of the rabbit; a, 

 tissue of the mucous membrane : b, trans- 

 verse sections of empty and injected blood- 

 vessels, c ; <i, spaces for the glands. 



