FOOD AND DIGESTION. 357 



ininates in a blind extremity or fundus near the inuscularia mucosse, is 

 lined by cells continuous with the cubical or central cells of the neck, 

 but longer, more columnar and more transparent. In this part are a 

 few parietal cells of the same kind as in the neck (fig. 249). 



As the pylorus is approached the gland ducts become longer and 

 the tube proper becomes shorter, and occasionally branched at the 

 fundus. 



(b) Pyloric Glands. These glands (fig. 251) have much longer ducts 

 than the peptic glands. Into each duct two or three tubes open by 

 very short and narrow necks, and the body of each tube is branched, 

 wavy, and convoluted. The lumen is very large. The ducts are lined 

 with columnar epithelium, and the neck and body with shorter and 

 more granular cubical cells, which correspond with the central cells of 

 the cardiac glands. During secretion the cells become, as in the case of 

 the cardiac glands, larger and the granules restricted to the inner zone 

 of the cell. As they approach the duodenum the pyloric glands become 

 larger, more convoluted and more deeply situated. They are directly 

 continuous with Brunner's glands in the duodenum. (Watney.) 



Changes in the gland cells during secretion. The chief or cubical 

 cells of the cardiac glands, and the corresponding cells of the pyloric 

 glands during the early stage of digestion, if hardened in alcohol, appeal- 

 swollen and granular, and stain readily. At a later stage the cells be- 

 come smaller and less granular, and stain even more readily. The 

 parietal cells swell up, but are otherwise not altered during digestion. 

 The granules, however, in the alcohol-hardened specimen, are believed 

 not to exist in the living cells, but to have been precipitated by the 

 hardening reagent; for if examined during life they appear to be con- 

 fined to the inner zone of the cells, and the outer zone is free from 

 granules, whereas during rest the cell is granular throughout. These 

 granules are thought to be pepsin, or the substance from which pepsin 

 is formed, pepsinogen, which is during rest stored chiefly in the inner 

 zone of the cells and discharged into the lumen of the tube during 

 secretion. (Langley.) 



Lymphatics. Lymphatic vessels surround the gland tubes to a 

 greater or less extent. Toward the fundus of the peptic glands are 

 found masses of lymphoid tissue which may appear as distinct follicles, 

 somewhat like the solitary glands of the small intestine. 



Blood-vessels. -The blood-vessels of the stomach, which first break 

 up in the sub-mucous tissue, send branches upward between the closely 

 packed glandular tubes, anastomosing around them by means of a fine 

 capillary network, with oblong meshes. Continuous with this deeper 

 plexus, or prolonged upward from it, so to speak, is a more superficial 

 network of larger capillaries, which branch densely around the orifices 

 of the tubes, and form the framework on which are moulded the small 



