THE STOMACH AND INTESTINE. 269 



phous cells. The parietal cells lie against the walls of the gland that 

 is, they rest on its basement membrane and are particularly numer- 

 ous in the neck and body of the gland, but not so numerous in its fun- ' 

 dus. Their bodies often extend more or less beyond the even line 

 of the remaining cells, thus forming, together with the membrana 

 propria, a protuberance (particularly noticeable in the pig, where 

 almost the entire cell may be enveloped by the basement membrane, 

 giving it an appearance of being entirely extraglandular). Toward 

 the lumen of the gland the contour of these cells is modified by 

 pressure on the part of the adjacent cells belonging to the other 

 variety, and they are indented according to the number of the latter. 

 Occasionally, a process is seen extending from a parietal cell to the 

 lumen of the gland. The parietal cells are larger than the cells of 

 the other variety and richer in protoplasm ; they are of an irregular 

 oval or triangular shape and possess, as a rule, a single nucleus, 

 although in man numerous parietal cells with two nuclei are found. 

 The parietal cells are clearer in fresh preparations than are the chief 

 cells, while in fixed preparations the reverse is generally the case. 

 They stain deeply in Heidenhain's iron-lac-hematoxylin, are dark- 

 ened by osmic acid, and show an affinity for acid stains, especially 

 for eosin, also for congo-red and for neutral carmine solutions. 



According to Erik Muller and Golgi (93), there exists in the 

 peripheral protoplasm of each parietal cell a system of canals in 

 the form of a network communicating with the lumen of the gland 

 and varying in structure according to the physiologic condition of 

 the cell wide-meshed in a state of hunger and fine-meshed during 

 digestion. A peripheral zone differing from the rest of the cell- 

 body may occasionally be demonstrated in the parietal cells (mouse) 

 by using the method of von Altmann. 



The chief cells are short, irregular, columnar structures whose 

 narrower portions point toward the lumen of the gland. They are 

 situated either directly between the lumen and the basement mem- 

 brane of the gland, or their basilar surfaces border on a delomor- 

 phous cell. They are found throughout the tubule of the gland 

 and occupy the spaces between the delomorphous cells. The chief 

 cells of the fund us glands are of two varieties, as has been shown 

 by Bensley. The chief cells of the body of the gland are charac- 

 terized by the possession of relatively large zymogen granules,! 

 which are found in the inner portion of the cells. These granules 

 are used up during secretion. The outer or basal portion of the 

 cells contains a pro zymogen, not in granular form but recognized by 

 its staining reaction. The chief cells of the neck are slightly 

 smaller than those of the body, and differ from these in that they 

 do not possess zymogen granules and prozymogen only in small 

 amounts, but show by their reaction to certain stains that they are 

 mucus-secreting cells. 



The structure of the pyloric region of the stomach differs in 

 some respects from that of the cardiac end and fundus. There 



