THE GASTRIC MUCOSA 199 



character. These have already been described in other animals 

 (Stohr (29), Trinkler (23), Nussbaum (20)). Nussbaum, how- 

 ever, does not consider these smaller cells to be the same as 

 oxyntic cells. 



General Consideration's. 



These observations show firstly that the term ' chief ' or 

 ' central ' cells is inadequate, since there are two types differing 

 widely from each other. Secondly that the cells of the cardiac 

 and pyloric regions are similar in structure and of the same 

 characteristics as the mucoid cells of the fundus. Thirdly that 

 the fundus is the all-important region of the stomach from 

 the point of view of the secretion of gastric juice, the other 

 two regions being small by comparison and containing no 

 recognizable zymogen-secreting cells. 



Let us first consider the characters of the two types of central 

 cells. We have seen that the peptic cell is granular (or reticu- 

 lated) and that after a period of activity the granules diminish 

 in number and are replaced at the base of the cell by ergasto- 

 plasmic fibres. In the case of the mucoid cell the cytoplasm 

 is also granular (when fresh), bui functional changes do not 

 cause any alteration in its architecture. The nucleus of the 

 peptic cell at rest is irregularly rounded or ovoid, and is applied 

 against the basement membrane, but during digestion is more 

 regular in outline and frees itself from the base so far as to 

 occupy a more central position. The mucoid cell-nucleus, on 

 the other hand, is not markedly changed either in shape or 

 position. There are also the differences in staining reactions. 

 The peptic cell is coloured in an entirely different manner 

 from that of the mucoid cell (compare m and p, PI. 8, fig. 3). 

 This difference is manifested not with one staining method 

 alone but with several, although Mallory's is the best for the 

 purpose. Both types of central cell may be seen in man, dog, 

 and rabbit (and also in the frog) ; they are probably common to 

 all mammals. 



There can thus be no doubt regarding the separate existence 

 of these two types of cells. Edinger's theory that all the 



