476 



MANUAL OF HISTOLOGY. 



elements then make their appearance, and after them the specific gland or 

 peptic cells (fig. 457). The form of these when isolated is more or 

 less cubical (fig. 459). They are of considerable size, and almost completely 

 fill the gland tubule. 



In man they had only been met with in a more or less decomposed 



Fig. 457. Three stomach 

 glands from the human 

 being, partly filled with 

 peptic cells. 



Fig. 458. Peptic glands from the 

 human stomach after treat- 

 ment with alkalies. 



condition (&). In suitable objects (a, c-g) they appear roundish or inde- 

 finitely angular, 0'0323-0'0.187 mm. in diameter. They present a delicate 

 boundary layer (e, /, g), or are quite membraneless (a, c), and are com- 

 posed of protoplasm which becomes clear in 

 acetic acid, surrounding a nucleus 0074 mm. 

 in diameter, within which a nucleolus may 

 be recognised. 



Of late years, however, this older view of 

 their nature has been shown to be quite incom- 

 plete. Recent investigations by Heidenliain 

 and Rollett have adduced much that is new, 

 but the extreme difficulty of the subject has 

 prevented definite conclusions being drawn on 

 all points. 



The conclusions drawn from our own personal 

 observations are as follows : The peptic gland consists of several parts : 

 with Rollett we distinguish four. 



Fig. 459. Different forms of 

 peptic cells from man. 



