392 MANUAL OF HISTOLOGY. 



cous membrane with osmic acid, after Nussbaum's method. 

 By him the chief cells are said to develop into parietal cells, 

 through an increas3 of their volume and a filling up with the 

 gastric ferment. The considerations which led him to form 

 this opinion are as follows : 1, the occurrence of bodies which 

 represent transition-forms between chief cells and parietal 

 cells ; 2, the analogy of this assumed metamorphosis of gas- 

 tric corpuscles (i.e., the conversion of chief cells into parietal 

 cells), with similar changes, known to occur in other glands 

 during active secretion ; 3, the fact that many animals which 

 secrete pepsin have only the parietal cells ; 4, the results of an 

 examination of the mucous membrane of starving animals, 

 which revealed only the chief -cell form of gastric corpuscles ; 

 and 5, the apparent discrepancy in the descriptions of these 

 bodies by competent histologists some observers regarding 

 the chief cells, others the parietal cells, as exclusively pepsin- 

 ogenous. 



Still more recently, Stohr has (Verhandl. d. p7iys.-med. 

 Gesel. in Wurzburg, 1881, p. 101) studied the histology of the 

 gastric epithelium. His specimens were derived from the fresh 

 stomach of a criminal immediately after execution of the latter. 

 The man had taken no nourishment for some hours before his 

 death. The principal conclusions of Stohr are : 1, the epithe- 

 lia of the mucous glandules are not destroyed during the pro- 

 cess of secretion, but, like those of the true gastric glands, con- 

 tinue their existence ; 2, the parietal groups of cells represent 

 those portions of the mucous corpuscles which have not un- 

 dergone mucoid metamorphosis, being made up of unaltered 

 protoplasm. 



From the above contradictory statements it appears that 

 even to-day our intimate knowledge of the gastric mucous 

 membrane, and especially its epithelia, is far from being in a 

 satisfactory condition. It will have to be reserved for future 

 investigations to dispel the uncertainty still existing with re- 

 gard to some of the most interesting details of the physiologico- 

 histological characteristics of the inner coat of the stomach. 



The blood-vessels of the stomach have an arrangement simi- 

 lar to that of the oesophagus. In the mucous membrane, how- 

 ever, we find abundant plexuses of capillary vessels surround- 

 ing the gastric glands. These networks intercommunicate, and 

 just beneath the surface-epithelium they become especially 



