496 LECTURE XXI. 



cells are designated in the cardiac glands as chief, central, principal, or 

 adelomorphous cells, while the latter are called either border, parietal, 

 or delomorphous cells. Between the gland-cells there are fine secretion 

 capillaries which surround the border cells like a basket. For a long 

 time it was believed that this histological distinction of two kinds of cells 

 also corresponded to a physiological distinction. The fundus glands were 

 supposed to secrete only pepsin, while the pyloric glands merely formed 

 mucous. That this is not the case is shown by the fact that the secretion 

 carefully collected from the latter portion of the stomach does actually 

 contain pepsin. The pyloric and cardiac parts can easily be isolated,, and 

 in this way " small stomachs" are formed in the Pawlow sense, and by 

 means of fistulas the contents of each may be studied by itself. At 

 present we are still undecided as to the especial significance of the chief 

 cells and of the border cells. It has been established that the former 

 take part in the formation of pepsin and rennin, but the function of the 

 border cells remains vague. From the fact that the pyloric part of the 

 stomach produces little or no hydrochloric acid, it has been suggested that 

 the border cells produce the acid, but there has never been any direct 

 proof of this. 



Whatever the functions of the cells may be, it is to be said that much 

 the same changes take place in them during activity as in the cells of 

 the salivary glands. During a period of rest the secretion is formed 

 which is given up during the period of work. 



All the secretions of the mucous membrane of the stomach and its 

 glands taken together form the so-called gastric juice. It consists in part 

 of mucous which is given off chiefly from the superficial surface of the 

 mucous coat, together with the ferments, hydrochloric acid, inorganic 

 salts, and small amounts of other organic substances. Exact studies 

 concerning the formation of the gastric juice and of its dependence upon 

 outward influences were first made possible by the operative skill of 

 Pawlow and his pupils. His methods and his investigations gave us the 

 first insight into the relation between the secretions of the stomach 

 and physiological conditions. Pure gastric juice may be obtained by the 

 establishment of a fistula, best in combination with one in the oesophagus. 

 Thus the food swallowed by the animal may be removed before it reaches 

 the stomach. In this way a fictitious feeding is obtained, and the gastric 

 juice is not contaminated with the food, nor with the intestinal products. 

 It was found advisable also to isolate a portion of the stomach, forming 

 a little stomach, or blind sack, in which the secretion process could be 

 studied by means of a fistula while digestion was going on in the rest of 

 the organ. The gastric juice flowing out of such a fistula is, after filtering 

 off the mucous, clear as water, odorless, and of an acid taste. This taste 

 is due, as has been stated, to the presence of free hydrochloric acid. In 



