526 SPECIAL PHYSIOLOGY. 



ridges. The unstriped muscular fibres found in the submucous coat 

 are placed immediately beneath these glands, and probably assist in 

 expelling their secretion. 



Besides these proper gastric or peptic glands, there are found, es- 

 pecially near the pylorus, clusters of larger simple and compound 

 mucous glands, which are lined throughout with cylindrical epithe- 

 lium, and are supposed to secrete gastric mucus. 



In certain conditions of the stomach, especially during and after 

 digestion, and also in irritation and inflammation of this organ, and 

 nearly always in the stomachs of infants, numerous small, milky-white, 

 elevated spots are seen scattered over the mucous membrane. These 

 consist of lenticular closed sacs, not opening on the surface ; they are 

 filled with a white, semifluid and finely granular substance. They 

 resemble the closed sacs of the tonsils, and of the so-called solitary 

 and agminated glands of the small intestine, to be hereafter noted; 

 like them, they are now considered to be appendages of the absorbent 

 system. The lymphatics of the stomach form a fine network near 

 the surface of the mucous membrane, and coarser plexuses in the sub- 

 mucous coat, all intimately connected together. 



The gastric juice, during the digestive process, or under the excite- 

 ment of condiments, small stones, and other irritant bodies, exudes 

 from every part of the mucous membrane of the stomach, which then 

 assumes a bright red hue. The secretion pouring from the tubules, 

 oozes from the alveoli in minute drops, which speedily run together, 

 and cover the whole mucous membrane. This has been seen by Dr. 

 Beaumont and others, in the case of Alexis St. Martin, a Canadian 

 voyageur, the interior of whose stomach was exposed by a gunshot 

 injury. 



The condition of the stomach, and the formation of the gastric juice, 

 as of other secretions, are influenced by the nervous system. It was 

 shown, by Dr. John Reid, that the division of both pneumogastric 

 nerves, in the neck of a dog, in the first instance, arrested digestion ; 

 but that, if the animal lived sufficiently long, the process might be 

 restored ; for then, generally, the state of emaciation, which followed 

 the experiment, was removed, acid and partly digested food was 

 vomited, and absorption and chylification took place. This restora- 

 tion of function was not due to reunion of the divided nerves, for por- 

 tions of the nerves were removed, or care was taken to keep the cut 

 ends apart. Bernard also found, that, on division of these nerves, the 

 stomach became pale, its walls relaxed, and the formation of gastric 

 juice was instantly arrested, digestion being thus stopped. On the 

 other hand, galvanizing these nerves increased the gastric secretion. 

 According to Longet, however, the pneumogastric nerves are rather 

 the motor nerves of the stomach, their division, as he believes, chiefly 

 affecting the movements of that organ ; for he found that milk, intro- 

 duced into the stomach one or two days after the operation, always 

 became coagulated ; whilst, although large portions of food were only 

 acted upon on the surface, owing to the paralysis of the muscular 

 fibres, and the necessary absence of the churning movements of the 

 stomach, yet small portions were actually digested. By Budge, it is 



