DISEASES OF THE STOMACH. 169 



The prognosis is even graver than in cases of invagination. Intes- 

 tinal hernia progresses very rapidly, necrosis soon sets in, and is 

 followed hy fatal consequences if the condition be not relieved. 



The treatment is exclusively surgical. As a general rule, whenever 

 colic is recognised as resulting from strangulated hernia, it is imme- 

 diately necessary to perform laparotomy in the right flank, and after 

 having discovered the cause of strangulation, to divide the mesentery, 

 epiploon, serous fold supporting the testicular cord, or accidental fibrous 

 bands, so as to free the herniated loop and avoid necrosis. If necrosis 

 already exist, the intestine may be resected, exactly as in invagination. 



DISEASES OF THE STOMACH. 



In ruminants diseases of the gastric compartments are numerous, 

 and, although they have been recognised since the earliest times, much 

 remains to be discovered concerning at least some of them. This fact 

 results from the imperfect state of our knowledge concerning the essential 

 phenomena of gastric digestion in ruminants. Digestion really consists 

 of a number of different acts — some mechanical or neuro-motor, some 

 chemical ; in addition to which must be reckoned the phenomena of 

 sensation, concerning which patients cannot give any information. 



The mechanical phenomena, consisting in the constant movement 

 of ingested material through the different compartments, rumination, 

 eructation, evacuation towards the intestine, etc., are well known to us; 

 and a careful examination of diseased animals enables us to estimate the 

 importance of changes in them. 



On the other hand, the chemical phenomena are little understood. 

 It has hitherto been considered that the rumen, reticulum, and omasum 

 are only simple diverticula, with mechanical functions, and that the 

 abomasum is the reservoir in which the chemical changes take place. 

 Another view, which is perhaps not altogether justified, presupposes 

 that the chemical transformation of the food in the abomasum takes 

 place as in other animals, and in particular as in man, in whom the 

 chemistry of gastric digestion has been the object of extremely careful 

 research by certain French and other pathologists. We do not believe 

 (for reasons too long to be explained here) that the gastric digestion of 

 ruminants, or even of herbivora in general, can be identified with that 

 of omnivora. 



The nature of the food being totally different, the chemical reactions 

 in the stomach and intestines are also different ; in proof of which we 

 need only cite the single fact that ptyalin is absent from the saliva. 

 Straw and oats are not digested in the same way as a mutton cutlet. 



But even supposing that the broad outlines of physiological action 



