DIGESTION IN THE STOMACH 459 



stomach, at least the fundus, acts in the first place as a storage chamber, 

 follows from the shape of this organ, especially in certain animals, and 

 this function becomes especially prominent in certain new-born animals, 

 as dogs and cats. In these animals the gastric secretion contains acid 

 but no pepsin, and the casein of the milk is precipitated by the acid 

 alone as solid lumps or as a solid coagulum filling the stomach. Gradually 

 small quantities of this coagulum pass into the intestine and an overbur- 

 dening of the intestine is thus prevented. In other animals, as the 

 snake and certain fishes which swallow entire animals, the major part 

 of the digestive work goes on in the stomach. The importance of the 

 stomach for digestion cannot therefore be established in all instances. 

 It varies in different animals and differs even in individual animals of 

 the same species, depending upon the fineness or coarseness of the food, 

 upon the greater or less rapidity with which peptonization takes place, 

 and also upon the rapid or slow increment in the quantity of hydrochloric 

 acid, etc. 



In regard to the extent of chemical digestive work, i.e., in the first 

 place the destruction of protein in the stomach, we have numerous 

 researches, some carried out by the use of older methods and others by 

 using newer and more reliable methods. Among these latter we must 

 mention those of ZUNZ, LONDON and collaborators, TOBLER, LANG and 

 CoHNHEiM. 1 These investigations refer to the conditions in dogs, and 

 as shown by ROSENFELD 2 in horses, and by LOTSCH 3 in pigs, that the 

 conditions are different in other animals. The following description 

 applies only to dogs. 



In the dog ABDERHALDEN, LONDON and co-workers 4 have shown 

 that in the stomach proteoses and peptones, besides so-called rest bodies, 

 are formed, but no amino-acids, or at least in any mentionable quan- 

 tity. In like manner we must agree in the belief that a part of the 

 protein always leaves the stomach undigested and that the chief mass, 

 about 80 per cent, passes into the intestine more or less digested. 

 LONDON and SANDBERG 5 indeed have from their experiments with 

 gliadin or with egg albumin (LONDON), suggested the proposition that 

 a certain percentage of the partaken protein is always digested, irre- 



1 Tobler, Zeitschr. f. physiol. Chem., 45; Lang, Bioch. Zeitschr., 2; Cohnheim, 

 Munch, med. Wochenschr., 1907. In regard to the works of Zunz, London, and 

 collaborators, see footnotes 3 and 4, p. 457. 



2 Rosenfeld, Ueber die Eiweissverdauung im Magen des Pferdes, Inaug.-Dissert., 

 Dresden, 1908. 



3 Lotsch, Zur Kenntnis der Verdauung von Fleisch im Magen und Diinndarm des 

 Schweines, Inaug.-Dissert. Freiburg i. Sa., 1908. 



4 Abderhalden and London, with Kautsch, Zeitschr. f. physiol. Chem., 48, with 

 L. Baumann, ibid., 51, and with v. Korosy, ibid., 51. 



5 Zeitschr. f. physiol. Chem., 56 



