484 DIGESTION. 



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 are formed, but no amino- 

 acids, or at least not in any mentionable quantity. The scanty occurrence 

 of amino-acids is substantiated by the observations of ZUNZ and others 5 

 that the amount of amino-nitrogen titratable with formol in the stomach 

 contents, is only small. 



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

 always leaves the stomach undigested and that the principal mass, about 

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

 it also seems as if the peptones occur in the pylorus part to a greater 

 extent than the proteoses, while in the fundus part the reverse is .the 

 case. Of the dissolved protein of the entire stomach-contents about 

 60 per cent exists as proteoses. Opinions are also contradictory in 

 regard to the absorption of the decomposition products of the proteins 

 in the stomach. While several investigators, like TOBLER, LANG, COHN- 

 HEIM, ZUNZ and others accept such an absorption, LONDON and co-workers 

 positively deny this. 



The digestion of sundry foods is not dependent on one organ alone, 

 but is divided among several. For this reason it is to be expected that 

 the various digestive organs can act for one another to a certain extent, 

 and that therefore the work of the stomach could be taken up more or 

 less by the intestine. This in fact is the case. Thus the stomachs of 

 dogs and cats have been completely extirpated or nearly so (CZERNY, 

 CARVALLO and PACHON, LONDON and collaborators), or that part 

 necessary in the digestive process has also been eliminated by plugging 

 the pyloric opening (LUDWIG and OGATA), and in both cases it was pos- 

 sible to keep the animal alive, well fed, and strong for a shorter or 

 longer time. The extirpation of the stomach has also been repeatedly 



Nobler, 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 1, 2 and 3, p. 482. 



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

 Dresden, 1908. 



8 Lotsch. Zur Kenntnis der Verdauung von Fleisch im Magen und Diinndarm des 

 Schweines, Inaug.-Dissert. Freiburg i. Sa., 1908; see also Abderhalden, Klingemann 

 and Pappenhusen, Zeitschr. f. physiol. Chem. 71, 411 (1911). 



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

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



6 Intern. Beitr. zu Path. u. Ther. d. Ern.-Stor. 2; London and Rabinowitsch, 

 Zeitschr. f. physiol. Chem. 74. 



