514 DIGESTION. 



tained 73 per cent of the coagulable protein from a fistula in the ileum 

 (2-3 cm. in front of the caecum). Elastin is, according to LONDON, 1 

 more slowly digested in the small intestine than other proteins. KUT- 

 SCHEB and SEEMANN, ABDERHALDEN, LONDON and collaborators 2 have 

 also found that non-biuret giving products and amino-acids are regularly 

 split off, probably by the combined action of trypsin and erepsin. These 

 amino-acids occur to a slight extent only, but from this no conclusion 

 can be drawn as to the extent of amino-acid formation, because we do 

 not know the extent of their absorption. The digestion of protein 

 in the intestine, it seems, according to ABDERHALDEN, LONDON, OPPLER 

 and REEMLiN, 3 is similar to the artificial digestion with trypsin, namely, 

 that the destruction takes place step-wise, that certain amino-acids, 

 such as tyrosine, are split off earlier than others. ZUNZ 4 found the same 

 end result in the protein cleavage in the small intestine, with bread as 

 with meat feeding. LONDON, SCHITTENHELM and WIENER 5 found 

 that a cleavage of nucleic acids with the formation of nucleosides 

 occurred in the lower part of the jejunum and ileum. 



The decomposition products of the proteins formed by the action of 

 gastric juice can, according to LONDON. 6 be absorbed without further 

 cleavage by the pancreatic juice, and a further cleavage in the intestine 

 seems to be more necessary for assimilation than for absorption. 



The carbohydrates and the fats (LEVITES 7 ) may be so completely 

 split in the stomach and small intestine that their absorption is com- 

 plete before the contents pass into the caBcum. According to LONDON 

 and POLOWZOWA 8 a strong cleavage of starch, dextrins and disaccharides 

 takes place, especially in the duodenum, while the absorption is less 

 strong here. The carbohydrates are here prepared for the absorption 

 taking place in the lower parts of the intestine, though the cleavage also 

 goes on in the other parts, namely in the jejunum and the upper part 

 of the ileum. 



As above remarked, ordinarily no putrefaction takes place in the 

 small intestine, but occurs generally only in the large intestine. This 



1 London and Suleima, Zeitschr. f. physiol. Chem., 46; London, ibid., 60. 

 2 Kutscher and Seemann. ibid., 34; Abderhalden and London, with Kautzsch, 

 ibid., with L. Baumann, ibid., 51, with v. Korosy, ibid., 53. 



3 Zeitschr. f. physiol. Chem., 55 and 58. 



4 Intern. Beitr. z. Pathol. u. Ther. d. Ernahrungsstorungen, 2, 195, 459 (1910 and 

 1911). 



5 Zeitschr. f. physiol. Chem., 72, 459 (1911). 



6 Ibid., 49. 



7 Ibid., 49 and 53. 



., 56. 



