ALIMENTARY TRACT AS AN EXCRETORY SYSTEM. 315 



former has, however, found in his own experiments and has 

 collected facts from the literature which show that substances 

 which are ordinarily believed to be excreted chiefly or ex- 

 clusively through the kidneys are eliminated also by the 

 intestine. CLAUDE BERNARD found as far back as 1859 that 

 urea occurs in the saliva and the gastric juice, and that in 

 nephritis and after removal of the kidneys this substance is 

 excreted to a large extent by the intestine. From this fact 

 CLAUDE BERNARD concludes that the intestine may supple- 

 ment the kidneys in eliminating the various constituents of 

 the urine. The presence of urea in the intestinal juice of 

 sheep has been demonstrated by PREGL, and MACCALLUM 

 found this substance normally present in the same secretion 

 of the rabbit. 



Of great interest is the fact discovered by MACCALLUM that 

 in a certain form of experimental diabetes the sugar is elimi- 

 nated, not only by the kidneys but also through the intestinal 

 tract. As first shown by BOCK and HOFFMANN and con- 

 firmed by KULZ'S and my own experiments, the intravenous 

 injection of rabbits with a sodium chloride solution of a some- 

 what higher concentration than the sodium chloride in the 

 blood brings about a transient excretion of glucose in the 

 urine. 1 The observations of MACCALLUM show that under 

 these conditions sugar is eliminated also by the stomach and 

 intestine and apparently in about the same concentration as 

 in the urine. The excretion of the carbohydrate through 

 the intestinal tract can be made more apparent by removing 

 the kidneys, but even when they are left intact, sugar is 

 nevertheless excreted to some extent through the alimentary 

 tract. How great a role this route of excretion plays in the 

 ordinary cases of human diabetes is an interesting question 

 which has not as yet been investigated. 2 



1 MARTIN H. FISCHER: University of California Publications, Physi- 

 ology, 1903, 1, pp. 77 and 87; PFLUGER'S Archiv., 1904, CVI, p. 80; ibid., 

 1905, CIX, p. 1. 



2 My analysis of the fseces in two cases of human diabetes failed 



