Nutrition Investigations. 267 



CYTASES IN HIGHER ANIMALS. 



There is at present no proof of the existence of cytases in any of the 

 higher animals. The literature on the subject has been exhaustively 

 reviewed by Bergmann (32), and Lohrisch (55, 56, 57) and it appears 

 that there is no cellulase in the saliva or pancreatic juice of swine, 

 horses, cattle, or sheep. The old observation by MacGillawry^ (cited 

 by Biedermann and Moritz(34) that a cytase can be extracted from 

 the vermiform appendix of the rabbit has been denied by Zuntz and 

 Degtiareff (88). Schmulewitsch's- statements (also cited by Bieder- 

 mann and Moritz) are worthless because he employed no antiseptics. 

 E. Miiller (61) found no sugar formed from the decomposition of cel- 

 lulose in the stomach of the goat, and Lusk (59) observed no increase 

 in sugar elimination after feeding a phlorhizinized dog 20 grams of 

 cauliflower, or a phlorhizinized goat 10 grams of paper. Lohrisch (57) 

 fed pure cellulose (5-20 grams) to a phlorhizinized rabbit and found 

 that it had no marked influence on the sugar output, and no nitrogen- 

 sparing effect. Scheunert (70) has made further investigation on the 

 action of the saliva and salivary glands in sheep, and confirms the 

 earlier experiments with the saUva of this animal. On the other hand, 

 Selliere (77) reports that the specially treated cellulose mentioned 

 above is converted into dextrose by the intestinal secretions of the 

 guinea pig in some instances. 



Practically nothing is known concerning the way in which cellulose 

 disappears from the alimentary tract of man. Schmidt and Loh- 

 risch (73) fed pure cellulose to diabetics and observed a disappearance 

 averaging 77.7 per cent, and no increase in the elimination of sugar. 

 They believe that most of it is absorbed in soluble form and not de- 

 stroyed by fermentation in the intestines. Lohrisch, having fed cel- 

 lulose in various diseases of the aUmentary tract,^ calls attention to 

 the fact that in constipation, where there is the least bacterial action, 

 the utiUzation of cellulose is highest, while in fermentation dyspepsia, 

 in which one might expect a marked disappearance, the utilization is 

 lowest. He therefore considers the digestion of cellulose as due at 

 least in part to enzymes. 



lArchiv Neerland, Vol. XI. 



^Uber das Verhalten der Verdauungssafte zur Rohfaser der Nahrungsmittel. 

 Bulletin de I'Academie Imperial de St. Petersburg, 1879. 

 'See results, p. 264. 



