508 DIGESTION. 



gen through the feces amounted to 22-48 per cent. Experiments with 

 other vegetable foods, and also the investigations of SCHUSTER, CRAMER, 

 MEINERT, MoRi, 1 and others on the utilization of foods with mixed 

 diets, have led to similar results. With the exception of rice, wheat 

 bread, and certain very finely divided vegetable foods, it is found in gen- 

 eral that the nitrogen deficit by the feces increases with a larger quan- 

 tity of vegetable material in the food. 



The reason for this is manifold. The large quantity of cellulose 

 frequently present in vegetable foods impedes the absorption of pro- 

 teins. The greater irritation produced by the vegetable food itself or 

 hy the organic acids formed in the fermentation in the intestinal canal 

 causes a more violent peristalsis, which drives the contents of the intes- 

 tine faster than otherwise along the intestinal canal. Another and most 

 important reason is the fact that a part of the vegetable protein substances 

 seem to be indigestible, and because of the difficultly digestible vegetable 

 food, a large quantity of digestion fluids containing nitrogen are secreted. 



In speaking of the functions of the stomach we stated that after 

 the removal or excision of this organ, an abundant digestion and absorp- 

 tion of proteins may take place. It is therefore of interest to learn how 

 the digestion and absorption of proteins go on after the extirpation of 

 the second protein-digesting organ, the pancreas. In this connection 

 there are the observations on animals after complete or partial extirpa- 

 tion of the gland by MINKOWSKI and ABELMANN, SANDMEYER, V. HAR- 

 LEY, after destroying the gland by ROSENBERG, and also in man after 

 closing the pancreatic duct by HARLEY and DEUCHER. In all these 

 cases such discrepancy of figures has resulted for the utilization of the 

 proteins between 80 per cent after the apparently complete exclusion 

 of pancreatic juice in man (DEUCHER) and 18 per cent after extirpa- 

 tion of the gland in dogs (HARLEY) that one can hardly draw any 

 clear conception as to the extent and importance of the trypsin 

 digestion in the intestine. That on completely preventing the entrance 

 of pancreatic juice only a slight diminution in the protein absorption 

 takes place follows from the researches of LOMBROSO and NiEMANN. 2 

 In order to understand in these cases why the digestion and absorption 

 took place so abundantly it would be of interest to know how other diges- 



1 Rubner, Zeitschr. f. Biologie, 15; Meyer, ibid., 7; Hultgren and Landergren, 

 Nord. med. Arch., 21; Schuster, in Voit's "Untersuch. d. Kost," etc., 142; Cramer, 

 Zeitschr. f. physiol. Chem., 6; Meinert, "Ueber Massennahrung," Berlin, 1885; Kell- 

 ner and Mori, Zeitschr. f . Biologie, 25. 



2 Abelmann, " Ueber die Ausniitzung der Nahrungsstoffe nach Pankreasexstirpa- 

 tion" (Inaug. -Dissert. Dorpat, 1890), cited from Maly's Jahresber., 20; Sandmeyer, 

 Zeitschr. f. Biologie, 31; Rosenberg, Pfliiger's Arch., 70; Harley, Journ. of Pathol. 

 and Bacteriol., 1895; Deucher, Correspond. Blatt. f. Schweiz. Aerzte, 28; Lombroso, 

 Arch. f. exp. Path. u. Pharm., 60; Niemann, Zeitschr. f. exp. Path. u. Therap., 5. 



