532 DIGESTION. 



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 diges- 

 tion 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. 1 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 

 digestion fluids act substitutingly. In this regard ZUNZ and MAYER 2 

 found that in dogs (meat digestion) the tying of the pancreatic passages 

 is essentially compensated for by an increased secretion of pepsin and 

 other proteolytic enzymes, and that in this case the demolition of the 

 protein in the stomach goes further than in a normal animal. 



The carbohydrates are, it seems, chiefly absorbed as monosaccharides. 

 Glucose, fructose, and galactose are probably absorbed as such. The 

 two disaccharides, saccharose and maltose, ordinarily undergo an inver- 

 sion in the intestinal tract and are converted into glucose and fructose. 

 Lactose is also, at least in certain animals, inverted in the intestine. 

 In other mature animals, on the contrary, if the lactase formation is not 

 excited by milk food, the sugar is not inverted or only to a slight 

 extent (VoiT and LUSK, WEINLAND, PORTIER, ROHMANN and NAGANO), 

 and it probably is absorbed as such in these animals if it does not under- 

 go fermentation, or, as ROHMANN and NAGANO 3 assumed, if it is not 

 transformed in the intestinal mucosa in some unknown way. An 

 absorption of non-inverted carbohydrates is not improbable, and accord- 

 ing to OTTO and v. MERING the portal blood contains, after a carbo- 

 hydrate diet, besides glucose, a dextrin-like carbohydrate. MoscATi 4 



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

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

 Zeitschr. f. Biologic, 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; 

 See also Brugsch and Pletnew, Zeitschr. f. exp. Path. u. Therap. 6, 326. 



2 Mem. de 1'acad. roy. de me"dic. de Belg., 18. 



3 Voit and Lusk, Zeitschr. f. Biologic, 28; Rohmann and Nagano, Pfliiger's Arch., 

 95, which contains the references to the literature. 



4 Otto, see Maly's Jahresber., 17; v. Mering, Arch. f. (Anat., 4.) Physiol., 1877; 

 Moscati, Zeitschr. f. physiol. Chem., 50 



