FECES. 521 



Feces. It is evident that the residue which remains after complete 

 digestion and absorption in the intestine must be different, both quali- 

 tatively and quantitatively, according to the variety and quantity of 

 the food. In man the quantity of excrement from a mixed diet is 

 120-150 grams, with 30-37 grams of solids, per twenty-four hours, while 

 the quantity from a vegetable diet, according to VoiT, 1 was 333 

 grams, with 75 grams of solids. With a strictly meat diet the excre- 

 ment is scanty, pitch-like, and black. The scanty feces in starva- 

 tion have a similar appearance. A large quantity of coarse bread yields 

 a great amount of light-colored excrement. In these cases the feces 

 are also habitually poorer in nitrogen than after food rich hi protein. 

 The individuality also plays an important role in the utility of the food 

 and the formation of feces (ScmERBECK 2 ). If there is a large propor- 

 tion of fat, it takes a lighter clay-like appearance. The decomposi- 

 tion products of the bile-pigments seem to play only a small part in the 

 normal color of the feces. 



The constituents of the feces are of different kinds. In the excre- 

 ment are found digestible or absorbable constituents of the food, such 

 as muscle fibers, connective tissues, lumps of casein, grains of starch, 

 and fat, which have not had sufficient time to be completely digested 

 or absorbed in the intestinal tract. In addition the excrement con- 

 tains indigestible bodies, such as the remains of plants, keratin sub- 

 stances, and others; also form-elements originating from the mucous coat 

 and the glands; constituents of the different secretions, such as mucin, 

 cholic acid, dyslysine, and cholesterin (koprosterin or stercorin), purine 

 bases, 3 and enzymes; mineral bodies of the food and the secretions; 

 and, lastly, products of putrefaction or of digestion, such as skatol, indol, 

 volatile fatty acids, purine bases, lime, and magnesia soaps. Occasion- 

 ally, also, parasites of different kinds occur; and lastly, the excrement 

 contains micro-organisms of various species. 



That the mucous membrane of the intestine by its secretion and by 

 the abundant quantity of detached epithelium contributes essentially 

 to the formation of feces follows from the discovery first made by L. 

 HERMANN and substantiated by others, 4 that a clean, isolated loop 



1 Zeitschr. f . Biologie, 25, 264. 



2 Arch. f. Hygiene, 51. 



3 In regard to the purine bases in feces, see Hall, Journ. of Path, and Bacteriol., 

 9; Schittenhelm, Arch. f. klin. Med., 81. Schittenhelm and Kruger, Zeitschr. f. physiol. 

 Chem., 45. 



4 Hermann, Pfliiger's Arch., 46. .See also Ehrenthal, ibid., 48; Berenstein, ibid., 

 53; Klecki, Centralbl. f. Physiol., 7; 736, and F. Voit, Zeitschr. f. Biologie, 29; v. 

 Moraczewski, Zeitschr. f. physiol. Chem., 25; F. Lippich; Prager med. Wochenschr., 

 32. 



