THE ABSORPTION OF THE FOOD-STUFFS 841 



ments made by Friedlander the absorptions of various proteins were 

 compared after their introduction into loops of the small intestine 

 which had been washed free from ferment. During a period of three 

 hours this author found that 21 per cent, of the proteins of egg white 

 or of blood serum were absorbed. During the same period, of 

 alkali -albumen which had been introduced into the loops, 69 per 

 cent, was absorbed. On the other hand, when syntonin and casein 



II 



III 



FIG. 350. Figures (from REUTER) showing changes in intestinal epithelium 

 induced by absorption of protein. 



I, epithelium of fasting rat ; II, initial stage ; III, later stage of protein 



absorption. 



were introduced into the intestine, no absorption whatever was 

 observed. As to the condition in which such unchanged protein 

 reaches the blood stream our knowledge is still imperfect. 

 Foreign proteins, such as egg albumin, or f he serum of other species 

 introduced into the blood stream, may cause poisonous effects, 

 and give rise to albuminuria, to lowering of blood pressure, or to 

 alteration of the coagulability of the blood. If injected in small 

 quantities they excite, as a reaction on the part of the organism, the 

 production in the blood serum of a precipitin, and the presence of 



