294 PHYSIOLOGY OF ALIMENTATION. 



the cells once more in the empty condition in which they 

 were found at the beginning of the digestion period. 



Under the influence of the lipase they contain, the tissues 

 of the body also store fat when it is plentiful in the food and 

 give it up during starvation in the same manner as the epithe- 

 lial cells of the intestinal mucosa ; but a discussion of this 

 problem is beyond the limits of our subject. One more fact 

 is of interest in support of the ideas of fat absorption ad- 

 vanced above. We would expect from chemical considera- 

 tions alone that if a certain fat is digested by lipase, the 

 products of its digestion should, when synthesized under the 

 influence of the same ferment, yield the original fat, and 

 that this ought to hold when different kinds of fat are con- 

 sumed by animals. Not only were MUNK and ROSENSTEIN 

 able to isolate from the lymph obtained from their patient 

 with a lymphatic fistula an oily fat when olive-oil was fed, 

 and a tallow-like fat when mutton-tallow was administered, 

 but ROSENFELD l has been able to show~more recently that if 

 one dog is fed cocoa-butter and another mutton-tallow the 

 fats deposited in each case correspond to those ingested. 

 Goldfish and carp, moreover, deposit mutton-tallow when 

 this is fed to them. 



Unlike the absorption of the carbohydrates and the pro- 

 teins, which leave the alimentary tract with the blood stream, 

 the fats leave the absorptive mucous membrane almost en- 

 tirely by way of the lymph. Very shortly after a fatty meal 

 the lymph leaving the intestine assumes a milky appearance, 

 owing to the exceedingly fine droplets of fat contained in it, 

 and at the height of absorption may contain from 3 to 8 per- 

 cent of fat. The lymph returning from the intestine and 

 thus laden with fat is known as chyle. MUNK and ROSEN- 

 STEIN found that more than 60 percent of the fat consumed 

 by their patient with a lymphatic fistula could be recovered 

 from the lymph within the first twelve hours after feeding. 



1 ROSENFELD: Verhandlungeu d. XVII. Congress f. innere Medicin, 

 1899, p. 503. 



