278 PATHS OF ABSORPTION FOR PROTEIDS. 



With reference to a possible correspondence between lymph 

 flow and urea excretion after proteid absorption it may be 

 remarked that according to Tschlenoff if peptone is in- 

 gested instead of ordinary proteids, the maximum urea excretion 

 is reached in the second hour. To emphasize the comparison 

 as Asher and Barbera have done between the lymph flow 

 and the urea excretion observed in quite different experiments 

 seems to me of doubtful value ; for the lymph flow is readily 

 influenced by purely mechanical factors. Thus it is quite 

 possible that, in my experiment, movements of defecation ob- 

 served in the dog in the sixth hour may explain the increased 

 flow of lymph unaccompanied by any alteration in the percent- 

 age of proteids ; just as slight pressure on the abdomen will 

 immediately cause an increase in the flow. 



Asher and Barbera * have formulated the theory that the 

 lymph is a product of metabolism in the glands of the body, 

 and they have attempted to demonstrate that the lymph flow 

 increases in all cases where there is accelerated glandular 

 activity. In view of the work accomplished by the alimentary 

 epithelium and the liver during the digestion and absorption 

 of proteids, the new theory demands that an increased flow of 

 lymph should result after proteid feeding. The present ex- 

 periment with " pepton " failed to yield results in conformity 

 with this view ; it might, however, be said by the defenders 

 of the theory that no pronounced increase in lymph flow is 

 to be expected during the absorption of soluble and readily 

 diffusible products like Witte's " pepton," since the work of the 

 intestines is comparatively slight under these conditions. Such, 

 at least, is the explanation which they have applied to the 

 absence of accelerated lymph flow in carbohydrate nutrition. 



The results of the absorption experiment with moderate quan- 

 tities of a soluble proteid fail to modify the current statements 

 regarding the paths by which proteids are absorbed ; t. e., under 

 ordinary circumstances by far the greater share in the process 

 must still be delegated to the capillaries of the villi. 



* Asher and Barbara: Zeitschr. f. Biologie, 1898, xxxri, p. 210; Asher, 

 IV. International Physiological Congress, CentralbL f. Physiol., 1898, xii, 

 p. 486. 



