REACTION OF LYMPHATIC ENDOTHELIUM 445 



the theory, based upon his observations of the reversible action 

 of Hpase, that the neutral fat, present in the intestinal cells 

 during fat absorption, represented merely a stable phase in the 

 reaction and that the absorbed fat was continually leaving the 

 intestinal cells and entering the lymphatics in a soluble form, 

 probably fatty acids, and was resynthesized somewhere in the 

 'ymphatic system (Loevenhart had previously shown that lipase 

 is present in the lymph and the lymph glands). B. Moore (21) 

 questions this hypothesis on the basis of analyses which showed 

 that practically all the fat in the lacteals during absorption exists 

 "n the form of neutral fat, while the intestinal mucosa, from the 

 same animals, yields a much larger amount of fatty acids. 



For many j^ears, investigators, who have studied this question 

 by histological methods, have described leucocytes as taking 

 part in fat absorption. Thus, Zawarkyn (29) in 1883 found many 

 leucocytes present in the intestinal villi, during fat absorption, 

 containing granules which stained with osmic acid. In 1885, 

 Schilfer (27) described similar cells as playing an important role 

 in the process of fat absorption. His theory was that leuco- 

 cytes, loaded with fat, entered the central lacteals and there dis- 

 integrated and set free the fat. Rachel Zipkin (30), in studying 

 the histology of the intestine in the monkey, found many phago- 

 cytic cells, closely adherent to the wall of the central lacteals 

 of the intestinal villi. D'Errico (7) describes large numbers of 

 leucocytes containing fat in his experiments in which he ligated 

 the thoracic duct during intestinal absorption. Kischensky (16), 

 in studying the intestinal epithelium in preparations stained with 

 Scharlach R and osmic acid, found many finely divided droplets 

 inside the epithelial cells, during fat absorption, and also be- 

 tween the cells. He also found fat within leucocytes during fat 

 absorption in young kittens. In these cases the fat was present 

 chiefly in small round cells with large nuclei and was seldom 

 found in polymorpho-nuclear leucocytes. This last point is of 

 interest in connection with the work of Fiessinger and Marie (10) 

 on exudates, which has been referred to earlier in this article, in 

 which they demonstrated the presence of lipase in lymphocytes 

 and showed that the polymorpho-nuclear leucocytes contain a 



