8 E. A. Schäfer, 



of the intestine by tlie columnar epitlielium cells; that tliey 



are transmitted in some way from these to tlie amoeboid lymph- 



cells and that these again convey them to and discharg-e them 



into the central lacteal." 



I have quoted the description of these methods and their results 



at length, partly because so far as it goes it still furnishes as accurate 



an account as any new one I could give of the process of fat ab- 



sorption in the villi as exemplified by histological preparations, partly 



because the same facts, based upon observations made by identically 



the same methods, have within the last few months been announced 



by another physiologist in ignorance of the observations above quoted.') 



Since Publishing those results I have had abundant opportunity in the 



course of my practical teacliing to confirm the facts then recorded, 



and in addition to this I have within the last year or two been ac- 



tively engaged in studying again the question of the mode of ab- 



sorption not only of fat but of other alimentary substances. It is 



with some of the results of these more recent investigations that I 



propose to deal. 



The Columnar Epitlielium during absorption. 



The cell-body of the columnar epithelium cell is composed ot 

 soft protoplasm unenclosed by a membrane: the sharply marked line 

 which is sometimes seen in sections of the hardened tissue marking 

 off the epithelium cells from one another, being an optical effect due 

 to the juxtaposition of two prismatic columns. The examination of a 

 fresh, teased preparation conclusively proves the absence of any cell- 

 membrane. That the cell-body is soft and yielding is proved by the 

 fact that the semifluid protoplasm of the leucocytes which occur 

 amongst the columnar cells is able to indent it:'') hence if there are 

 many such cells in the epithelium, the cells of this tissue, after being 

 hardened in chromic or osmic acid and subsequently separated by 

 teasing or otherwise, often exhibit jagged margins as the result of 



Zawarykin, Pflüger's Archiv. Bd. XXXI, p. 231. 



^) Compare Watney, On the minute anatomy of the alimentary canal, Phü. 

 Trans. 1876, p. 460. 



