STRUCTURE OF THE INTESTINE. 



171) 



Since the lymph-cells are amoeboid, it is probable from these facts 

 that the mechanism of fat absorption in these cases consists of the fol- 

 lowing processes viz. (1) absorption of fat into the columnar epi- 

 thelium-cells of the surface ; (2) inception of fat by the lymph- 

 corpuscles in the epithelium, these taking it up after it has passed 

 through the epithelium-cells ; (3) migration of the lymph -corpuscles 

 carrying the incepted fat-particles by their amoeboid movements 

 through the tissue of the villus and into the central lacteal ; (4) 

 disintegration and solution of the immigrated lymph-corpuscles, and 

 setting free both of their fatty contents and also of the proteid matters 

 of which they are themselves composed. 



This migration of the lymph-corpuscles into the lacteals of the villi 

 is not a special feature of fat-absorption alone, but occurs even when 

 A 



sir 



cp 



FIG. 210. SECTION OF THE VILLUS OF A RAT KILLED DURING FAT- ABSORPTION. 



ep, epithelium ; sir, striated border; c, lymph-cells : c', lymph-cells .in the epithelium; 

 I, central lacteal containing disintegrating lymph-corpuscles. 



FIG. 211. Mucous MEMBRANE OF FROG'S INTESTINE DURING FAT- ABSORPTION. 

 ep, epithelium ; str, striated border ; c, lymph-corpsucles ; I, lacteal. 



absorption of other matters is proceeding ; so that the 'transference of 

 fat-particles is merely a part of a more general phenomenon accompany- 

 ing absorption. 



THE LARGE INTESTINE. 



The large intestine has the usual four coats, except near its termina- 

 tion, where the serous coat is absent. The muscular coat is peculiar in 



