THE DIGESTIVE SYSTEM 279 



by eosinophile leucocytes which pass through the intestinal wall, 

 and become a part of the intestinal secretion. 



(2) Absorption of Fat. — While various other products of diges- 

 tion are absorbed by the intestine, the absorption of fat is the one 

 most easily observed and the one of most interest from the histological 



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Fig. 181. — Fat Absorption. Longitudinal section of villus of cat's small intestine, 

 three hours after feeding. X350. Osmic acid, a, Fat droplets in epithelial cells; i, 

 fat droplets in leucocytes in stroma; c, fat droplets in leucocytes within lacteal; d, fat 

 droplets free in lacteal; e, capillary containing blood cells; /, central lacteal of villus. 



standpoint because the passage of the droplets can be seen under the 

 microscope. After feeding fat, fatty acids, or soaps, fat globules are 

 found to have penetrated the intestinal mucosa, and may be-^'seen in 

 (a) the epithelial cells, (b) the leucocytes, and (c) the lacteals of the 

 villi (Fig. 181). Fat globules are never seen in the thickened free 

 borders of the cells. Hence it seems probable that the fat before 



