THE LIVER. 



289 



suggested that the fat is split up by the pancreatic juice into glycerin 

 and fatty acids, and that the fatty acids are then dissolved by the 

 bile and the alkalies of the intestinal juice, only again to combine 

 with the glycerin to form fat within the epithelial cells. It remains 

 for the histologist to ascertain the exact mechanism in the cell which 

 changes the fatty acids into fat. Altmann (94) claims that certain 

 granules of the cells (elementary organisms) offer a solution to this 

 problem. The manner in which the fat globules gain access to the 

 lacteal vessels of the villi is a question which has not as yet been 

 settled definitely ; it would appear, however, that the leucocytes 

 play an important part in this transfer, since in preparations of the 

 intestinal mucosa, taken from an animal fed on a diet rich in fat 

 milk diet and stained in osmic acid, numerous leucocytes contain- 

 ing black granules or globules may be observed in the lacteal 

 vessels and in the spaces of the adenoid reticulum of the villi. 



D. THE LIVER. 



In the adult the liver is a lobular, tubular gland with anastomos- 

 ing tubules. When viewed with the unaided eye or under low 

 magnification the liver is seen to be composed of a large number 



Intralobular 

 vein. 



Branch of 



portal vein. 

 Bile-duct, 



Branch of 



hepatic 



artery. 

 Interlobular 



connective 



tissue. 



Fig. 227. Section through liver of pig, showing chains of liver-cells ; X 7- 



of nearly spheric divisions of equal size ; this is particularly notice- 

 able in some animals, especially in the pig. These divisions are the 

 liver lobules and have a diameter of from 0.7 to 2.2 mm. They are 

 separated from each other by a varying amount of interlobular con- 

 nective tissue, which is a continuation of the capsule of Glisson, a 

 fibro-elastic layer surrounding the entire liver and covered for the 

 greater portion by a layer of mesothelium. In the interlobular 

 septa are found the larger blood-vessels, bile passages, nerves and 

 19 



