DIGESTIVE GLANDS. 



227 



gland, thus differs from all other glands (i), that the 

 secreting tubules anastomose, and (2) that the wall 

 of the secreting portions consists of but two cells. 



The liver cells 

 have no cell wall. 

 They are large poly- 

 hedral or irregular 

 epithelial cells, con- 

 taining sometimes 

 two, but usually one, 

 nucleus. The cyto- 

 plasm is granular, 

 containing bile drops 

 and vacuoles. The 



Inlracellular bile passage. 



Intercellular bile 

 duct. 



chief function of 

 these cells is twofold 



Fig. 173. Diagram of liver cells, show- 

 ing bile passages. 



(i) to secrete bile into the bile 



Intercellular bile duct. 



Intracellular bile 

 passage. 



capillaries, and (2) receive and contribute sugar to the 

 blood capillaries. In junction with this it is affirmed 



that definite cyto- 



Biood capillary. plasmic or intracellu- 



lar channels exist, 

 particularly for the 

 passage of bile. 

 These channels end 

 in minute dilatations 

 within the cells, from 

 which finer passages 

 lead to and arborize 

 around the nucleus. 

 According to some 



investigators, the finer passages may penetrate the 

 nucleus and are then called intranuclear canals. 



Blood capillaries. 



Fig. 174. Diagram of liver cells, 

 showing bile ducts and blood capillaries. 



