CH. XXXIII.] 



THE LIVER. 



499 



similar manner to the portal vein, its blood being returned by 

 small branches which pass into the capillary plexus of the lobules 

 which connects the inter- and mtfra-lobular veins. 



The hepatic duct divides and subdivides in a manner very like 

 that of the portal vein and hepatic artery, the larger branches 

 being lined by columnar, and the smaller by small polygonal 

 epithelium. 



The bile-capillaries commence between the hepatic cells, and 

 are bounded by a delicate membranous wall of their own. They 

 are always bounded by hepatic cells on all sides, and are thus 



Fig. 410. Sketches illustrating the mode of commencement of the bile-canaliculi within 

 the liver-cells (Heidenhaia, after Kupffer). A, rabbit' sliver, injected from hepatic duct 

 with Berlin blue. The intercellular canaliculi give off minute twigs which penetrate 

 into the liver-cells, and there terminate in vacuole-like enlargements. B, frog's liver 

 naturally injected with sulph-indigotate of soda. A similar appearance is obtained, 

 but the communicating twigs are ramified. 



separated from the nearest blood-capillary by at least the breadth 

 of one cell (figs. 408 and 409). 



To demonstrate the intercellular network of bile-capillaries, 

 Chrzonszezewsky employed a method of natural injection. A 

 saturated aqueous solution of sulph-indigotate of soda is introduced 

 into the circulation of dogs and pigs by the jugular vein. The 

 animals are killed an hour and a half afterwards, and the blood- 

 vessels washed free from blood, or injected with gelatin stained 

 with carmine. The bile-ducts are then seen filled with blue, and 

 the blood-vessels with red material. If the animals are killed 

 sooner than this, the pigment is found within the hepatic cells, 

 thus demonstrating it was through their agency that the canals 

 were filled. 



Pfliiger and Kupffer have since this shown that the relation 



K K 2 



