176 FUNCTIONS OF NUTRITION. 



In the amphibia (frogs and water-lizards), as shown by Hering and 



FIG. 27. 



I\ 



FINER BILIARY CANALS AND BILIARY DUCTS, from the frog's liver. a. Small biliary duct, with 

 its lining of epithelium cells, ft, c. Terminal branches of the minute biliary canals, surrounded 

 by glandular cells, d. Transverse communicating branch between two biliary canals. e,e. Sheath 

 of glandular secreting cells, surrounding the biliary canals /. Section of capillary blood-ves- 

 sel. (Eberth.) 



Eberth (Fig. 27), the ultimate structure of the liver is not essentially 



different from that of other lobu- 

 lated glands. The smaller biliary 

 ducts, lined with pavement epi- 

 thelium, give off minute branches 

 which communicate with each 

 other and are in contact every- 

 where with the large glandular 

 cells ; each terminal branch being 

 surrounded by a single sheath 

 of such cells, representing the 

 epithelial lining of a tube or 

 follicle. 



In man and the warm-blooded 

 quadrupeds, the texture of the 

 liver is more compact, the gland- 

 ular cells and capillary blood-ves- 



TRANSVERSE SECTION OF PART OF A LOBULE sels more closely united, and espe- 

 FROM THE BABBIT'S LIVER. a, a, a. Nucleated p : fl ]i v f u p fi np c;t biliarv r>assao-es 

 glandular cells, b, b, b. Capillary bile-ducts pass- Ciall 7 tne 



ing between the adjacent ceils. c,c,c. Sections within the lobule are more abun- 

 dant. From the plexus of cana. 



liculi on the surface of the lobule, smaller branches penetrate its inte- 

 rior, and there inosculate so frequently, that they encircle each gland- 



