0BGAN8 ANNEXED TO TSE ABDOMINAL DIGESTIVE CANAL. 423 



studied by Bernard and gchiff, and named " animal amidon ;" and, lastly, 

 adipose granules, whose volume and quantity vary with the condition of the 

 animals, or the period of digestion at which the liver has been removed. 

 The hepatic cells are situated in the network formed by the vessels of the 

 lobule, and constitute its principal portion. 



Hepatic Bucts. — Destined to carry away the bile secreted in the interior 

 of the hepatic lobule, the bili- 

 ary ducts form around it a kind '^ Fig. 212. E 

 of girdle that accompanies the 

 interlobular branches of the 

 vena portse. Within and with- 

 out, this girdle sends oif small 

 prolongments : the first bring 

 it into communication with 

 the ducts of the neighbouring 

 lobules; the second enter the 

 substance of the lobule and 

 are soon lost. 



The wall of the biliary 

 ducts is a thin amorphous 

 membrane, lined by polygonal 

 cells, smaller than the hepatic 

 cells. 



The origin of the hiliary or 

 hepatic ducts in the interior^f 

 the lobules is still a vexed 

 question in histology. It was 

 believed, and some authorities 

 still believe, that the ducts terminate in pouches, at a short distance from 

 the periphery of the lobule. But it has been remarked that an injection 

 introduced by the ductus choledochus does not remain near the periphery 

 of the lobule, but, on the contrary, penetrates to 

 its centre by passing between the hepatic cells ; and 

 from this it is admitted that the hepatic ducts fur- 

 nish a very fine network around each of the cellular 

 elements of the liver (Fig. 213). Nevertheless,_there 

 are histologists who do not share in this opinion, 

 who assert that these terminal ducts have no 

 proper walls, and that the supposed networks they 

 form is only a simple system of intercellular spaces 

 distended by the injection. 



Afferent vessels. — These are the branches of the 

 portal vein and hepatic artery. The portal vein, 

 after reaching the interior of the liver, divides into 

 gradually decreasing vessels, until it terminates by 

 forming the interlobular or subhepatic veins. _ These 

 vessels surround the lobule, communicate with the 

 neighbouring interlobular veins, and give off a large ,,,.,. 



number of twigs to the interior of the lobule, where a, Capilknes of the bihary 

 they anastomose, and constitute the hepatic capillary J"^^.^ ^ ducts rrcj 

 plexus. The hepatic artery furnishes ramuscules, piUary blood-ressels. 

 which mix with the ramifications of the portal vein 

 in the (va<nnal) plexus. The principal branches of the latter are all 



Portion of a hepatic column, showing its compo- 

 nent secreting cells ; B, Secreting cells detacheil ; 

 a, In their normal state ; b, A cell more highly 

 magnified, showing the nucleus and distinct oil- 

 particles ; c, In various stages of fatty degenera- 

 tion. 



Fig. 213. 



BILIARY CAPILLAEIE3 OP 

 THE babbit's LIVEE. 

 PART OF A LOBULE, 

 SHOWING THE ARRANGE- 

 MENT OF THE BILIARY 

 DUCTS IN RELATION TO 

 THE HEPATIC CELLS. 



