204 



THE BILE. 



Fig. 68. 



surrounded by a single sheath of such glandular cells, which stand in 

 place of the epithelial lining of a tube or follicle. 



In the liver of the warm-blooded quadrupeds, the texture of the organ 

 is more compact, the glandular cells and capillary bloodvessels more 

 closely united, and especially the finest biliary passages in the substance 

 of the lobule are more abundant and inosculate more frequently with 

 each other. From the plexus of biliary canaliculi upon the surface of 

 the lobule, already described, branches of much smaller size penetrate 

 into its interior, and these inosculate so abundantly by transverse com- 

 munications that they encircle each glandular cell in the meshes formed 

 by their network. These interior communicating passages are the capil- 

 lary bile-ducts. They are much smaller than the capillary bloodvessels, 

 being in the rabbit's liver, according to Kolliker, not more than 2 mmm. 

 in diameter, regularly cylindrical in form, and without any perceptible 

 dilatations at the points of inosculation. They embrace the glandular 

 cells in such a way that they are always situated at the greatest possible 

 distance, that is, half the diameter of a cell, from the nearest capillary 

 bloodvessel ; the bloodvessels running along the borders or angular 

 edges of the prismatic cells (Kolliker), while the capillary bile-ducts 

 pass along the middle of their plane surfaces. Thus, the two sets of 



canals, namely, capillary blood- 

 vessels and bile-ducts, form a 

 double series of inosculating 

 passages embracing the gland- 

 ular cells, the meshes of which 

 are always directed nearly or 

 quite at right angles to each 

 other. 



The intralobular capillary bile 

 ducts, above described, as de- 

 monstrated by injections, have 

 been regarded by some authori- 

 ties as artificially produced by 

 the accidental extravasation of 

 the injection fluid and its infiltra- 

 tion between the glandular cells. 

 But the existence of these ducts 

 as a natural formation has been 

 corroborated by too many ob- 

 servers to leave it a matter of 

 doubt, especially considering the 

 regular and uniform arrange- 

 ment under which they present themselves. Their situation is also 

 against the hypothesis of their artificial origin, since they are not placed 

 at the angular borders of the glandular cells, where an extravasated 

 fluid would naturally find its way, but run along the middle of their 

 plane surfaces where they lie in close contact with each other ; and. 



SECTION OP PART ov A 



L.OBULE PROM THE RABBIT'S LlVER. 



a, 0,0. Nucleated glandular cells. b,b,b. Capil- 

 lary bile-ducts passing between the adjacent 

 cells. c,c,c. Sections of capillary bloodvessels. 

 (Genth.) 



