STRUCTURE OF THE BILIARY DUCTS. 



877 



throughout each lobule, injected blue, while the intervening cells remained 

 free from colour. These canals he describes as of regular diameter, without 

 increase of size where they anastomose, and by teasing he obtains portions 

 of them with distinct walls standing out free from the cells : by warming 

 the section to 113 Fah., the blue colour is destroyed while the canals still 

 remain visible. By killing the animals sooner after the injection, the 

 blue colouring matter was found within the hepatic cells, thus demonstrating 

 that it was through their agency that the canals were filled. Further expe- 

 riments were made in animals in which the portal vein and hepatic artery 

 had been tied, and the result obtained was that, when the hepatic artery 



Fig. 615. Two SMALL FRAGMENTS OP HEPATIC LOBULES, OF Fig. 615. 



WHICH THE SMALLEST INTERCELLULAR BlLIARY DtJCTS WEEK 

 FILLKD WITH COLOURING MATTKR DURING LlFE, HIGHLY 



MAGNIFIED (from Chrzonszczewsky). 



In A, the hepatic cells have been separated, and the inter- 

 cellular ducts, , are seen not only passing between them, 

 but also in part projecting free ; in this preparation the 

 colour was discharged by heat : in B, the colouring matter 

 remains in the ducts, and the cells are more closely con- 

 nected together. 



had been tied, the peripheral parts of the lobules 

 showed the blue canals, while the centre of each 

 was left colourless ; and that, when the portal vein 

 had been tied, the reverse effect was produced ; 

 the centre of each lobule showing blue canals, while 

 in the intervening spaces only larger ducts were 

 seen. It is worthy of remark that the appearance 

 of fibres crossing the capillary spaces observed by 

 Henle in sections washed with alkali, might very 

 well be due to such canals as those described by 

 Budge, Chrzonszczewsky, and others. 



Structure of the ducts. The bile-ducts have strong distensible areolar 

 coats, containing abundant elastic tissue, and their mucous membrane is 

 lined with columnar epithelium. The minute ramifications between the 

 lobules have walls of a more homogeneous nucleated tissue, but the lining of 

 columnar epithelium is still found in them (Henle). The mucous membrane 

 of those which are less minute presents numerous openings, which are scat- 

 tered irregularly in the larger ducts, but in the subdivisions are arranged in 

 two longitudinal rows, one at each side of the vessel. These openings were 

 formerly supposed to be the orifices of mucous glands ; but, while the main 

 ducts are studded with true mucous glands of lobulated form and with 

 minute orifices, the larger openings now referred to belong, as was pointed 

 out by Theile, to sacs and ramified tubes which occasionally anastomose, 

 and may be studded all over with caecal projections. Sappey and Henle, 

 who have made these processes the subject of special investigation, find 

 that they are so numerous as sometimes to conceal the parent tube, and 

 on this Henle bases his suggestion (System. Anat.) that they are engaged in 

 the secretion of the bile. 



Aberrant biliary ducts. In the duplicature of the peritoneum forming 

 the left lateral ligament of the liver, and also in the two fibrous bands 

 which sometimes convert the fossa for the vena cava and the fissure of the 

 umbilical vein into canals, there have been found biliary ducts of considerable 



