35° VESSELS OF THE LIVER. [sect. 1 62. 



the canals. What Weber thus describes as vasa aberrantia, were subsequently 

 described by TJieile as glands of the biliary ducts. On the other hand, L. 

 Beale has not only adopted Weber's opinion on these structures, but goes 

 so far as to regard all the reputed mucous glands of the hepatic ducts as 

 parts of the biliary canals. 



The bile is normally quite fluid, and contains epithelial cells only as an 

 accidental mixture from the larger gall-ducts. Liver-cells never occur in 

 it, and a.re only accidentally and in few instances met with in the smaller 

 ducts (Wharton Jones, L. Beale). Constituents which, though abnormal, 

 are very frequent, are — fat-globules, colouring matter of the bile in the 

 form of granules or granular masses, which, as in the hepatic cells, are 

 separated in considerable quantities, in the bile itself, under certain cir- 

 cumstances. With these there are to be ranked, but of more rare occurrence, 

 crystals of cholesterine, and especially the reddish needles of bilifulvin, which 

 were very recently observed by Yirchow. According to Virchow, the epi- 

 thelial cells of the gall-bladder have the same structure as those of the 

 small intestine, and are also often found filled with fat, which, as Vircliow 

 supposes, has been absorbed from the bile (Virch. Arch., LXI.*). 



§ 162. Vessels and Nerves of the Liver. — The liver is alto- 

 gether singular in respect of its blood-vessels, inasmuch as, besides 

 an artery and a returning vein, it possesses an afferent vein, the portal 

 vein. Whilst the latter vessel supplies, properly speaking, the 

 secreting parenchyma, and is by the capillary network there 

 situated directly continued into the hepatic veins, the artery is 

 destined more for the nourishment of the walls of the bile-ducts, 

 the portal vein itself, the capsule of GUsson, and the serous in- 

 vestment of the liver, and takes only a subordinate share in the 

 formation of the capillary network of the hepatic islets. The 

 ramifications of the portal vein, and of some small veins of the 

 gall-bladder, and of the stomach (see Weber, Ann. Acad., II., 

 1845), which pass into the liver separately, generally take place 

 dichotomously ; still, besides the main branches into which they 

 divide, a number of smaller vessels pass off at right angles, both from 

 the largest and from the somewhat smaller branches. These vessels, 

 passing off at right angles, betake themselves, often immediately, 

 often after a very short course, to the hepatic islets, which 

 bound the principal vascular canals ; whilst the portal branches, 

 all becoming more and more branched and attenuated, have to run, 

 for a greater or less distance according to their diameter, through 

 liver-parenchyma in the vascular canals, lined by the capsule of 

 GUsson, before they proceed to the hepatic islets or lobules. Each of 

 these receives from the one or the other order of portal branches at 

 least 3, mostly 4 or 5 small vessels, j^V" to -fa'" in diameter, which 

 Kiernan calls venai interlobular es ; still, such a vein never supplies 



