713 
duct and the margin of the adjacent lobule, and occasionally form 
anastomoses with each other, but these junctures are not seen so 
frequently as with the vascular system. Quite frequently little twigs 
may be seen coming off from a stem and running quite close to the 
outer edge of the columnar epithelium, and ending there in a ball- 
shaped termination, just at the point where the cement substance -se- 
parates two of the epithelial cells. A little less frequently the ending 
is not so distinct, the nerve twig becomes very fine, and beyond its 
clearly defined point, are situated a number of extremely minute black 
dots, which continue in the line of the nerve fibre, and apparently 
enter for some short distance the cement substance between two cells, 
where they are lost without defined ending. Accordingly, it is prob- 
able that the extremities of the fibres enter between the columnar 
cells, and there end in some fine pointed termination that is not suf- 
ficiently well stained to be visible under the microscope (fig. 5). Be- 
sides these endings close to the epithelial cells, there are other globular 
endings lying just along the outer margin of the bile duct, where the 
thin band of unstriped muscular fibres lie, and though these fibres 
are not to be seen by this method of staining, it is extremely prob- 
able that the nerve influence of these endings is directed toward 
supplying them with the power of temporarily contracting the bile 
duct and expelling its contents. Branches of the biliary-duct nerves 
also pass off into the intra-lobular structures, and terminate between 
the hepatic cells, usually with the common ball-shaped ending (fig. 6). 
As has already been shown, the nerves accompanying the portal 
veins, hepatic arteries, and biliary ducts, unite in forming an intra- 
lobular plexus, which has the same general arrangement and contour 
as the bile capillaries, and runs upon and with them, and from their 
comparative fineness, and the comparative coarseness of the capillaries, 
they are not usually visible even in the best stained sections. Here 
and there, however, a break occurs, the bile capillaries, probably from 
their containing no biliary fluid, are no longer stained; and portions, 
or the whole of a plexus become visible. Pictures like fig. 10 are 
not in the least uncommon in well tinged specimens, but a complete 
‘plexus like fig. 9, is met with extreme infrequency, having oc- 
curred, well defined only three times in some 500 sections that were 
carefully examined. Usually they could be traced directly by a single 
filament to the fibres surrounding the central portal vein. The single 
fibre would split up again and again, and form a meshwork between 
the liver cells, giving no evidence of any actual termination within its 
