187 
Figs. 16 and 17. Central columnar biliary capillaries, showing relations to the 
liver cells, 16, central end, 17, more distal portion. V intra-lobular capillary. 
Fig. 18. The gall capillaries surrounding two liver cells with immersion systems, 
showing the apparent penetration of the short diverticulae into the cellular substance. 
Fig. 19. Various forms of the perivascular cells of the rabbit’s liver. 1 to 12 me- 
dium sized and smaller cells. 8 granular cell, showing the relation to the capillary wall 
on transverse rection. 12—13 types of the larger granular cells. 
Fig. 20. Drawing showing the relation of the capillary, perivascular cell, and the 
hepatic columns. 
Fig. 21. Transverse section showing granular cells in space left between the hepatic 
cells by their irregular conformation. 
Fig. 22. Very greatly enlarged and semi-diagramatic drawing of two of the short 
diverticulae, with the cup-shaped endings of the inner portion. 
Figs. 13, 14, 15, 21, 22 were drawn with the aid of a Zeiss homogeneous im- 
mersion 1—12, ocular 4; the others with objective E, ocular 4. 
nermost extremity of each and all of them may be seen an infinites- 
simally short projection, which is thinner and more transparent than 
the hinder portion. This has apparently a cup-shaped termination 
(fig. 22), and is accordingly not a blind ending, but is possessed of a 
lumen into which is poured the biliary fluid secreted by the cell lying 
adjacent to it. The fine diverticulae and cup endings, are best 
studied in the canals of the polygonal plexus, where in the series of 
canals surrounding a single cell, from fifteen to thirty, or even more 
of these final terminations may be observed. 
No appearance of a membrane to the biliary capillaries in pre- 
parations made by this method is to be found, yet it is hardly reason- 
able that such very definite rounded forms as they always present, 
studded with diverticulae and irregular branches can be mantained 
without the aid of an encompassing membrane, their very constant 
and similar appearance precludes the non-existence of it, and above 
everything else, the gradual enlargement from a minute capillary to 
the large marginal canaliculi, and their final continuance into the 
biliary ducts, would indicate that there was a continuous membrane 
which extended from the inner lining of the duct to the marginal 
network, and through it to the finer capillaries and blind terminations 
on the cells nearest to the central portal veins of the lobules. 
Ill. The Perivascular Cells of the Rabbits Liver. 
Both the rapid Gorcı and picric-acid-silver methods, show scat- 
tered yellowish granular bodies lying between the liver cells and the 
adjacent vascular walls that are not visible by ordinary methods of 
treatment. At first, we considered these granular masses as appearing 
prominently, because of some unhealthy condition of the organ in pro- 
cess of examination, but finding them in livers free from all trace of 
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