66 
Proceedings of Royal Society of Edinburgh. [sess. 
erythrocytes, demonstrate that the cells must he in communication 
with the hepatic capillaries. The exact nature of such communica- 
tion is not determined, but Professor Browicz goes on to show that 
the connection of the liver cells with the blood capillaries is much 
more intimate than has been generally supposed ; that the peri- 
vascular lymphatics which have been described by M‘Gillivray and 
others as encircling the lobular blood capillaries in all probability 
do not exist ; and that some of the cells which form the walls of 
those capillaries resemble the liver cells in containing biliary 
products in vacuoles, and in minute channels, and display pro- 
jections which penetrate into the cytoplasm of the adjacent liver 
cells. The inference which he draws from these observations is 
thus expressed by him*: — “All these circumstances compel the 
conclusion that in addition to the intracellular biliary passages, 
which act as excretory channels, there must also exist special 
afferent nutritive channels, or canaliculi, in the liver cells. That 
these cannot be made visible as a system of canaliculi is no draw- 
back to this conclusion. The intracellular canaliculi must in any 
case be exceedingly fine, and could only, under the most favour- 
able circumstances, be here and there visible, considering the very 
small amount of nutritive and functional material which has at 
any one time to pass into a liver cell ; the microscopic appearance 
is in fact only a snap-shot.” 
I am, I believe, in the position of being able to offer the objec- 
tive proof of this important deduction. In specimens of injected 
liver of the rabbit which we possess in the Physiological Laboratory 
of the University of Edinburgh, one can clearly see the intracellular 
nutritive canaliculi, the existence of which has been inferred 
by Professor Browicz (fig. 1). They are everywhere throughout 
the sections filled with the carmine gelatine injection material with 
which the vessels have been injected from the portal vein, and here 
and there is seen what appears to he a direct offset from a blood 
capillary to the intracellular network. The injection within the 
cells is not irregularly diffused nor limited to the exterior layers of 
the cytoplasm, but is confined within sharply defined, somewhat 
varicose intercommunicating canaliculi, many of which are in the 
immediate neighbourhood of the nucleus or nuclei, but never, so 
* Bull . internat. de Vacad. d. Sc. de Cracovie , Juillet 1899, pp. 369, 370. 
