CAPILLARY VESSELS OF THE LIVER. IQJJ 



tered by the inte^lobular (or portal) vein, flows through 

 the capillary network into the intralobular vein, whence, 

 by means of the hepatic veins, it is conducted back again 

 to the heart. Now, in the case of an injected liver, this 

 network is seen to be so close that what interstices there 

 are left seem almost to occupy less room than the ves- 

 sels themselves. We can thus easily imagine how the 

 older anatomists, such as Ruysch, came to be led by 

 their injections to the supposition that nearly everything 

 in the body was made up of vessels, and that the differ^ 

 ent organs were only distinguished by differences in the 

 arrangement of their vessels. But just the opposite to 

 what is observed in an injected preparation does the 

 proportion between vessel and tissue appear to be in an 

 ordinary specimen from a liver. In this the vessels are 

 scarcely perceptible. A similar network is indeed seen, 

 but it is the network formed by the hepatic-cells (Fig. 

 27), which, closely crowded, one against the other, fill 

 up all the inter-spaces of the vessels. It is plain, there- 

 fore, that the capillary and hepatic-cell networks are 

 interwoven in the most intricate manner, so that cells 

 belonging to the parenchyma of the liver everywhere lie in 

 almost immediate contact with the walls of the vessels, 

 there being at most a fine layer between the cells and 

 the walls, concerning which it is still a matter of dispute 

 amongst histologists whether it is to be regarded as a 

 peculiar coat, constituting the finest gall-ducts, or only 

 as a very small quantity of connective tissue accom- 

 panying the vessels. 



In this extremely simple case, a tolerably simple rela- 

 tion may certainly be assumed to exist between the ves- 

 sels and the cells ; it may be conceived that the blood 

 which flows through the vessels may, in proportion to 

 the degree in which they are contracted or dilated, and 

 to its own quantity, exercise a direct influence upon the 



