330 THE ADRENAL, GENERAL MOTOR, AND VAGAL SYSTEMS. 



are so joined as to form continuous, though correlated, chan- 

 nels, which radiate from the center of the lobule to its periph- 

 ery, where they join the interlobular bile-channels. 



The intimate structure of the hepatic cell is peculiar. It 

 possesses no limiting membrane; but its peripheral protoplasm 

 is more dense than that of its other parts and the pseudocov- 

 ering so formed serves as the outer wall for numerous cavities 

 or vacuoles which inosculate irregularly throughout its inte- 

 rior. All these vacuoles, however, more or less directly con- 

 verge toward the center, where they meet a protoplasmic mass, 

 which in turn contains one and sometimes two nuclei. The 

 cell, apart from its nucleus, suggests a miniature sponge the 

 cavities of which (secretion vacuoles) become tilled with 



BILIARY CANALICULI. (Mathias Duval.) 

 a, A biliary canaliculus cut transversely, ft, Intercellular capillary. 



glycogen. This substance seems to accumulate in the outer 

 vacuoles, which appear wider in this location than the inner 

 ones, when, by artificial means, the glycogen has been removed. 

 It is perhaps noteworthy that this substance accumulates in 

 the part of the cell nearest the blood-vessels and that the 

 droplets, or "granules," considered as bile are most abundant 

 in the opposite direction: i.e., near the bile-capillaries. These 

 "droplets" accumulate between periods of digestion and dimin- 

 ish during this process. A delicate canaliculus connects this 

 part of the cell with the biliary channel. The vacuoles in the 

 paraplasm, according to Kupffer, "play an important part in 

 the secretion of the cell, and are due to the confluence of 

 minute drops of bile into a large globule. As soon as the 

 vacuole has attained a certain size it tends to empty its con- 



