STRUCTURE OF THE LIVER. 



323 



surrounding them and limiting them, and from this cir- 

 cumstance called inter -lobulair veins. From these small 

 vessels a dense capillary network is prolonged into the 

 substance of the lobule, and this network gradually gather- 

 ing itself up, so to speak, into larger vessels, converges 

 finally to a single small vein, occupying the centre of the 

 lobule, and hence called mtra-lobulsiY. This arrangement 

 is well seen in fig. 84, which represents a transverse sec- 

 tion of a lobule. The smaller branches of the portal vein 

 being closely surrounded by the lobules, give off directly 



Fig. 84.* 



mter-lobnlax veins (see fig. 83) ; but here and there, espe- 

 cially where the hepatic artery and duct intervene, branches 

 called vaginal first arise, and breaking up in the sheath are 



* Fig. 84. Cross section of a lobule of the human liver, in which 

 the capillary network between the portal and hepatic veins has been fully 

 injected (from Sappey) . i. Section of the intra-lobula.? vein; 2, its 

 smaller branches collecting blood from the capillary network ; 3, inter- 

 lobular branches of the vena portse with their smaller ramifications passing 

 inwards towards the capillary network in the substance of the lobule. 



