328 THE ADRENAL, GENERAL MOTOR, AND VAGAL SYSTEMS. 



tissue. This is the hepatic artery, which supplies blood for the 

 nutrition of the connective tissue of the organ, the vessel-walls, 

 etc. It ultimately terminates in the small portal veins, and 

 perhaps partly in the capillaries in the periphery of the lob- 

 ules." 



There exists some uncertainty as to the manner in which 

 the subdivisions of the hepatic artery are related to the other 

 perilobular and intralobular vessels. Pick and Howden 12 refer 

 to its terminal distribution as follows: "Finally, it gives off 

 interlobular branches, which form a plexus on the outer side 

 of each lobule, to supply its wall and the accompanying bile- 

 ducts. From this lobular branches enter the lobule and end in 

 the capillary net-work between the cells. Some anatomists, 

 however, doubt whether it transmits any blood directly to the 

 capillary net-work/' Harrison Allen 13 says: "Each lobule is 

 a miniature liver having at its periphery between the lobules 

 branches of the portal vein and hepatic artery (interlobular 

 branches) which freely intercommunicate and form through the 

 lobule, between its periphery and center, a capillary net-work. 

 Directly at the center the venules of this net-work (intra- 

 lobular vessels) converge to form radicles of the hepatic vein." 

 Labadie-Lagrave 14 states that, "as regards the divisions (of the 

 hepatic artery) destined for the lobules, they penetrate con- 

 jointly with interlobular veins, but without communicating with 

 them, in the interior of the lobule, in the form of capillaries 

 distributed to the central vein" In the presence of these di- 

 vergent views, which but exemplify those of other authors, 

 our only choice lies in the selection of the one region which 

 all authors seem to consider as reached by the artery: i.e., the 

 periphery of the lobule. But, as all concede, also, that the 

 arterial capillaries penetrate in one way or another to the 

 intralobular supply, we will adopt though we believe that 

 Harrison Allen's definition is the true one the more con- 

 servative distribution indicated in the annexed engraving by 

 Piersol, who, in accord with many histologists, describes the 



"Pick and Howden: "Gray's Anatomy"; edition, 1901. 

 18 Harrison Allen: "Human Anatomy," 1884. 

 "Labadie-Lagrave: "Traite" des Maladies du Foie," 1892. 



