320 PROFESSOR FRANK J. COLE 



the occurrence of the extra anterior hepatic duct mentioned above. If the gall bladder 

 is split open, and its internal surface carefully examined, there is no difficulty in 

 finding the three perfectly distinct apertures as I have described them. 



2. General Anatomy of the Liver. 



(A.) First, as regards the blood-vessels and hepatic ducts. The sub -intestinal vein, 

 on reaching the posterior extremity of the posterior lobe of the liver, behaved in one 

 case as follows : it split into two large vessels — one passing on to the ventral convex 

 surface of the lobe, and the other on to the dorsal concave surface. The latter itself 

 split into two almost equally sized vessels, and both, after repeated branching, were 

 finally dissolved among the liver tubules. This proves that the sub-intestinal vein 

 acts not only as a collector but as a distributor, i.e. that it brings blood to the liver 

 just as the portal vein does. 



On the other hand, the vessel on the convex ventral surface, which represents the 

 main trunk of the sub-intestinal vein, remained fairly constant in size in spite of 

 frequent interchange of vessels with the liver. Large veins were undoubtedly received, 

 showing that the sub-intestinal collects blood returning from the liver, and is therefore 

 the 'posterior hepatic vein. Its course is always more or less superficial. 



No factors of the hepatic duct are associated with the sub- intestinal vein or its 

 constituents. 



Anteriorly the sub-intestinal comes more to the surface of the lobe, and is plainly 

 visible in a surface view. It leaves the posterior lobe at its extreme anterior point as 

 its sole or principal hepatic vein and opens into the sinus venosus. There may, however, 

 in addition, be another efferent vessel associated with the posterior lobe, opening 

 separately into the sinus venosus and corresponding to the similar vessel [anterior 

 hepatic vein) draining the anterior lobe of the liver. It may be called the accessory 

 posterior hepatic vein, and, like the sub-intestinal, it receives blood from the irregular 

 spaces everywhere present between the liver tubules, and courses along the dorsal 

 surface of the lobe. I thought at first that this vessel might be the direct continuation 

 of one of the dorsal branches of the sub-intestinal described above, just as the sub- 

 intestinal itself is continued forwards as the principal hepatic vein of the posterior lobe, 

 but the specimens I investigated with respect to this point gave no support to such 

 a supposition. The accessory posterior hepatic vein, therefore, is a true hepatic vein, 

 and is actually constituted within the substance of the posterior lobe of the hver. 



From behind forwards the above vessels open into the sinus venosus in the following 

 order : (1) accessory posterior hepatic vein ; (2 and 3) posterior hepatic or sub-intestinal 

 vein and anterior hepatic vein almost simultaneously. In front of this region the 

 sinus venosus in my large series of sections received seven independent smallish 

 accessory anterior hepatic veins from the anterior lobe of the liver, which extended 

 forwards for some little distance in front of the place where the main anterior hepatic 

 vein left it. 



