10 PROFESSOR DAVID HEPBURN ON 



sinus on the dorsal aspect of the hilum. The right lobe presented the same mesial and 

 lateral portions which were noted on the diaphragmatic aspect. The mesial portion 

 was divided into dorsal and ventral parts by the hilum. To the ventral portion the 

 gall-bladder was attached, and this part of the right lobe was connected to the left lobe 

 by a puns hepaticae. The dorsal portion was to a large extent concealed by the large 

 hepatic sinus. The lateral part of the right lobe was also divided into dorsal and 

 ventral segments by the extension of the hilum across its visceral aspect. 



A tailed lobe extending from the dorsal segment of the mesial portion of the right 

 lobe passed backwards OD the ventral surface of the inferior vena cava, which was thus 

 embedded in the liver substance. This tailed lobe expanded so as to conceal a consider- 

 able length of the inferior vena cava, and into this hidden part of the cava there opened 

 directly the hepatic veins from this particular lobe, as also the hepatic veins from the 

 lateral part of the right lobe. 



The inferior vena cava itself opened into the large hepatic sinus situated close to the 

 diaphragm and extending right and left of the suspensory ligament. This sinus 

 received the hepatic veins from the right and left lobes of the liver, with the exception 

 of those veins already mentioned as opening directly into the inferior vena cava. The 

 interior of this sinus was imperfectly divided into right and left parts by a crescentic 

 partition which was situated to the right side of the line of attachment of the suspensory 

 ligament, so that the part of the sinus to the left side of the crescentic fold was the 

 larger. The inferior vena cava opened into the hepatic sinus on the right side of the 

 imperfect partition, while on its left side it received the mouth of the ductus venosus. 



The hepatic sinus narrowed for the purpose of passing through the diaphragm in 

 order to enter the right auricle of the heart, but the general size of its lumen was so 

 much greater than that of the inferior vena cava that it is more accurate to say that 

 the inferior vena cava opened into the sinus and the sinus joined the auricle. 



The conditions presented by the hepatic veins afford some interesting light upon 

 the question of their development. Clearly the large hepatic sinus has resulted from 

 the fusion of the two embryonic vense revehentes, although, from the position of the 

 imperfect crescentic partition, it is evident that the left vena revehens was the larger of 

 the two and therefore received the smaller or right vena revehens. This arrangement 

 would therefore appear to provide a variation upon the current statement that " the 

 left vena revehens loses its connexion with the sinus venosus and opens into the right 

 vena revehens" (Cunningham's Text-Hook of Anatomy, 2nd ed., p. 935). Again, the 

 ductus venosus is described as passing directly " from the left vena advehens to the right 

 hepatic vein" (ride ibid.), whereas, in the liver under consideration, the mouth of the 

 ductus venosus opens to the left side of the crescentic fold, which appears to represent 

 the remains of a fusion between the right and left hepatic veins. Further, to quote 

 again from the same authority, " The upper part of the inferior vena cava is developed 

 as an outgrowth from the common trunk formed by the fusion of the ductus venosus 

 with the right hepatic vein." From the present dissection the inferior vena cava would 



(UOY. SOC. ED1N. TRANS., VOL. XLVII., 62.) 



