564 DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 



visions of the portal vein run into the substance of both the third and fourth lobules ; 

 and these, along with the cystic ligament and a moderate amount of hepatic tissue, 

 bridge together this otherwise separate or bifid cystic lobe. Its quadrate segment, our 

 fourth lobule, is about 2 inches broad and 6 inches in extreme length. 



The fifth lobule, counting from the right (v), or right moiety of the left lobe, is large, 

 thick, and almost completely severed from its fellow moiety on the left. From its root 

 to its narrowed free point is 11 inches long; and it varies from 3 to 3 J inches in breadth. 

 Marginally it is fissured, but not deeply, whilst its upper and lower surfaces are 

 throughout very much grooved and ridged longitudinally. The furthest segment to 

 the left, or sixth lobule (vi), is less tapering than the above, and rather smaller, 

 namely 8 by 4^ inches in diameter, though equally thick. Dorsally it is smoother than 

 the fifth lobule, but ventrally is much sculptured like it ; the left compartment of the 

 venous sinus runs well into its substance. 



At the root or middle of this much segmented liver, where the blood-vessels and 

 hepatic ducts split into divisional branches, there are several leaf-like, almost separate, 

 minor lobules. These, together, represent or are homologous with the Spigelian lobe 

 (S), and, numerically considered, count as the seventh hepatic lobule (vn). From them 

 there issues an hepatic duct (no. 4). They lie upon the venous reservoir, slightly to 

 the right of its median constriction, merge into a flat hepatic piece still further on 

 the right, and are themselves partially covered by the hepatic vessels, ducts, and 

 Glisson's capsule. A flat, broad bridge of union (vni), connecting the otherwise separate 

 first, second, third, and seventh lobules, runs outwards from the two latter towards the 

 two former. It is tolerably smooth, and firmly adherent throughout to the vena cava. 

 From its position, and being in some respects an appendage to the lobus Spigelius, as 

 likewise its being situate between the here indefinite transverse fissure, cystic lobe, and 

 divisions to the right of that, it appears to be homologous with the so-called lobus 

 caudatus of Man (C). 



Guided partly by the determination of both the above-mentioned anatomists on 

 diverse Mammalian forms, and partly by a fresh consideration of the corresponding 

 component parts in the human liver — the same organ in the Eared Seal, though greatly 

 segmented, may be said to possess perfectly homologous constituents. That is to say, 

 there is a right, a left, a quadrate, a Spigelian, and a caudate lobe, — each of the two 

 former being cut into segments, the right lobe of human anatomy possessing what 

 Owen has aptly termed a cystic lobe or division. Taking the broad ligament sitspen- 

 sorium hepatis as the line of demarcation, the four divisions to the right of it and above 

 the enlarged venous sinus would together be equivalent to the right lobe of human 

 anatomy. If, however, the parts be read contrariwise, what are here separate portions, 

 have coalesced in those animals wherein the hepatic organ is simpler in conformation. 



b. Hepatic Ducts, Ligaments, and Gall-Madder. — The very separate condition of the 

 numerous lobes of the liver influences the distribution of the hepatic ducts. A branch 



