174 DE. J. MTmiB ON THE FOEM AJSTD STEFCTUEB OF THE MANATEE, 



margin of each; and the left possesses a small subtriangular lobule at its posterior 

 spinal corner. The third smaller anterior and semidivided lobe, transversely bitrian- 

 gular or oo-shaped, Steller's anvil-formed and Owen's quadrate-figured portion, may 

 either be regarded as the homologue of the so-called cystic lobe of some mammals, 

 or as representing additional upper or anterior lobules of the right and left lobes, 

 bridged together by a diminutive lobus quadratus. This last, as in the human subject, 

 is that portion bounded dorsally by the transverse fissure, laterally by the gall-bladder 

 on the one side, and the round ligament and short longitudinal fissure on the other. 

 There is a compressed boot-shaped diminutive lobule immediately to the right of the 

 inferior vena cava, and a second rather elongate, but terminally flattened, lobule 

 attached to the left wall of the same vein. Both of these small lobules spring from 

 the root of the main right lobe, and respectively appear to be homologous with the 

 caudate and Spigelian lobes. 



Owen remarks that the small Spigelian lobulus in the Dugong is continued from the 

 root of the left lobe. This origin, however, according to my observations in those 

 mammals where the liver is deeply cleft, would not precisely correspond with the 

 Spigelian lobule, which arises from the right moiety, and is separated from the left lobe 

 by the ductus venosus. Notwithstanding, it does not militate against the Professor's 

 clear definition that " the homologue of the ' Spigelian lobule ' is shown by its relation 

 io the lesser curvature of the stomach " '. 



All the hepatic fissures are shallow. The most marked ones, the longitudinal and 

 that of the ductus venosus, being filled up by strong fibrous tissue, covering the vessels 

 therein. As to the ligaments, the susjiensorium Jiejjatis is moderately broad, and firmly 

 fixes the organ to the pericardium and the diaphragm. The round ligament, as usual, 

 forms the anterior or ventral one positionally. In the young male it was a narrow 

 cord, nearly impervious, 1 inch from the liver. The two lateral ligaments diverge 

 from the vena cava, and traverse lengthwise the right and left lobe about an inch 

 outside their vertebral margins. 



The pyriform but forwardly projecting gall-bladder lies superficially on the ventral 

 aspect of the small antei'ior right lobule. When distended it is 2^ inches long and 

 1 inch in diameter at the fundus. The cystic duct, of considerable calibre, winds in an 

 S-shaped manner, and at about three quarters of an inch distance from the neck of the 

 gall-bladder receives singly the united hepatic duct on its left wall, as Daubenton and 

 Vrolik have recorded. In the Dugong the cervix of the gaU-bladder is said to be 

 obliquely pierced by two hepato-cystic ducts, entering, as the ureters do, into the 

 urinary bladder. The ductus communis choledochus in the male Manatee was as thick 

 as the barrel of a goose-quill, and penetrates the intestine about three inches from the 

 pylorus. 



1 ' The Anatomy of Vertebrates ' (1868), vol. iii. p. 483. See also Owen " On the Anatomy of the Cheetah," 

 Trans. Zool. Soc. vol. i. p. 131. 



