KANGAROOS AND WALLABIES. 



is no definite caudate lobe in Macropus. We may see a 

 projection on the inner part of the right lat. lobe corre- 

 sponding to it, but the important point is that the vena 

 cava has come to the ventral surface. Why the fissure? 

 Is this acquired for more elasticity in relation to the 

 pyloric portion of the stomach — remembering the rela- 

 tively enormous size of the Maeropod's stomach — or are 

 we dealing with a primitive right lobe, i.e., the upper part 

 to be regarded as right lobe, since it is separated from the 

 cystic by a fissure, and the lower to be regarded as cau- 

 date, hollowed below for the kidney. If we do regard the 

 lower portion as caudate the inner portion has disap- 

 peared, and the two portions are now practically one. 

 The liver of the Macropod then is important in reference 

 to the evolution of the caudate lobe, suggesting atrophy 

 internally and fusion — unification — externally. 



Inf. V. Cava.'- -This is seen to lie obliquely on the 

 inner or left margin of the right lateral lobe, and passing 

 ventral to it between the spigelian on the left, and the two 

 parts of the right lateral on the right, are the portal 

 vein, artery, and common bile duct — the portal vein and 

 inf. v. cava being in close relationship. The vena cava 

 completely separates the spigelian and right lateral lobes 

 -no caudate lobe is present — and the spigelian lobe is 

 seen to be really connected with the left lat. lobe, and not 

 with the right lateral. 



Lesser Omentum. — A continuity is established with 

 the suspensory membrane at the inf. v. cava on the dia- 

 phragmatic aspect. The membrane, which is really the 

 old ventral mesentery, passes behind the projection on the 

 dorso-internal aspect of the left lat. lobe to the visceral 

 surface. The lesser omentum is traced along the internal 

 or right margin of the left lat. lobe to the portal interval, 

 being seen immediately above the lobus spigelii. 

 Dl 34- 



