OBSERVATIONS. 



divisions, the right and left cystic Lobes; and in the Wom- 

 bat, Koala, Phalanger, and Bandicoot, a definite separa- 

 tion of the left division into two portions by means of a 

 fissure, the mesial or cystic fissure has taken place, so 

 that three portions of the mesial lobe are recognized, viz., 

 right mesial, intermediate mesial, and left mesial. The 

 suspensory ligament is noted in relation with the mesial 

 fissure, between the intermediate and the left mesial 

 lobes, and not with the left lateral fissure, between the left 

 mesial and the left lateral lobes. The conveyance of 

 maternal blood to the liver, along the suspensory liga- 

 ment, would be a factor favouring the retention of the 

 mesial fissure, as compared with the left lateral fissure. 

 The human longitudinal fissure corresponds to the mesial 

 or cystic fissure, as is well shown in a study of Gorilla 

 and Wombat, and the intermediate mesial lobe, i.e., 

 between the gall bladder and the mesial fissure, is 

 represented in the human liver by the lobus qnadratus. 

 In the Wombat, in which animal great diversity of liver 

 shape is met with, from the primitive multilobed type to 

 one scarcely distinguishable from the human, irregulari- 

 ties can be studied in connection with this lobe, giving us 

 an indication of its instability. It would further 

 appear that cases of atrophy of the human lobus 

 qnadratus often met with represent the trend of Nature's 

 evolution towards further unification and simplification 

 of the organ, a fact to be remembered in cases of so-called 

 "displacements of the gall bladder.'' This is the experi- 

 mental region of the liver, and there is no reason why 

 the gall bladder fissure in the human liver should not 

 serve for the convevance of the maternal blood to the 

 portal fissure and vena cava, especially when we consider 

 the proximity of portal vein and bile duct to the inferior 

 vena cava in Kangaroo. In William Flower's classifica- 

 tion of the lobes of the liver, followed generally by bio- 



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