THE LIVER IN MONOTREMATA. 



PLATYPUS AND ECHIDNA, 



The liver, as in the human foetus, stretches across the 

 upper abdomen, being placed in the epigastric and right 

 and left hypochondriac regions. In the human adult it 

 lies in the epigastric and right hypochondriac regions 

 only. Bv means of the right lobe and the lobus caudatus 

 the liver is prolonged along the right dorsal abdominal 

 wall reaching as low as the 11th rib. 



Diaphragmatic Surface. — - (a) Platypus. — On this 

 aspect of the liver an immediate division into three parts 

 is evident, aTz. mesial or cystic (ventral), right and left 

 lateral (dorsal). 



Dextrallv and distinct from the right lobe we may see 

 a portion of the lobus caudatus. The mesial or cystic 

 lobe is separated from these two latter b} T means of a 

 coronal or transverse lissure and the lateral lobes are 

 separated by an oblique fissure running downwards and 

 to the left. The oblique fissure is not prolonged as far 

 ventrally as the coronal fissure. There is usually 1 cm. 

 of hepatic tissue between the two. If it were so pro- 

 longed it would reach the exit of the inf. v. cava. At 

 the dorsal extremity of the fissure is a gap; here the 

 oesophagus passes to the stomach and in relation also to 

 the gap is the small lesser curve of the latter. Towards 

 the left aspect dorsally of the right lateral lobe a small 

 fissure is seen about 1 cm. long — though more marked in 

 some than in others — and serving to define a portion of 



l B 



