PLATYPUS AND ECHIDNA. 



liver between it and the oblique fissure which is the 

 spigelian lobe. Passing from the ventral extremity of the 

 small fissure to the vena cava, so that it runs between the 

 right lateral and spigelian lobes, is a membrane 2 cm. 

 long attached above to the diaphragm. The fissure and 

 membrane correspond to the hepatic relationship of the 

 inf. vena cava, and the spigelian lobe is seen to be part 

 of the right lateral lobe. The inf. v. cava, is not seen on 

 this aspect. It lies behind the junction of the right 

 lateral and spigelian lobes and the length from entrance 

 to exit is 3.5 cm. Its exit corresponds to practically the 

 middle of the coronal fissure. Passing backwards from 

 about the middle of the ventral margin of the cystic lobe 

 we may see a fissure 2 cm. long through which and 

 especially if distended the gall bladder projects. More 

 often a gap is seen on the ventral edge enabling the gull 

 bladder to be seen on this aspect. It is 1 cm. long and .75 

 cm. wide, and from the gap we rind passing dorsally two 

 fissures — one mesial corresponding to the suspensory 

 ligament and the other oblique and dextral in which the 

 gall bladder projects. Between these two fissures we see 

 on this aspect an early indication of the lobus quadratus 

 so well defined in the human liver. It is about .75 cm. 

 laterally. 



In the middle of the mesial lobe we see the longitudi- 

 nal or suspensory ligament — a triangular fold attached 

 above to the muscular and tendinous portion of the dia- 

 phragm. It passes forward from the coronal fissure to the 

 gall bladder cleft or fissure and measures 3 cm. on its ven- 

 tral aspect. It represents part of the original ventral 

 mesogaster. By its means and the cleft the mesial lobe is 

 divided into right and left portions. In addition to the 

 fold between the right lateral and spigelian lobes two fine 

 peritoneal folds are noted from the dorsal margins of 

 the right and left cystic lobes to the diaphragm. At the 



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