THE SPLEEN IN MARSUPIALS. 



terior boundary obliquely down and forward from within 

 1 cm. of the superior extremity to within 1 cm. of the tip 

 of the right ventral extremity below. The lieno-meso- 

 colic fold — which supports the left pancreas and the chief 

 vessels — is attached on this aspect of the left process, and 

 may or may not extend to the left angle or tip. Below it 

 is attached to the ventrum of the caudal pole of the left 

 kidney, so that it is lieno-renal. The left pancreas — ■ 

 unlike the human — can be raised from the front of the 

 kidney. By means of this fold and the anterior part of 

 the gastro-splenic omentum the lower or colic surface is 

 defined. In addition, certain ridges are noticed on this 

 aspect of the spleen. Along the attachments of the lieno- 

 mesocolic and anterior parts of the gastro-splenic mem- 

 branes is a blunt ridge, and following the curve of the 

 upper part of the gastro-splenic membrane a slight 

 ridge may be noticed. Dorsal to the upper part 

 of the gastro-splenic membrane is a sharper ridge — 

 renal ridge — the result of renal pressure, and separating 

 off the renal and gastric surfaces. The renal ridge is 

 traced along the left extreinhw, forming a prominence 

 below. 



(1 ) Gastric surface (right or upper) is somewhat tri- 

 angular and concave for the fundus of the stomach. It 

 corresponds to the body and right anterior process. 

 Dorsally is the attachment of the gastro-splenic omentum 

 with some small vessels, and below it is separated from 

 the colic surface by the gastro-splenic membrane in front 

 and the lieno-mesocolic behind. The pancreas, supported 

 on the lieno-mesocolic fold, tends to encroach on the 

 gastric surface between this fold, the renal ridge, and the 

 gastro-splenic omentum. The dorsal limitation of this 

 surface is the ridge behind the gastro-splenic omentum; 

 or where the depression for the kidney is well marked a 

 defined margin separates it from the renal surface. 



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