THE SPLEEN IN MARSUPIALS. 



somewhat in shape the human type, forming a triangular 

 body 7 cm. long and 4 cm. across, with two small projec- 

 tions, one directed towards the oesophagus and the other 

 representing the left dorsal process. The right process 

 is much more mobile than the body, and while the width 

 of great omentum between the left extremity and great 

 curve of stomach equals 2.5 cm., at the right extremity 

 this equals 9 to 10 cm. In some specimens the body is not 

 relatively so large, and in place of the projections two 

 processes are seen, separated by a well-defined interval or 

 gap. 



M aero pod id ae (Kangaroos and Wallabies,) 



The spleen consists of three portions : (1) left, largest 

 portion or body; (2) narrow elongate or right process; 

 (3) wider, though shorter, dorsal left process. 



The body varies from 11 to 15 cm. in length, with 

 a maximum width of 4.5 cm. The short left process is 6 

 cm., with a maximum width of 3 cm. ; and the right pro- 

 cess 9.5 cm. long, and maximum width 3.75 cm. 



Frequently the width of this process may only equal 

 1 em., with a narrow attachment to the body — the connec- 



7 *s 



tion being fibrous, with a sprinkling of splenic tissue. 

 Such a process is one apparently undergoing a retrogres- 

 sive evolution, and is found both in the Wallaby and 

 Kangaroo. In the Tasmanian Wallaby I found the 

 anterior process to be not only narrower but shorter than 

 the left process. The great stomach in Macropus is a 

 V-shaped organ with a large left and a smaller right 

 limb, and the well-defined Spigelian lobe of the liver de- 

 pending between the two. The body and elongated right 

 process are suspended on the great omentum (lesser sac), 

 being related to the greater curvature of the left limb 

 as far to the right as the bend in the stomach. The pro- 



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