TUMOURS AND CANCERS. 247 



dular organs, and used this as an explanation of the 

 inordinate number of teats found within the pouch of 

 some opossums. It is a remarkable fact that one of the 

 most typical specimens of cancer that has come under 

 my notice in a wild animal occurred in a short-headed 



FIG. 123. The posterior half of a short-headed Phalanger. The pouch is 

 occupied by a cancer. (Nat. size.) 



phalanger (Belideus breviceps) (fig. 123). In this case the 

 pouch was occupied by a tumour as big as the kernel 

 of a filbert, and when we remember that the parts of the 

 phalanger are represented of natural size in the drawing, 

 the tumour was relatively large. In order to appreciate 



