THE YJ.POCK. IL * 



It is very curious that the young of these pouchless Opossums should resemble those of the whole 

 order in being comparatively little advanced in their development at the time of their birth. The 

 young are at first strongly attached to the teats of the mother, and when they are sufficiently strong 

 and grown to leave them, occasionally she takes them off from the nipples and places them on her 

 back Here they cling on with their tails to hers. Hence the name of back-bearing, or Dorsigera, 

 which is given to this kind. 



It was at first supposed that this method of carrying the young was restricted to this species, but 

 subsequent experience has shown that several kinds do the same thing. 



Two or three other species of Opossum are interesting from their small size and habits. Thus the 

 Murina Opossum (Didelphys murina), with a very long tail, inhabits Guiana, Brazil, Peru, and Mexico. 

 The body is about five inches in length, and the tail is either slightly longer or about the same. Yet this 

 little thing attacks birds and insects ; it burrows in the ground, and climbs trees to get its insect food. 



The Elegant Opossxim (Dldelphys elegans), of Chili, is still smaller than the last, and frequents 

 the thickets growing on the rocky hills near Valparaiso. They are numerous, or were so when 

 Mr. Darwin observed them, and are easily caught in traps baited with cheese or meat. The tail 

 appeared to be rarely, if at all, used as a prehensile organ ; yet they could run up trees with some 

 degree of facility. It is an interesting fact that some of the smallest Opossums prey upon Lizards and 

 Snakes as large, and even heavier, than themselves. 



The last section of the Opossums contains the Water Opossum, 



THE YAPOCK.* 



This animal has a perfect pouch, and has large hind feet, the toes of which are united by a web. 

 The fore feet are moderate-sized, and the pisiform bone is unusually long. Its habits are aquatic. 



* Chironectes variegatus. 



