i8o 



THE FOOD OF ANIMALS 



specialized work against one another like scissors, and are kept 

 sharp by mutual wear. A further adaptation to plant -food is 

 found in the complex nature of the stomach, which recalls what 

 has been described for other cases. 



POUCHED MAMMALS (MARSUPIALS) 



Marsupials, as represented by the forms living in the Aus- 

 tralian region, to which the large majority of existing species 

 are confined, have already been instanced as an interesting order 



Fig. 426. The Koala (Phascolarctos cinereus] 



which, in the absence of competing mammals of higher structure, 

 have become specialized in various directions so as to fit them 

 for food of all kinds, some species playing the part of carnivores, 

 others of insectivores, and so on. A similar wide range of 

 adaptations is found among the plant-eating forms of this order, 

 and these may conveniently be described as making up three 

 sections, including respectively fruit-eating, herbivorous, and root- 

 eating marsupials. 



FRUIT-EATING MARSUPIALS include the Phalangers (Phalangis- 

 tidcz), climbing forms known as " opossums" to the colonists, 



