OTHER KANGAROOS 



and the jerboa-rats of Australia, and by the Cape 

 jumping hare (Pedetes caffer) of Africa. To be agile, 

 to traverse arid wastes in the search for water or for 

 herbage, with rapidity, is a sine qua non with all these 

 creatures which have a partiality for plains, and arid 

 ones at that. It is interesting and most .instructive 

 to note how differently in such cases the feet have been 

 constructed for the due carrying of their owners over 

 the ground. In the ungulates either the middle toe 

 or the third and fourth has or have been especially 

 strengthened to meet the demand. In the jerboa 

 the Perissodactyle type of foot has been, we must 

 suppose, quite independently acquired ; for in them 

 digit number three is in the middle and strikes the 

 ground first. In the kangaroos, on the other hand, it 

 is the fourth toe which is predominant ; and it is, as 

 may be easily seen in the living animal, particularly 

 strong and furnished with a huge nail. In bipedal 

 man it is the innermost toe, the first, which mainly 

 bears the weight of the body. There is thus nearly 

 every possible arrangement, which varies according 

 to the group. In the kangaroo the peculiarly tiny 

 third and fourth toes will be noticed to be tied up in a 

 common integument. How thick blood is among the 

 marsupials is shown by the fact that in the phalangers, 

 arboreal creatures quite unlike the kangaroos in general 

 aspect, the same toes are similarly swathed in skin. 

 There are between twenty and thirty kinds of kan- 

 garoos, including the so called wallabies which are not 

 now distinguished from the kangaroos ; the only differ- 

 ence that ever existed was merely one of size. 



THE TREE KANGAROO 



The idea of a kangaroo up a tree suggests a purely 

 metaphorical use of the term to most persons for whom 



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