THE NATURAL HISTORY OF THE KANGAROO. 
379 
It is not improbable, however, that kangaroos were seen by 
the earlier explorers of the western coast of Australia ; and it 
may be that it is one of these animals which was referred to by 
Dampier, when he tells us that on August 12, 1699, “two or 
three of my seamen saw creatures not unlike wolves, but so 
lean that they looked like mere skeletons.” 
Having now learned something of the structure, habits, and 
history of the kangaroo, we may proceed to consider its zoolo- 
gical, geographical, and geological relations, in order to arrive 
at the best answer we may to our initial question, “What is a 
kangaroo ? ” 
First, as to its zoological relations : and here it is necessary 
to recall to mind certain leading facts of zoological classifica- 
tion, in order that we may be better able to see with what 
creatures the kangaroo is, in various degrees, allied. 
The whole animal population of the globe is spoken of under 
the fanciful term, the “ animal kingdom,” in contrast with the 
world of plants, or “ vegetable kingdom.” 
The animal kingdom is divided into certain great groups, 
each of which is called a sub-kingdom ; and one, the highest of 
these sub-kingdoms (that to which we ourselves belong), bears 
the name vertebrata , and it includes all beasts, birds, reptiles, 
and fishes ; and the name refers to the series of bone called 
vertebrce , of which the back-bone or spinal column (and all ver- 
tebrata have a spinal column) is generally made up. 
Each sub-kingdom is made up of subordinate groups, termed 
classes ; and thus the vertebrate sub-kingdom is made up of the 
class of beasts or Mammalia (so called because they suckle 
their young), the class of birds, and other classes. 
Each class is made up of subordinate groups, termed orders ; 
each order is further subdivided into families ; each family is 
made up of genera ; while every genus comprises one, few, or 
many species. 
In considering the zoological relations of the kangaroo, we 
have then to consider the relations borne by its genera to the 
other genera of its family, the relations borne by its family to 
the other families of its order, and finally the relations borne 
by its order to the other orders of its class (the Mammalia ) — 
that class which includes within it all other beasts whatever, 
and also man. 
In the first place, it may be observed, there are many species 
of kangaroos, arranged in some four genera ; but the true kan- 
garoos form a genus Macropus, which is very nearly allied to 
the three other genera. (2) Dor cop sis, with a very large first 
back tooth. (3) The tree kangaroos ( Dendrolagus ), which 
frequent the more horizontal branches of trees, have the fore 
limbs but little shorter than the hind limbs, and inhabit New 
