FAMILY MACROPODID^E ; KANGAROOS. 349 



on its fore-paws, as well as on the hinder extremities, whilst it 

 browses on the herbage ; and in this attitude it hops gently 

 along, deriving some assistance from its tail. On the least 

 alarm, however, it raises itself on its hind legs, and bounds 

 away to a distance with great rapidity. The leap is of very 

 great length ; and is accomplished by the muscular action of 

 the tail, almost as much as by that of the limbs (ANIM. PHY- 

 SIOL., 661). Sometimes the old male of the Great Kangaroo, 



FIG. 173. SKELETON OF KANGAROO. 



when excited, stands on tiptoe, and on his tail, the three extre- 

 mities forming a tripod ; and is then of prodigious height. The 

 great length of the hind foot is chiefly given by the elongation 

 of its metatarsal bones ; it possesses four toes, of which the two 

 inner ones are very small, and compacted together so as to 

 appear like one ; the third or middle toe is large and powerful, 

 and armed with a strong hoof-like nail ; the fourth or external 

 toe is smaller than the middle one, but is larger than the two 

 inner ones together, and it also has a large hoof-like nail. These 

 defences make the foot a very powerful weapon ; a single blow 

 from it being often sufficient to kill a dog. The under side of 

 the foot has a callous sole along its whole length. The fore- 

 paws have five toes armed with sharp claws ; they enjoy consider- 

 able freedom of motion, the clavicles being well developed ; and 

 they are used by the animal for a great variety of purposes. 

 They even aid the Kangaroo in its defence ; for it will sometimes 



