THE POUCHED MAMMALS. 237 



There are also a few species still living in America, but at 

 the present day not a single marsupial animal lives on the 

 continent of Asia, Africa, or Europe. 



The name of pouched animals is given to the class on 

 accoxmt of the purse-shaped pouch (marsupium) existing 

 in most instances on the abdominal side of the female 

 animals, in which the mother carries about her young 

 for a considerable time after their birth. This pouch is 

 supported by two characteristic marsupial bones, also 

 existing in Cloacal aninjals, but jiot in Placental animals. 

 The yoimg Marsupial animal is bom in a much more 

 impeifect form than the young Placental animal, and only 

 attains the same degree of developnaent which the latter 

 possesses directly at its birth, after it has developed in the 

 pouch for some time. In the case of the giant kangaroo, 

 which attains the height of a man, the newly born young 

 one, which has been carried in the maternal womb not 

 much longer than five weeks, is not more than an inch 

 in leng-th, and only attains its essential development 

 subsequently, in the pouch of the mother, where it remains 

 about nine months attached to the nipple of the mammary 

 gland. 



The different divisions generally distinguished as families 

 in the sub-class of Marsupial animals, deserve in reality 

 the rank of independent orders, for they difier from one 

 another in manifold differentiations of the jaw and limbs, in 

 much the same manner, although not so sharply, as the 

 various orders of Placental animals. In part they perfectly 

 agree with the latter. It is evident that adaptation to 

 similar conditions of Kfe has effected entirely coincident or 

 analogous transformations of the original fundamental form 



