364 MARSUPIALS. 



unknown to science, and which will supply many of the links which are needed to complete 

 the system of nature. 



There is hardly any practical writer on zoology who does not lament the very incomplete 

 state of our knowledge on this subject ; and those who have thrown themselves most zealously 

 into the work, and have achieved the greatest success, have been the most ready to acknowl- 

 edge the enormous gap that has yet to be filled, and to urge others to prosecute their researches 

 in regions which have as yet been untraversed by the foot of civilize*! man, and which are the 

 most likely to be the dwelling-places of creatures on which, as yet, an educated white man has 

 never set his eye. Several genera are known to be extinct, and there are interesting accounts 

 of fossil discoveries in Aiistralia, which bring to light the remains of gigantic animals of the 

 same kind as those which now inhabit that country. 



So distinct are many of the animals of Australia from those of the Old World, that more 

 than one zoologist has confessed that they seem to be the result of another and a later creation 

 than that by which the animals of the northern hemisphere received their being. 



The peculiarity which gives the greatest interest to this group of animals, is that wonder- 

 ful modification of the nutritient organs, which has gained for them the title of MAESUPIALIA, 

 or pouched animals a name which is derived from the Latin word marsupium, which signifies 

 a purse or pouch. This singular structure is only found in the female Marsupials, and in 

 them is variously developed according to the character of the animal and the mode of life for 

 which it is intended. 



The more minute details concerning the marsupium, or pouch, will be found in the course 

 of the work in connection with the particular species to which it belongs, but the general idea 

 of that structure is much as follows : 



The lower part of the abdomen is furnished with a tolerably large poiicli, in the interior 

 of which the mammae, or teats, are placed. When the young, even of so large an animal as 

 the kangaroo, make their appearance in the world, they are exceedingly minute the young 

 kangaroo being only an inch in length and entirely unable to endure the rough treatment which 

 they would meet with were they to be nurtured according to the manner in which the young 

 of all other animals are nourished. Accordingly, as soon as they are born, they are transferred 

 by the mother into the pouch, when they instinctively attach themselves to the teats, and 

 there hang until they have attained considerable dimensions. By degrees, as they grow older 

 and stronger, they loosen their hold, and put their little heads out of the living cradle, in order 

 to survey the world at leisure. In a few weeks more they gain sufficient strength to leave the 

 pouch entirely, and to frisk about under the guardianship of their mother, who, however, is 

 always ready to receive them again into their cradle if there is any rumor of danger ; and if 

 any necessity for flight should present itself, flies from the dangerous locality, carrying her 

 young with her. 



In some of the Marsupials the pouch is hardly deserving of the name, being modified into 

 two folds of skin, so that the mother is obliged to find other means of carrying her young from 

 place to place. In the structure of the animal there is an admirable provision for sustaining 

 the pouch and its contents, and preventing it from exerting too painful a "drag" upon the 

 skin and walls of the abdomen. Two supplementary bones, called, from their position in the 

 pouch, the marsupial bones, issue from the pelvis, and are directed forward almost parallel to 

 the spine. On account, however, of the method in which certain muscles wind round the 

 marsupial bones, and taking into consideration the fact that these structures are found in both 

 sexes, Mr. Owen considers that their chief aim is not so much in affording support to the 

 pouch as in compressing the numerous glands, so as to aid the feeble young in gaining 

 nourishment. 



We will now leave their general consideration, and proceed to examine some of the prin- 

 cipal species which are contained in this wonderful group of animals. 



AT the head of the MacropidsB are placed a small but interesting band of marsupial ani- 

 mals, which are called Phalangistines, on account of the curious manner in which two of the 

 toes belonging to the hinder feet are joined together as far as the " phalanges." The feet are all 



