MARSUPIALIA. 107 



of the Carnaria as a fourth family of tluit great order, that it appears to 

 us they shoukl form a separate and distinct one, particularly as we observe 

 in them a kind of representation of three very diiFerent orders. 



The first of all their peculiarities is the premature production of their 

 young, whose state of development at birth is scarcely comparable to that 

 of an ordinary foetus a few days after conception. Incapable of motion, 

 and hardly exhibiting the germs of limbs and other external organs, these 

 diminutive beings attach themselves to the mammas of the mother, and re- 

 main fixed there until they have acquired a degree of development simi- 

 lar to that in which other animals are born. The skin of the abdomen is 

 almost always so arranged about the mammae as to form a pouch in which 

 these imperfect little animals are preserved as in a second uterus ; and to 

 which, long after they can walk, they always fly for shelter at the approach 

 of danger. Two particular bones attached to the pubis, and interposed 

 between the muscles of the abdomen, support the pouch. These bones 

 are also found in the male, and even in those species in which the fold 

 that forms the pouch is scarcely visible. 



The matrix of the animals of this family does not open by a single ori- 

 fice into the extreme end of the vagina, but communicates with this canal 

 by two lateral tubes resembling handles. The premature birth of the 

 young appears to depend upon this singular organization. The scrotum 

 of the male, contrary to what obtains in other quadrupeds, hangs before 

 the penis, which, when at rest, is directed backwards. 



Another peculiarity of the Marsupialia is, that notwithstanding a general 

 resemblance of the species to each other, so striking that for a long time 

 they were considered as one genus, they differ so much in the teeth, the 

 organs of digestion, and the feet, that if we rigorously adhered to these 

 characters, we should be compelled to separate them into several orders. 

 They carry us, by insensible gradations, from the Carnaria to the Roden- 

 tia, and there are even some animals which have the pelvis furnished with 

 similar bones ; but which, from the want of incisors, or of all kinds of 

 teeth, have been approximated to the Edentata, where, in fact, we shall 

 leave them, under the name of Monotremata. 



In a word, we would say that the Marsupialia form a distinct class, pa- 

 rallel to that of quadrupeds, and divisible into similar orders : so that if 

 we were to arrange these two classes into two columns; the Sarigues, 

 the Dasyuri, and the Perameles would be opposite to the insectivorous 

 Carnaria with long canini, such as the Tenrecs and the Moles ; the Pha- 

 langers and the Potoroos, opposite to the Hedgehogs and Shrews ; the 

 Kanguroo, properly so called, cannot be compared with any thing; but 

 the Phascolomys should be opposite to the Rodentia. Finally, if we 

 were to consider the bones of the pouch only, and regard as Marsupialia 



