MARSUPIALIA. 107 
of the Carnaria as a fourth family of that great order, that it appears to 
us they should form a separate and distinct one, particularly as we observe 
in them a kind of representation of three very different 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 mamme 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 mamme 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 
