MARSUPIALS OR POUCHED ANIMALS 
(Marsupialia) 
THE marsupials stand apart from all the other groups of Ameri- 
can mammals having many peculiarities of structure and habit 
not possessed by any other family. They are in fact the sur- 
vivors of an ancient population which was spread over the earth 
before the superior beasts of to-day made their appearance. At 
about the time that the marsupials had reached the height of 
their development Australia became separated from the mainland 
of Asia, and until the present time these curious primitive ani- 
mals have flourished on this isolated continent, while almost every- 
where else they have been superseded by more highly developed 
and more aggressive beasts. 
Outside of Australia the only known marsupials are the opos- 
sums, which are restricted to South and Middle America, with 
the single exception of the well-known Virginia opossum of our 
Southern and Middle States. 
The variety of Australian marsupials is very great; the largest 
and best-known are the peculiar kangaroos; others resemble in 
general form our smaller carnivora, still others recall the squirrels, 
while the flying phalangers are the counterpart of our flying 
squirrels and there is even a ‘‘marsupial mole!” 
Among the many peculiarities of structure exhibited by these 
animals may be mentioned especially the mode of nourishment 
of the young. Birth takes place when they are extremely small, 
very much earlier than in the higher mammals, and they are 
immediately placed in a peculiar pouch situated on the belly of 
the female where, attached to the nipples, they continue their 
development until able to shift for themselves. Even then they 
return to the pouch for shelter, for a considerable period after 
they can run about. 
The teeth of the marsupials are more primitive than those 
of most of the other mammals and are generally more numerous. 
As might be supposed from the variation in form and size ex- 
hibited by the marsupials their diet is likewise varied, some being 
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