45 
in this pouch, where it attaches itself to a nipple and remains 
for some weeks until it has attained a weight of several 
pounds, when it gradually begins to come forth. It does not 
permanently leave the bag until it has grown so large as to 
be of an inconvenient size for the mother to carry about. 
The order is a large one, and outside of the Australian region 
contains only the opossums of America. It presents a striking 
variety of habits and adaptations of form among its members ; 
many of the other mammalian orders being represented by 
marsupial forms, which agree, more or less perfectly, with 
them in habits. 
The kangaroos fill a number of places in the economy of 
their native regions—there being brush kangaroos, rock kan¬ 
garoos, and tree kangaroos, all of which are equally at home 
in the surroundings indicated by their respective names. 
The wallabys are a sub-group of kangaroos, differing slightly 
in structure. 
The Rufous Rat Kangaroo (sEflrymnus rufescens) and 
Gaimard’s Rat Kangaroo (Bettongia gaimardi') are small 
species from New South Wales. 
All of the kangaroos are strictly herbivorous; most of them 
are hardy, breed readily, and might be acclimated in parks in 
the warmer temperate parts of the United States, with little 
difficulty. 
Marsupials are probably near to the primitive ancestral 
mammals, fossil teeth having been found in the Jurassic forma¬ 
tion, near Oxford, England, and also in the United States, 
the possessors of which without doubt belonged to this 
group, and in modern systems of classification they stand 
next to the lowest mammals; the Monotremata , consisting of 
two forms peculiar to Australia, being at the bottom. These 
Strange animals, although of the mammalian class, possess 
Certain structures of reptilian type, which affinity is even 
more strangely shown by the now established fact that 
they, alone among mammals, lay eggs which are hatched 
outside of the body of the parent, as in birds and many 
reptiles. 
The society was fortunate enough in 1887 to secure a 
specimen of the Echidna, sometimes called the Spiny Ant- 
eater (.Echidna hystrix ), which lived for some months, an 
object of great interest to all classes of visitors. A second 
example has lived, at the present time, nearly a year in the 
Small Mammal House. 
