ZOOLOGICAL GARDENS. 
25 
with one another, and never fell asleep until they had 
cried themselves to sleep, emitting a noise like the whine 
of a very young child, and one generally lay on the 
back of the other, having the ear of its mate in its mouth, 
a habit often observed in young bears. This plaintive 
whining noise was also made by the adult when handled. 
The common Guinea-pig is supposed to be derived from 
the species Cavia ciperea , or the Restless Cavy, a common 
South American rodent, inhabiting the grassy districts at 
the edges of woods. It lives exclusively on vegetable 
substances, and in feeding generally sits up on its hind feet 
and carries the food to its mouth in its paws. It is very 
prolific, and begins to breed at ten months, and generally 
produces a brood of six or eight. This species has often 
suffered martyrdom in the interests of physiological 
research. 
Examples of the genus Arctomys, or the Marmots, 
are generally exhibited in this house, either the 
Himalayan, Alpine, or American species. They belong 
4e—a Family divided into two sections, those without 
buccal pouches or the true marmots, Artomys , and those 
with buccal pouches, SpermopJiilus , smaller animals than the 
former and linking the marmots with the squirrels. They 
are all more or less gregarious, and live in burrows in 
elevated regions. They lay up a store of provisions 
for winter in the chamber in which they live, and in 
which they hibernate during the whole of winter, having 
first shut themselves in from all annoyance by closing 
the door of their house with grass and earth. A number 
of other animals also manifest this remarkable pheno¬ 
menon, and they are known as hibernating animals, and 
chief among them are the Dormouse, most of the 
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