FLYING-SQUIRRELS— GROUND-SQUIRRELS 191 



about loose in a country place. In any case, if confined* they should not be put 

 into the abominable wheel-cages so often used ; a Squirrel needs a very large cage, 

 at least two feet every way, with' a sleeping-box. Squirrels do not hibernate in 

 winter, though they may keep at home in their nests in bad weather ; but in autumn 

 they make some attempt to provide against winter emergencies by burying nuts and 

 acorns in the ground ; many of these are not consumed, and so Squirrels uncon- 

 sciously aid in the extension of the trees which bear their food. 



It ought to be mentioned that the American Grey Squirrel {Sciurus cinereus), 

 which is larger than our animal and without ear-tufts, has been introduced into 

 Bedfordshire, and seems quite established there. A few may also be seen in the 

 Zoological Gardens and other parts of Regent's Park ; the species is a very familiar 

 one in American parks, where it has domesticated itself. 



FLYING-SQUIRRELS 



There is a group of Squirrels which, though agreeing in general habits with ordi- 

 nary Squirrels, differ in possessing a parachute-like expansion of the skin along the 

 sides, like that found on the Cobego, but not so well developed, there being little, or 

 not any, of this before or behind the legs. The use of this structure is, of course, 

 the same as in the Cobego, to enable the animal to take long sailing jumps from 

 one tree to another. Flying-Squirrels differ from typical Squirrels in being 

 nocturnal ; the larger kinds {Pteromys), some of which are the biggest Squirrels 

 known, are purely Asiatic, and these have the parachute-skin best developed. The' 

 smaller ones {Sciuropterus) are not only found in Asia, but there is one in Europe,- 

 and one in America (Sciuropterus volucella), a very beautiful little grey animal, not 

 so big as a Rat, which is sometimes imported here as a pet, and has bred 

 in captivity. This is rather remarkable, for, as a rule, Squirrels very seldom 

 reproduce in that condition, though they are easy enough to keep. 



GROUND-SQUIRRELS 



One usually associates Squirrels with trees, but a considerable number of species 

 live on the ground, these being the Ground-Squirrels {Tamias), of which the pretty 

 little American Chipmunk, something like the Indian Striped Squirrel, but smaller, 

 is an example, and the animals of the genus Spermophilus, exemplified by the 

 Souslik of the Old World and the so-called Striped Gophers of the New. There 

 are also Ground-Squirrels (Xerus) in Africa. These terrestrial Squirrels live in 

 holes, and resemble Rats in their habits. Some of them, with fair-sized ears and 



