FAMILY SCIURID^E; DORMOUSE, JERBOA. 253 



gambolling for hours together near the mouths of the burrows ; 

 sentinels having been previously appointed, which indicate to 

 them, from some elevated situation, the approach of danger, and 

 which also reconnoitre when they are about to go on their preda- 

 tory excursions. 



221. The Dormouse, also, has been commonly associated with 

 the Rats ; but in its general habits, the structure of its teeth, 

 and the hairiness of its tail, (which in some species spreads out 

 into a tuft at the end,) it presents a nearer approach to the 

 Squirrels. It has their lively expression and active movements ; 

 and, like them, it builds a kind of nest in the foliage, which 

 is usually, however, situated near the ground. A species which 

 inhabits Southern Europe is known to attack small birds ; but 

 the usual food of that which inhabits this country, consists of 

 haws, young hazel-nuts, and fallen acorns. Of these it lays up 

 a hoard for the winter ; which period is passed by it in a state 

 of almost constant torpidity, though it occasionally awakes to 



take food. The peculiar nature of this state of hibernation, 



which is better displayed in the Dormouse, than in any other 

 warm-blooded animal of our own country, except the Bats, has 

 been elsewhere explained (ANIM. PHYSIOL. 309). The true 

 Squirrels also pass a large part of the winter in sleep ; but they 

 frequently awake to take food, of which they lay up a plentiful 

 store during the autumn. 



222. Another intermediate link between the Squirrels and 

 Rats, but agreeing with the latter rather than with the former, 

 is the Jerboa, which is distinguished by the enormous develop- 

 ment of its hind-legs and tail ; causing it to bear considerable 

 resemblance in form to the Kangaroo ; and enabling it, like that 

 animal, to take prodigious leaps. It resembles the Squirrels in 

 possessing a hairy and tufted tail, and also in the disproportion 

 of its fore and hind-legs ; but in the conformation of its teeth, 

 it is more allied to the Rats. It is a native of Egypt, Syria, &c. ; 

 and was known to the ancients under the name of Dipus (two- 

 footed), which it still bears as its scientific appellation. 



223. The family MURIDJE, consisting of Mice, Rats, and other 

 animals allied to them, contains the smallest, and at the same 



