420 



VERTEJJRATA. 



JERBOAS. 



Alactar/a, and Acontion, but we shall group them under the single genus, JERBOA, Dipus. These 

 animals have the head large and rabbit-like; the ears long and pointed; the eyes full; the tail 

 \ vry long, covered with short hair and tufted at the end, this member being used in leaping and 

 walking; the fur is soft and delicate ; the fore-feet are very small ; the hind-legs are long, and the 

 hind-feet large and strong, and covered with hair. They seem expressly designed to live on 

 desert wastes, where they are usually found. Four species are known. 



The Gerbo, or Egyptian Jerboa, D. sagitta, seems to have excited the curiosity of man- 

 kind from the earliest times. Aristotle speaks of it as an Egyptian rat that walks on two feet, 

 and Pliny calls it a walkinrf-bijjed. In size it is equal to a small rat, the body being five inches 

 long and the tail seven ; the general color is a pale tawny-yellow, passing into a lighter tint, and 

 finally into white below. It is found in Egypt, Nubia, parts of Syria, and Barbary, living in troops 

 on the arid deserts, digging long burrows in heaps of sand, and often amid crumbling ruins. In 

 these burrows they make their nests and rear their young. Their food consists of grain, bulbous 

 roots which they dig up with their fore-paws, and of other vegetables. They hibernate, but arc 

 dormant for only a short time. Their flesh is unsavory, but is still eaten. When undisturbed, 

 their common manner of sitting is on their haunches, their short fore-paws hanging down like 

 those of the Kangaroo. So powerful arc their teeth that they speedily gnaw through the hardest 

 wood. They are partially nocturnal in their habits, are exceedingly timid, and hasten to their 

 burrows upon the slightest alarm. So great is their speed in living across a plain that they will 

 outstrip a greyhound. In making each leap they spring from the hind-feet, the impetus b< 

 given by the powerful muscles of the thighs, while the tail serves as balance and rudder. So es- 

 sential is the tail, that when deprived of it the animal seems to be afraid to leap, and indeed to 

 have lost its power. In springing, the fore-paws are pressed close to the breast; the\ descend, 

 however, upon them at cadi bound, bu1 such is the celerity of the movement that the eye is de 

 ceived, and the ton-paws seem not to be used at all in the act of running. 



The Dare-banded Jerboa, 1). /W/V/z.v, is thus described by General Ilardwickc: "These ani 

 mals are very numerous about cultivated lands, and are particularly destructive to wheat and bar 

 ley crops, of which they lay up considerable hoards in spacious burrows near the scenes of then 

 plunder. They cut the culms of the ripening corn just beneath the ears, and convey them thu? 

 entire to one common subterraneous repository, which, when rilled, they carefully close, and do 

 not open for use till supplies abroad become distant and scarce. Grain of all kinds is their favor- 

 ite food; but in default of this they have recourse to the roots of grass and* other vegetables. 

 About the close of day they issue from their burrows, and traverse the plains in all directions t< 



