THE EGYPTIAN JERBOA. 



3; 



rudiment of a thumb, furnished, however, with a nail. 

 In the hind-feet of these animals we behold palpable 

 evidences of their express adaptation to the deserts 

 where they habitually reside. Not only is the metatarsal 

 portion of the foot extremely elongated, but the toes are 

 clad on the under surface with long bristly hairs, which, 

 while they add to their span, and give firmness and se- 

 curity to their tread on a loose and yielding surface, 

 defend the foot from the heat of a glowing waste beneath 

 a fervid sun. 



19. — Egyptian Jerboa. 



The Egytian Jerboa is found in Egypt, Barbary, 

 Nubia, and the warmer parts of Syria and Arabia. It 

 lives in troops, which colonize the most arid parts of the 

 desert, where, on hillocks of sand or the crumbled heaps 

 of ruins, they work out long burrows in which to dwell. 

 In these burrows they make their nest and rear their 

 young. So powerful are their teeth, that they not only 

 gnaw in a short time through the hardest wood, but, a 

 Sonnini afTirms, through thin layers of stone beneath the 

 sand. According to some, these animals are nocturnal 



