204 NATURAL HISTORY ESSAYS 



seldom bite, though an escaped jerboa which 

 has run into a hole will nip the finger if 

 grasped incautiously : they often grunt if dis- 

 turbed when asleep. 



Few persons, on viewing the disproportionate 

 length of the fore and hind limbs in these animals, 

 would suppose them to be good climbers. Never- 

 theless, scrambling up the wire fronts of their 

 cages is a favourite amusement of captive indi- 

 viduals, and they will jump off quite recklessly 

 when they have climbed up as high as they 

 can. A fine female who broke her leo- from 

 this habit persisted in struggling up again with 

 one limb rendered useless, and in spite of this 

 wilful behaviour did not die for a week 

 after the injury, eating well, and hopping about 

 during the interval. Jerboas can climb curtains, 

 and they will also scramble down from a consider- 

 able height, as if trusting to the sand of the 

 desert which they once inhabited, to break their 

 fall. 



A mysterious disease is quite prevalent amongst 

 jerboas. The affected animal becomes pro- 

 gressively emaciated week by week, though it 

 still runs about as usual, and will feed even up to 

 within twenty-four hours of its death. The fur 

 in good health is wonderfully sleek and glossy : 

 in sickness the coat becomes rough and staring, 

 and though the wasting of the body may not be 



