ARABIAN AND BACTRIAN CAMELS. 115 



this storehouse consists of one or two large collections of fat, 

 stored up in ligamentous cells supported by the spines of 

 the dorsal vertebrae. When the camel is in a region, of fer- 

 tility, the humps grow plump and expanded ; but after a 

 protracted journey in the wilderness they become shrivelled 

 and reduced to their ligamentous constituents, in conse- 

 quence of the absorption of the fat." 



The two humps of the camel, however, are smaller than 

 the one of the dromedary. Nor is he capable of so much 

 endurance : while the Arabian camel can exist without 

 water for six or even seven days, the Bactrian requires to 

 renew his supply in three. He is somewhat taller in 

 stature, however ; while his colour is generally a dull 

 brown, sometimes verging upon black, sometimes paling 

 into a dingy white. In all other respects, — in his general 

 conformation, in the long neck which raises his head high 

 above the hot and dusty soil, in the valve-like nostrils that 

 close instinctively against the minutest grain of sand, in 

 the wide cushion-like feet so well adapted for treading the 

 irregular surface of the desert, — we see that he is eminently 

 fitted for his "mission" as the beast of burden of the waste 

 and the wilderness; able to accomplish long journeys with- 

 out fatigue and without feeling the need of frequent re- 

 freshment. 



In the high plains and table-lands by which the Eastern 

 steppes attain to the lofty level of Tibet we find the Kiang, 

 or Wild Ass ; sometimes, though erroneously, called the 

 Wild Horse, because its call resembles tlie equine neigh 

 more than the asinine hraij. It is a large animal, measuring 



