Il6 TEXT-BOOK OF ZOOLOGY 



sharply into the feet, and raised in the course of the day to furnace- 

 heat. A horse would sink in it, and severely injure his feet. The 

 camel, on the other hand, in spite of its own weight and the load it has 

 to bear, strides lightly across it ; for it does not, like other ruminants 

 • and the horse, touch the ground merely with its hoofs, but with broad, 

 callous soles or pads of horny integument beneath the terminal joints of 

 the two middle toes, which alone are present. These soles, in front of 

 which are the small hoofs or nails, form broad surfaces of support, which 

 prevent the animal from sinking in the soft soil, and thus also protect 

 the hairy portions of the legs from injury. The soles, being very hard, 

 are insensible both to the sharpness and heat of the sand, and being, 

 moreover, as elastic as springs, render the walk of the animal light in 

 spite of the apparent clumsiness of its feet. 



3. The fiery globe of the sun is setting on the unclouded horizon. 

 The time of repose approaches for the caravan. The camels sink down 

 to be relieved of their burdens. The callous pads with which they are 

 famished on the chest and at the joints of the legs serve them while 

 resting as protecting cushions against the sharp, hot sand. 



4. As the camel lies on the ground with outstretched neck and head, 

 we can clearly see that the pale-yellow or brown colour of its skin is 

 scarcely distinguishable from the soil. At a distance, a camel at rest 

 is said to be indistinguishable from a block of stone. (As in the case of 

 all domestic animals — see cat — examples are found here also which do 

 not possess this protective colouring.) 



5. The travellers now open the sacks of fodder ; but the animal's 

 wants are few and easily satisfied ; a few handfuls of grain or beans, 

 constitute the whole day's provisions. What it needs beyond this for 

 subsistence it has to seek for itself. (Why cannot the travellers take 

 large stores of provisions with them ?) 



6. Here and there in the desert a bundle of tough, sharp-cutting 

 grass sprouts up from the sandy soil, or a few shrubs, weeds, or trees 

 prickly with thorns are to be seen. No other domestic animal could 

 feed on these (why not ?), but the camel is provided — 



(a) With lips insensible to pain, and movable, with which it breaks off 

 the thorniest branches and plucks the sharpest grasses, afterwards 

 crushing them up in — 



(b) Its hard-skinned mouth. Prom the report of an old and ex- 

 perienced traveller in the desert we may conceive some notion of the 

 insensibility of the animal's lips, palate, and tongue. He says : " I 

 once trod on a thorn which penetrated the sole of my boot, the great 

 toe, and even the upper leather ; and it is thorns like this which the 

 camel chews up in its mouth with the utmost indifference." 



