Deserts 1 1 1 



a most valuable tree the ' mesquite ' is, not only for 

 fuel, fences, and for the framework of houses, but for 

 food. Its light foliage takes the place of grass during 

 the hot season, while its beans supply the cattle with 

 abundant food in winter ; and it is enabled to bear the 

 drought by the fact that it has huge roots, which weigh 

 hundreds of pounds when the tree is only a few feet 

 high. 



But the Prickly Pear cactus is almost equally useful, 

 so far as the cattle are concerned, and it covers 

 prairies so vast that the supply is simply inexhaustible. 

 In spite of drought, and heat, and dry soil, the thick 

 stem-like leaves, or leaf-like stems, hold an enormous 

 quantity of moisture, and when the thorns have been 

 burnt off even sheep can live and grow fat upon it. 

 For horses and cows it is split open, and they eat out 

 the inside, which is so succulent as to answer the 

 purpose of drink as well as food. One can hardly 

 imagine any other way in which water could be so 

 successfully stored in these arid districts as within the 

 thick leathery skin of the cactus. 



But the gourd family are almost as wonderful in the 

 way in which they manage to appropriate and keep 

 possession of water, even under the driest circum- 

 stances. 



A pumpkin is all water, with the exception of five 

 and a half per cent, of its weight ; and yet large pump- 

 kins may be seen growing in what looks like nothing 

 but sand. To be sure, their thick rinds enable them to 

 keep the water when they get it, and sand is liberal in 

 the way of parting with its moisture ; but even so, 

 knowing how very watery they are, it is strange to see 

 them growing in such dry soil. Plants of this kind, 



