XEkOPHYTES AND HALOPttYTES. 245 



ably by the difficulty of securing a suitable water supply. 

 They grow near the ocean, upon the shores of salt lakes, by 

 salt springs, and in the interior of the great continents in old 

 lake basins in which the salts have accumulated by the rains. 

 A few of the halophytes are trees and shrubs, with leathery 

 leaves, but almost all are succulents. In habit they are gener- 

 ally low, often creeping, with thick, fleshy, and more or less 

 translucent leaves and stems, containing comparatively little 

 chlorophyll and abundantly supplied with water, and the 

 surface generally smooth. 



345. Summary.- — Drought plants adapt themselves to a 

 scanty supply of water by (a) reducing the transpiration, (V) 

 providing means of securing water, or (c) by storing water. 

 Reduction of transpiration may be secured by periodic or 

 permanent reduction of evaporating surface, by avoiding di- 

 rect light, by water-proof or wax-covered skin, by mucilage in 

 the cells ; or by obstructing the stomata with coverings of 

 scales or hairs. Adaptations for securing water are special 

 absorbing organs on aerial parts, cuplike parts for holding 

 water, and long roots to reach deep soil water. Adaptations 

 for water-storage are water-holding substances in the cells, 

 cell specialized as water reservoirs, and thickened shoots such 

 as tubers and bulbs. 



Salt plants are mostly succulents, and show adaptations 

 similar to the drought plants. 



