DROUGHT. 187 



The first symptoms of drought are manifest in the wilt- 

 ing of the grasses, and other rough-leaved and fibrous- 

 rooted plants. Of all perennials, the grasses are the least 

 able to bear continued heat and drought ; hence the almost 

 entire absence of this tribe of the vegetable kingdom in 

 the tropics, and their scarcity in all latitudes below tlie 

 temperate zone. Almost at the same time with the grasses 

 the tender annuals begin to wilt and droop in the gar- 

 dens. Among our common weeds, the Eoman wormwood, 

 the goosefoot, the mustard, and the wild radish feel its 

 effects at an early period. Their leaves become drawn 

 up, they gradually lose their verdure and freshness, and 

 do not increase in growth. Of the annuals, those suffer 

 the least which have a succulent leaf and stem, like the 

 portulacca and the sedum. All the rough-leaved species, 

 like the aster and the hibiscus, are among the first plants 

 that suffer and perish. 



As the drought proceeds, the grass fields in the uplands, 

 where the soil is thin and meagre, become dry and yel- 

 low ; and the clover, the whiteweed, and the saxifrage are 

 made conspicuous by their green tufts, which retain their 

 verdure after the grasses are completely seared. At the 

 same time the foliage of young trees loses its lustre, 

 and is often partially tinted by premature ripeness and 

 decay. The unripened fruits drop constantly from the 

 trees, and the new foliage that is put forth is pale, as if it 

 had suffered froni a deficiency of light. The fruits of the 

 season ripen before they have attained their fulness ; the 

 whortleberries are withered and dried like pepper, and 

 their foliage is rolled up and crisp. The air contains no 

 moisture, and the hygrometrical lichens upon the rocks 

 and hills are crusty, and break and crumble under our 

 feet, even after sunset. 



The lowlands begin to suffer after the uplands seem 

 to be past redemption, llivers have shrunk to rivulets, 



