SEASON OF REST. 99 



the plants of tropical and of temperate climates. In 

 temperate climates the cold and wet of autumn and 

 winter strip the trees, and reduce the greater part of the 

 vegetable kingdom to a state of torpor. Between the 

 tropics* the same effect is brought about by the heat 

 and drought of summer. The leaves of tropical trees 

 (within certain parallels) are burned off the branches, 

 while buds, coated with hard scales, are formed, that 

 preserve the embryo foliage till the return of genial 

 showers shall call forth the dormant powers of life. A 

 tropical forest, so stripped, has much of the aspect of a 

 wintry one in a temperate climate ; and, physiologically, 

 the condition of vegetation is the same. But, what can be 

 more opposite than the atmosphere the light through 

 which the pictures are seen ? The snow-clad earth, the 

 clear and bracing air, and a dark-blue sky of a cli- 

 mate like that of Norway or Canada, contrast strongly 

 with the burnt-up, dusty soil, air like the breath of a 

 furnace, the hazy distance in which every object dances 

 with a flickering motion, and the fierce heat that pours 

 down from a pale blue sky. Yet the effect on vege- 

 tation is the same : a season of rest is provided in 

 either case, which is absolutely necessary to ensure 

 the healthy growth of the plants of these opposite 

 climates. 



Close along the margin of the sea, either above or 

 below high-water-mark, may be seen on most rocky 

 shores, small circular somewhat scurfy patches, consist- 

 ing of minute, rigid, branching plants. These, when 

 dry, look perfectly black, but on the return of moisture 



* See Gardner's " Travels in Brazil," p. 242, &c. 



