SPRING FLOWERS. . 323 



freezings and thawings is, however, rather rapicl for 

 the safety even of native plants, unless the roots are 

 deep in the soil^-deeper than soil is usually found to 

 be in cold upland places. Gardeners find great pro- 

 tection to fleshy roots in the ground, from covering 

 them over with straw and litter before the frost ; 

 and the moss and lichen act, in those places where 

 they come, as if they were a coat of natural litter. 



Owing to those protections, the spring flowers, 

 though not very abundant, come much sooner in 

 those mossy places than one would expect, though 

 they neither come so soon nor are so fine in their 

 qualities as those in places which are covered with 

 snow early in the winter, and remain in that state 

 till the spring. If the snow lies long on a spot 

 where the roots are, the snow-drops will absolutely 

 push their little starry cups through it. 



But these humble crops are as serviceable in the" 

 warm season as they are in the cold. Many of them 

 absorb moisture at their whole surface, and all of 

 them retain it in their thickly matted forms, so that 

 they keep places in a moist and fertile state which, 

 but for them, would be-entirely parched. When the 

 heath has been burnt on a mountain surface, or that 

 surface in any other way laid bare, it is truly aston- 

 ishing how speedily it becomes clothed with green 

 mosses. These keep the surface cool, whereas the 

 rays of the sun, beating upon it, would heat it like an 

 oven, and it would be converted into blowing dust ; 

 and when summer rains did fall, they would be 

 instantly removed by flowing off and being evapo- 

 rated ; and although the moss presents much more 

 surface to the air than that of the soil on which it 

 grows, it is so much cooler that the evaporation from 

 it is considerably less. The absence of mosses is 

 among the reasons why sandy and chalky places are 

 so soon parched up. 



But although, within certain limits, the growth of 

 those plants is good, yet, when those limits are ex- 



