*' rv, 



THE PINE. 27 



which, in that country, are both heavy and frequent, 

 are gradually rotted near their roots, and fall, gene- 

 rally, by the action of the south-west winds, which 

 are the most violent in the British isles. After the 

 trees have fallen, and have been soaked by the rains, 

 they are soon covered by various species of fungi. 

 When these begin to decay, the rain washes the 

 adhesive matter into which they are reduced between 

 the fallen tree and the ground, and a dam is thus 

 formed which collects and contains the water. When- 

 ever this takes place, the surface of the stagnant 

 pool, or the moist earth, becomes green with mosses, 

 and these mosses further retain the water. It is a 

 property of those species of moss which grow most 

 readily in cold and moist districts, to keep decom- 

 posing at the roots while they continue to grow vigo- 

 rously at the tops. Cold and humidity, as has been 

 said, are the circumstances in which the mosses 

 that rot and consolidate into peat are formed; and 

 when the mosses begin to grow, they have the power 

 of augmenting those causes of their production. 

 The mossy surface, from its spongy nature, and from 

 the moisture with which it is covered, is one of the 

 very worst conductors of heat; and thus, even in the 

 warmest summers, the surface of moss is always com- 

 paratively cold. Beside the spongy part of the moss, 

 which retains its fibrous texture for many years, there 

 is a portion of it, and especially of the small fungi and 

 lichens with which it is mixed, that is every year re- 

 duced to the consistency of a very tough and reten- 

 tive mould. That subsides, closes up the openings 

 of the spongy roots of the moss, and renders the 

 whole water-tight. The retention of the water is 

 further favourable to the growth of the moss, both 

 in itself, and by means of the additional cold which 

 it produces in the summer. 



The following account of the conversion of forests 



