PLANTS OF THE MOORLAND in 



cases under our eyes the peat bog is passing. Messrs. 

 Lewis and Moss discuss the degeneration or retro- 

 gression of the moorland in Mr. Tansle/s "Types 

 of British Vegetation." In times of drought the 

 beds of channels among the peat become more or 

 less dry; the banks crumble; the wind removes dust; 

 the channels are widened. Rain-storms come, the 

 channels are flooded; large quantities of peat are car- 

 ried away; the streams cut back into the peat plateau 

 and wash down to the rock below. Tributary streams 

 and networks of channels are formed; the peat moor 

 is "divided up into detached masses of peat (known 

 as 'peat hags'), and the final disappearance of these 

 is only a matter of time." All things flow, peat bogs 

 and all. 



The destruction of trees by man, by fire, by wind, 

 and other agencies, may involve (i) a loss of the char- 

 acteristic vegetation on the ground of the forest, 

 (2) an accumulation of raw humus, (3) a disappearance 

 of earthworms, (4) an invasion of the area by Ling, 

 and so on. But happily there is the possibility of 

 more hopeful successions. The careful draining of 

 the moorland, the letting in of water rich in certain 

 salts, the use of lime, and other expedients, may re- 

 claim a Heather-covered tract into the service of man. 

 Professor Warming writes : " Even one year after the 

 commencement of irrigation Ling vanishes, and after 

 a lapse of three years the Heath may be replaced by 

 a carpet of Grass, and the soil may be inhabited by 

 earthworms" ("GEcology of Plants," 1909, p. 363). 



