26 MOUNTAIN AND MOORLAND 



Before we begin the descent, let us look downwards 

 and distinguish the various zones. They differ a little 

 from hill to hill, but what do we see here ? (a) There 

 is the barren zone at the top, with its lichens and just 

 a few little plants eking out a sparse subsistence. 



(b) Then there is a zone that one might compare to a 

 big rockery. There is no heather to speak of, but 

 there are pockets among the rocks and stones where 

 a little lichen-made soil has gathered. In some of 

 these there are alpine plants, like the alpine Lady's 

 Mantle (Alchemilla alpina), with a good deal of silky 

 hair except on the upper surface of the leaves, and on 

 drier places there are the creeping stems of the Club 

 Moss (Lycopodium selago), a relic of an ancient vege- 

 tation. We may call this the Arctic-alpine zone. 



(c) Below this is the heather zone, or high moor, with 

 poor, shallow soil. We must afterwards try to under- 

 stand how the heather thrives so well where only a few 

 other plants can grow. On flat water-logged parts of 

 this zone there are peat bogs, (d) Towards the lower 

 part of the heather zone we may distinguish the hill 

 pasture. There is still some heather, but the accumu- 

 lation of more soil and the existence of drainage have 

 allowed the growth of grass, and here we see sheep. 

 (e) This passes imperceptibly into the alluvial land of 

 the valley, where there are meadows and ploughed 

 fields. It must be clearly understood that this view 

 of zones is only a sort of bird's-eye view. The matter 

 is far too complicated and subtle for our simple studies 

 here. Dr. W. G. Smith's admirable account of Arctic- 

 Alpine vegetation in Tansley's "Types of British 

 Vegetation" (1911) should be consulted by those who 

 wish to go deeper and farther. 



