HIGH LIFE. 99 



like, they seldom rise above the level of the rocks and 

 stones, whose interstices they occupy. It is this combina- 

 tion of characters that makes mountain plants such 

 favourites with florists : for they possess of themselves 

 that close-grown habit and that rich profusion of clustered 

 flowers which it is the grand object of the gardener by 

 artificial selection to produce and encourage. 



When one talks of the ' the limit of trees ' on a 

 mountain side, however, it must be remembered that the 

 phrase is used in a strictly human or Pickwickian sense, 

 and that it is only the size, not the type, of the vegetation 

 that is really in question. For trees exist even on the 

 highest hill-tops : only they have accommodated them- 

 selves to the exigencies of the situation. Smaller and 

 ever smaller species have been developed by natural 

 selection to suit the peculiarities of these inclement spots. 

 Take, for example, the willow and poplar group. 

 Nobody would deny that a weeping willow by an English 

 river, or a Lombardy poplar in an Italian avenue, was as 

 much of a true tree as an oak or a chestnut. But as one 

 mounts towards the bare and wind-swept mountain 

 heights one finds that the willows begin to grow down- 

 ward gradually. The ' netted willow ' of the Alps and 

 Pyrenees, which shelters itself under the lee of little 

 jutting rocks, attains the height of only a few inches ; 

 while the 'herbaceous willow,' common on all very 

 high mountains in Western Europe, is a tiny creeping 

 weed, which nobody would ever take for a forest tree by 

 origin at all, unless he happened to see it in the catkin- 

 bearing stage, when its true nature and history would 

 become at once apparent to him. 



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