428 ALPINE AND ARCTIC PLANTS 



In ascending the mountain directly, the spruces of this zone 

 gradually degenerate, until they present the appearance of little 

 gnarled bushes, flat on top and closely matted together, so that 

 except where paths have been cut, it is almost impossible to 

 penetrate among them. Finally, they lie flat on the ground, 

 and become so small that, as Lyell remarks, the reindeer moss 

 may be seen to overtop the spruces. This dwarfing of the 

 spruces and firs is the effect of adverse circumstances, and of 

 their struggle to extend their range toward the summit. Year 

 by year they stretch forth their roots and branches, bending 

 themselves to the ground, clinging to the bare rocks, and avail- 

 ing themselves of every chasm and fissure that may cover their 

 advance ; but the conditions of the case are against them. If 

 their front advances in summer, it is driven back in winter, and 

 if in a succession of mild seasons they are able to gain a little 

 ground, less favourable seasons recur, and wither or destroy the 

 holders of their advanced positions. For thousands of years 

 the spruces and firs have striven in this hopeless escalade, but 

 about 4,000 feet above the sea seems to be the limit of their 

 advance, and unless the climate shall change, or these trees 

 acquire a new plasticity of constitution, the genus Abies can 

 never displace the hardier alpine inhabitants above, and plant 

 its standard on the summit of Mount Washington. 



I was struck by the similarity of this dwarfing of the upper 

 edges of the spruce woods, to that which I have often observed 

 on the exposed northern coasts of Cape Breton and Prince 

 Edward Island, where the woods often gradually diminish in 

 height toward the beach or the edge of a cliff, till the external 

 row of plants clings closely to the soil, or rises above it only a 

 few inches. The causes are the same, but the appearance is 

 more marked on the mountain than on the coast. It is in minia- 

 ture a picture of the gradual dwarfing of vegetation in the great 

 barren grounds of Arctic America. 



On the path which we followed, before we reached the uppei 



