I] DWARF-TREES 5 



and self-sown firs are now springing up in multitudes, so 

 close together that all cannot live. When I ascertained 

 that these young trees had not been sown or planted, 

 I was so much surprised at their numbers that I went 

 to several points of view, whence I could examine hundreds 

 of acres of the unenclosed heath, and literally I could not 

 see a single Scotch fir, except the old planted clumps. But 

 on looking closely between the stems of the heath, I found 

 a multitude of seedlings and little trees which had been 

 perpetually browsed down by the cattle. In one square 

 yard, at a point some hundred yards distant from one of 

 the old clumps, I counted 32 little trees; and one of them, 

 with 26 rings of growth, had, during many years tried to 

 raise its head above the stems of the heath, and had failed. 

 No wonder that, as soon as the land was enclosed, it be- 

 came thickly clothed with vigorously growing young firs. 

 Yet the heath was so extremely barren and so extensive 

 that no one would ever have imagined that cattle would 

 have so closely and effectually searched it for food. Here 

 we see that cattle absolutely determine the existence of 

 the Scotch fir." 



I have myself gathered a Larch on the ice-locked moraine 

 of the Aletsch Glacier, which, although only a scrubby 

 little bush of a few inches high, showed 13 annual rings 

 in its stout little stem, and had evidently been kept down 

 to this stunted condition by the pruning action of dry, 

 cutting winds combined with periodic droughts and long 

 resting periods : its root-system was long and large out 

 of all proportion to the stunted growth of the shoot- 

 system. 



It will be evident from the foregoing that any attempt 

 at rigid classification of the forms of woody plants into 

 trees and shrubs must result, in individual cases, in failure. 

 And nevertheless such terms as tree, shrub, and bush a 



