Effects of a Silver Frost on Trees. i 29 



might expect that the changes in the outward appearances of 

 many of its mammals and birds would go hand in hand. As to 

 plants, no doubt the thicker bark of the birch trees, and also 

 their more stunted forms as met with on high elevations and in 

 high latitudes, are provisions of nature in order to protect them 

 from cold and exposure. I think, moreover (although my 

 observations were not completed to my satisfaction when I 

 left), that the hard and soft wood trees of New Brunswick, 

 growing in places much exposed to the cold north-west winds 

 of winter, have relatively thicker outer coverings than the same 

 species growing in sheltered situations; whilst the conifers 

 especially show under these circumstances a remarkable ten- 

 dency to gather moss, which, although no doubt a protection 

 to the tree, is seemingly injurious to its growth. During the 

 very severe winter of 1867 I noticed that many foreign trees, 

 such as acacias, growing in the open, and even rose bushes 

 which had been in a flourishing state, were killed outright 

 through the cold, whilst other trees had only the branches on 

 their tops damaged. During early spring the following is not 

 a rare occurrence : a shower of rain is rapidly succeeded by 

 severe frost, called " silver frost," when the bare boughs of the 

 deciduous-leaved trees and evergreens become encrusted with 

 ice, presenting a very striking and beautiful appearance in sun- 

 light, just as if they were composed of as many twigs of crystal, 

 sparkling most splendidly. But the effect is often fatal to the 

 garden fruit trees, and such as are not natives of the region. 

 I was assured by a gentleman of much experience in horticul- 

 ture, that the plum trees introduced into the province from 

 Europe rarely produce fruit, and seem to deteriorate rapidly 

 into stunted forms, gnarled and covered with excrescences. 

 The effects of the cold winters and hot summers of Canada 

 are, however, notorious with respect to such as, for instance, 

 the apple tree, which has at length got so acclimatized that 

 individuals imported to England, although seemingly not 

 affected by the change in any way, cannot be got to produce 



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