The Fall of the Leaf. 535 



enous species. It may be explained by supposing that the 

 leaves of a plant from a more southern latitude, or from a 

 country, like England, with a longer growing season, require 

 a longer time to arrive at maturity, and that their power of 

 resisting frost consists in their greater vitality. On the same 

 principle we may explain the fact, very commonly observed, 

 that a second growth of leaves, sometimes put forth after the 

 first growth has been completed, has a remarkable power of 

 resisting the action of frost. Whatever may be the explana- 

 tion, it is true that the early frosts of autumn, that cause the 

 leaves of many of our indigenous trees to drop to the ground, 

 produce no visible effect on some of the exotics : nor do the 

 intense rays of an American sun color them as they do the 

 leaves of our own trees. 



The beautiful tints of autumnal foliage are not correctly 

 attributed to the action of frost. Neither are they the effect 

 of the maturity, but rather of the old age of the leaf; and 

 they may often be observed as early as August in those trees 

 which are in a declining state of health. While passing by 

 the Salem common during the second week in August, I 

 observed a maple in its full autumnal drapery of crimson. 

 On examining it I found that the tree had been nearly girdled. 

 The wound had been healed, and left only a narrow strip of 

 bark, about three inches in width to sustain the whole plant. 

 This might have been sufficient for that purpose, during a 

 moist summer : but on account of the drought of the preceding 

 July, it failed to supply the tree with sustenance, and a pre- 

 mature old age of the leaf and its accompanying tints were 

 the consequence. A severe frost at that early date would 

 have produced no such effect. An early frost always injures 

 these tints by searing and embrowning the leaves which are 

 exposed to it. This effect was noticed last autumn (1853) 

 when the leaves that ripened later than usual, on account of 

 long continued rains in the latter part of summer, were over- 

 taken by two very severe frosts, before they had begun to be 

 tinted. In October, the effects of these frosts were apparent 

 in a brownish tinge on the outer surface of the trees, greatly 

 impairing the lustre of their tints, which were not so brilliant 

 as usual. 



