138 THE CANADIAN NATURALIST. 



ing flush of green, the leaves being quite developed and open/ 

 but yet soft, small, and tender. The green is now of a very 

 light and yellow cast, but after a while it will be much 

 darker. 



C. The poplar seems to be the first tree that leafs. 



F. Yes : there may be others that burst their leaf-buds 

 a day or two before it, but they are much longer before they 

 acquire anything like foliage. I noticed the bursting of the 

 leaf-scales in those woods about a week ago, but some near 

 the village are more forward by several days. We often find 

 a difference of many days in the leafing of trees of the same 

 species in different situations, which, for aught we can see, 

 appear equally favourable. The Poplars (Populus tremu- 

 loides, P. grandidentata, P. Icevigata, Stc.J are very rarely 

 seen in the primitive forest : but if a clearing be made, and 

 neglected for a few years, the ground will be covered with a 

 new growth of trees, usually called " second growth timber," 

 consisting almost wholly of poplars, provided the land be 

 slightly disposed to wetness. The cause of this I cannot in 

 anywise explain. It is not confined to the case I have men- 

 tioned : it has very often been observed that when forests 

 are destroyed, they are succeeded by a spontaneous growth 

 of plants of altogether different species from those which 

 originally occupied the ground. How are they produced? 

 From seed, certainly : but whence comes the seed ? has it lain 

 in the ground for uncounted ages, waiting a favourable op- 

 portunity to spring up ? I cannot tell ; this is one of those 

 mysterious things, which I am not at all adequate to unfold. 

 I can only notice the fact. 



C. Is not the Balm of Gilead a species of poplar ? 



F* It is : Populus Balsamifera is its botanical appella- 

 tion. This tree affords a good example of the perules, or 

 scales, which serve as a sheath to the bud in winter, and 

 which protect the tender, unexpanded leaves within from 



