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 f Populus tremu- 
loideSy P. grandidentata, P. Icevigata, Sic. 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 Balsamife7^a 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 
