THE FORMATION OF FORESTS 105 
course, disproves the notion that frost is necessary 
for the germination of hard-shelled seeds. 
If seeds are bunched together in piles or bins, they 
must be turned frequently to prevent fermentation. 
Chestnuts, walnuts, and similar seeds must be packed 
in light dirt or sand during the winter. The outer 
husks should be removed. In the case of black wal- 
nuts, the seed may be easily hulled in a common corn- 
sheller. 
The source of seeds is a matter of great impor- 
tance. They should come from mature, healthy, 
quick-growing trees. Bad as well as good qualities 
may be transmitted. Never select seeds from stunted 
trees or trees with twisted fiber. Unfortunately, it 
is these abnormal trees which ordinarily produce the 
largest amount of seed. The more adverse the con- 
ditions, up to a certain limit, of course, the stronger 
the effort on the part of the tree to reproduce its 
kind. On high mountains, where the season is so short 
that there is insufficient warmth for seed production, 
except at rare intervals, the spruce and balsam re- 
produce themselves by shoots from the lower 
branches which have become covered with moss. This 
is a process of natural layering. It is not uncommon 
to find trees which have borne an immense amount 
of seed and have died the following year. Some may 
claim that the tree died in consequence of excessive 
