1886.] Causes of Forest Rotation. : 523 
The same is true (7. e., not growing their young within the radius 
of their leaf-fall) of the white pine, firs and other evergreens 
transported here for ornamental purposes. Some of the older 
ones are twenty inches in diameter, and have borne seeds many 
years, 
I have long observed that the seeds of forest trees shed upon 
the forest leaves, sugar maple excepted, cannot sprout. This is 
very specially the case with the American poplar seeds. Yet I 
often find in the woods clusters of young poplars, varying in age 
from one year to sixty and seventy years. Last year I found out 
how this comes about. If the seeds happen to fall on the bare 
ground of the right degree of moisture, they at once take root 
and grow. If about the time these seeds are falling there should 
be a hog in the woods and he should have an appetite for ground 
Worms, he would thrust his strong snout through the leaves into 
the ground and cast u p fresh earth in a very promiscuous manner, 
and every poplar (or other) seed that should happen to fall on 
that fresh ground would stand a good chance of growing. I saw 
young poplars just barely sprouted under the above circum- 
stances, while at the same time other and brother seeds had 
fallen on the leaves neat by, where they lay dead and as dry and 
crisp as smoking tobacco. are 
Sometimes squirrels, hares, ground squirrels (chipmunks) dig eae 
through the leaves into the ground for food which they find there, 
I presume, and these places give a chance for one or more seeds 
to grow, and the hoofs of heavy bullocks (and in times past the 
elk and buffalo) have made deep tracks through the leaves into 
the ground, which would give a like chance, whilst the coating — 
of leaves would prevent the growth of all the rest. The hogs were 
brought here at the very earliest time of settlement, turned loose 
In the woods, where they multiplied rapidly, becoming wild, fero- 
cious and more dangerous to man than bears, wolves or panthers. _ 
M 
© 
= „ause of its rapid growth. Many of these are ten to twenty 
: ‚aches in diameter at the butt, and have been bearing seeds for , 
PAN The seeds of this tree must find favorable growing con- 
ditions as soon as they falf or they are lost, for one day’s baking 
m the hot sun kills them. They must have a steady moisture — 
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