s instance of
foresight in a weed.

I wish I could read as clearly this puzzle of the button-balls
(American plane-tree). Why has Nature taken such particular pains to
keep these balls hanging to the parent tree intact till spring? What
secret of hers has she buttoned in so securely? for these buttons will
not come off. The wind cannot twist them off, nor warm nor wet hasten
or retard them. The stem, or peduncle, by which the ball is held in
the fall and winter, breaks up into a dozen or more threads or
strands, that are stronger than those of hemp. When twisted tightly
they make a little cord that I find it impossible to break with my
hands. Had they been longer, the Indian would surely have used them to
make his bow-strings and all the other strings he required. One could
hang himself with a small cord of them. (In South America, Humboldt
saw excellent cordage made by the Indians from the petioles of the
Chiquichiqui palm.) Nature has determined that these buttons should
stay on. In order that the seeds of this tree may germinate, it is
probably necessary that they be kept dry during the winter, and reach
the ground after the season of warmth and moisture is fully
established. In May, just as the leaves and the new balls are
emerging, at the touch of a warm, moist south wind, these spherical
packages suddenly go to pieces--explode, in fact, like tiny bombshells
that were fused to carry to this point--and scatter their seeds to the
four winds. They yield at the same time a fine pollen-like dust that
one would suspect played some part in fertilizing the new balls, did
not botany teach him otherwise. At any rate, it is the only deciduous
tree I know of that does not let go the old seed till the new is well
on the way. It is plain why the sugar-berry-tree or lotus holds its
drupes all winter: it is in order that the birds may come and sow the
seed. The berries are like small gravel stones with a sugar coating,
and a bird will not eat them till he is pretty hard pressed, but in
late fall and winter the robins, cedar-birds, and bluebirds devour
them readily, and of course lend their wings to scatter the seed far
and wide. The same is true of juniper-berries, and the fruit of the
bitter-sweet.

In certain other cases where the fruit tends to hang on during the
winter, as with the bladder-nut and the honey-locust, it is probably
because the frost and the perpetual moisture of the ground would rot
or kill the germ. To beech