for me to describe in full detail, though they form a delightful
subject for individual study in any small suburban garden. I will only
give one more illustrative case, just to show the sort of point an
amateur should always be on the look-out for. There is an extremely
common, though inconspicuous, English weed, the mouse-ear chickweed,
found everywhere in flower-beds or grass-plots, however small, and
noticeable for its quaint little horn-shaped capsules. These have a
very odd sort of twist or cock-up in the middle, just above the part
where the seeds lie; and they open at the top by ten small teeth,
pointed obliquely outward for no apparent reason. Yet every point has a
meaning of its own for all that. The plant is one that lies rather
close upon the ground; and the effect of this twist in the capsule is
that the seeds, which are relatively heavy, and well stored with
nutriment, can never get out at all, unless a very strong wind is
blowing, which sweeps over the herbage in long quick waves, and carries
everything it shakes out for great distances before it. So much design
have even the smallest weeds put into the mechanism for the dispersion
of their precious seeds, the hope of their race and the earnest of
their future!

Artillery marks a higher stage than the sling and the stone. Just so,
in many plants, a step higher in the evolutionary scale as regards the
method of dispersion, the capsule itself bursts open explosively, and
scatters its contents to the four winds of heaven. Such plants may be
said to discharge their grains on the principle of the bow and arrow.
The balsam is a familiar example of this startling mode of moving to
fresh fields and pastures new: its capsule consists of five long
straight valves, which break asunder elastically the moment they are
touched, when fully ripe, and shed their seeds on all sides, like so
many small bombshells. Our friend the squirting cucumber, which served