umbers in the northern part
of the United States. How well they will prosper in this new, more
variable and chilly climate remains to be seen, but the start is made.
No doubt it will be by Johnny's old method of patient and repeated
selection, first for hardiness then for quality, that the planned result
will be accomplished.

The contributions of Persia and the plantings of its forgotten
scientists have here merely been touched on. Nothing, for instance, has
been said about her great groves of mulberry trees, which led to
silk-worms, which led to silk, which led to the production of
jewel-bright vegetable dyes, which led to the development of a
decorative art in fabrics that is rivaled by China, alone, in all the
world. And of course, Aryan Persia is only one of the many treasure
centers of ancient civilization. In scores of racial settlements
elsewhere our lives today are being changed and enriched in innumerable
ways by the hands of those old miracle-workers whose names were writ in
water and whose works are immortal. The accomplishments of China are of
such magnitude that even now we are only beginning to discover our debt
to her. India, Indo-China, Mongolia, Manchuria, Japan--all have similar
backgrounds. Even in the United States, young as it is, the migrations
of pre-historic races have left their trails in the gardens and forests
around us. Pecans from the South, for example, have been carried North
and are gradually developing hardy strains that survived in Indiana and
Illinois groves.

Enough has been said to blaze the way to the end at which I have been
driving. It may begin to look as though modern plant explorers have now
followed the plant-spoor of human migrations to their final limits. It
may look, too, as though the ends of these converging trails will find
civilization at last firmly established. Or will they?

The future race, let us admit, may eventually be able, by means of an
almost unthinkable development of food, clothing, building and medical
supplies of a synthetic or semi-synthetic nature, to dispense with some
of the agriculture we know. This is the prediction of some scientists.
Let it stand. What then is to be done with the land upon which our food
crops had formerly been raised? Manifestly, it must again be covered
with hurricane-control, flood-control, and erosion-control vegetation,
chiefly trees, perhaps. Trees for safety's sake, trees for beauty's
sake, for recreation's sake, trees