CULTIVATED PLANTS
“Three modes of plant-propagation are in use among horticulturists,
namely: layering, slipping, and grafting. To get an adequate notion of
the great usefulness of these operations let us dwell for a moment on
the origin of our cultivated plants.
“You perhaps imagine that from the beginning of time, in view of our
need of food, the pear-tree was eager to bear large fruit, plump and
juicy; that the potato, just to accommodate us, stuffed its big tubers
with farinaceous matter; that the cabbage, in its desire to gratify us,
conceived the idea of gathering those beautiful white leaves into a
compact head. You imagine that wheat, pumpkins, carrots, grapes, beets,
and no one knows what besides, possessed with a great interest in man,
have always worked for him of their own accord. You think that our
grapes of to-day are like those from which Noah extracted the juice
that made him drunk; that wheat, ever since it appeared on the earth,
has never failed to yield its annual harvest of grain; that the beet
and the pumpkin had at the beginning of the world the plumpness that
makes them prized by us now. You imagine, in short, that our
food-plants came to us originally just as we have them now. Undeceive
yourselves: the wild plant is usually of very little nutritive value to
man. His is still the task of so cultivating it as to derive advantage
from its natural aptitudes by improving them.
“In its native country, on the mountains of Chile and Peru, the potato
in its wild state is a poor diminutive tuber about as large as a
hazel-nut. Man takes the worthless wild stock into his garden, plants
it in rich soil, tends it, waters it; and behold, from year to year the
potato thrives more and more, gaining in size and in nutritive
properties, and finally becoming a farinaceous tuber as large as your
two fists.
“On the sea-coasts, exposed to all the winds that blow, there grows a
wild cabbage with a tall stalk and a few green leaves of bitter taste
and rank odor. But beneath its rude exterior it may perhaps hide
invaluable aptitudes. Apparently this suspicion occurred to him who
first, so long ago that the record of it is lost, took the sea-coast
cabbage under cultivation. The suspicion was well-founded. The wild
cabbage has been improved by man’s incessant care: its stalk has become
firmer and its leaves have multiplied, whitened, acquired tenderness,
and massed themselves in a compact head, so that we have the crisp and
succulent cabbage of to-day as the admirable result of this notable
metamorphosis. There on the sea-coast rock was the first beginning of
the excellent plant; here in our gardens is its present attainment. But
what about its intermediate forms which, through the centuries, marked
the gradual development of the species to its present high state of
perfection? Each of these forms was a step forward, and each had to be
preserved, kept from degenerating, and made the subject of still
further improvement. Who could tell the story of all the labor and
pains it has taken to produce the cabbage-head as we now have it?
“And the wild pear-tree—are you acquainted with it? It is a frightful
bramble-bush, all bristling with sharp thorns; and the pears
themselves—a most repellent fruit, sure to choke you and set your teeth
on edge—are very small, sour, hard, and full of grit that reminds one
of gravel-stones. Surely he must have had an extraordinary inspiration
who first pinned his faith on this crabbed specimen of underbrush and
foresaw in the remote future the butter-pear on which we regale
ourselves to-day.
“In the same way, by the painstaking culture of the primitive vine,
whose grapes were no larger than our elderberries, man has, in the
sweat of his brow, developed the luscious fruit of the modern vineyard.
From some poor species of grass now forgotten he has also produced the
wheat that to-day supplies us with bread. A few wretched herbs and
shrubs, far from promising in appearance, he has cultivated and
improved until they became the vegetables and fruit trees so prized by
us at present. This old earth of ours, in order to make us work and
thus fulfill the law of our existence, has behaved to us like a harsh
stepmother. To the birds of the air she gives food in abundance, but to
us she offers of her own free will nothing but wild blackberries and
sour sloes. But let us not complain, for the stern struggle with
necessity is precisely what constitutes our grandeur.
“It is for us, by our intelligence and labor, to work our way out of
the difficulty; upon us it is enjoined to put into practice the noble
creed, God helps those who help themselves.
“Thus from the earliest times it has been man’s study to select from
the countless forms of vegetation at his disposal those that best lend
themselves to improvement. The greater number of species have remained
useless to us, but others, predestined no doubt, and created especially
with a view to man’s needs, have responded to our efforts and acquired
through cultivation qualities of prime importance, since our sustenance
depends on them. Nevertheless the improvement attained is not so
radical that we can count on its permanence if our vigilance relaxes.
The plant always tends to revert to its primitive state. For example,
let the gardener leave the headed cabbage to itself without
fertilizing, watering, or cultivating it; let him leave the seeds to
germinate by chance wherever the wind blows them, and the cabbage will
quickly part with its compact head of white leaves and resume the loose
green leaves of its wild ancestors. In like manner the vine, set free
from man’s constant attention, will degenerate into the little-esteemed
wild species that haunts our hedge-rows and yields a scant harvest that
will not, all together, be worth a single bunch of cultivated grapes.
The pear-tree, if neglected, will again be found on the outskirts of
our woods, once more bristling with long sharp thorns and bearing
under-sized and extremely unpalatable fruit. Under like conditions the
plum-tree and the cherry-tree will bear nothing but stones covered with
a sour skin. In short, all the riches of our orchards will in similar
circumstances undergo such deterioration as to be worthless to us.
“This reversion to the wild state occurs even under cultivation and in
spite of efforts to prevent it when seed is used for propagating the
plant. Suppose the seeds from an excellent pear are put into the
ground. Well, the trees that spring from those seeds will bear for the
most part only mediocre or poor, even very poor, pears. Another
planting is made with the pits of the second generation, and the result
shows still further decline. Thus if the experiment is continued with
seeds taken each time from the immediately preceding generation, the
fruit, becoming smaller and smaller, bitterer and harder, will at last
return to the sorry wild pear of the thicket.
“One more example. What flower equals the rose in nobleness of
carriage, in perfume and brilliant coloring? Suppose we plant the seeds
of this superb flower; its descendants will turn out to be miserable
bushes, nothing but wild roses like those of our hedges. But we need
not be surprised at this. The noble plant had the wild rose for
ancestor, and in trying to propagate it by its seed we have simply
caused it to resume its native characteristics.
“With some plants, let us note in conclusion, the improvement attained
by cultivation is more stable and persists even when the seed is used
for purposes of propagation; but this persistence is only on the
express condition that our vigilance shall not relax. All plants, if
left to themselves and propagated by seed, revert to the primitive
state after a certain number of generations in which the
characteristics imposed by human skill and care gradually disappear.”