The Rivalry Of Plants To Please Us
On The Forward March of Adaptation
"We cut down our alfalfa four or five times a season," says someone, "why doesn't it grow spines to protect itself? We destroy our lettuce before it goes to seed; why doesn't it develop a protective bitterness like the sagebrush? We rob our apple trees of all their fruit the moment they are ripe; why do they not become poisonous like the desert euphorbias?"
"Let us go back to the cactus," says Mr. Burbank, "and read the answer. Grim and threatening though the cactus seems, it is not without its softer side; in the springtime its blossoms, a multitude of them, push their way through the spiny armor-and rival the rose in formation, compete with the orchid in the delicacy of their hues. No favorite garden flower can outdo this ungainly monster of the desert, when in bloom, in the seductiveness of its advertisement to the bee. When summer comes, and the bee has paid, by the service it has rendered, for the honey it has taken, the nest of fertile eggs beneath each cactus blossom begins to grow into a luscious fruit. In this cactus fruit there is an acid sweetness as tempting as that of the raspberry, the strawberry or the pineapple. Its outward covering has a brilliant beauty no less attractive than that of the cherry, or the grape. Thus, in the springtime, the cactus, like the cherry, advertises to the friendly bees to bring its offspring new heredities, and, in the fall, it advertises to the friendly birds to carry off its seed and plant it where its young may have the advantage of new environments. "In its spiny armor we read the plant's response to the enemies in its environment. In its brilliant flowers and tempting fruit we read its receptiveness to the friendship of the birds and bees. Those spines and those flowers and fruits tell us that while its ancestors were fighting a common foe, they still found time to build up lasting partnerships. And so, with every plant that grows, we shall see these same tendencies-instincts shall we call them?-to ward off the enemy and make use of the friend."
"So long as plants grow wild, the frosts, the winds, the hail storms, the droughts and the animals are principal among the enemies with which they have to reckon. So long as they grow in the woods, or on the mountains, or in the deserts, the bees and the birds and the butterflies-the warmth of the sun and moisture of the soil-these are among the friendly factors in their lives. But when we take plants under cultivation, we upset their whole environment. We build fences around our blackberries so that they need no thorns. We save the seeds of our radishes, and the bulbs of our lilies, and through human organization distribute them and plant them wherever they will grow. We cut slips from our apple trees and ship them from county to county, and state to state, and nation to nation, and zone to zone. We select, and improve, and plow, and harrow the ground for our plants; we water them when they are dry; we surround them with shade trees if they need shade, we cut down the shade trees if they prefer the sun; we plant their baby seedlings under glass, and give them every favoring condition in which to mature; we remove what for ages have been the chief problems of their lives-we take over their two prime burdens, the burdens of self defense and reproduction. The frosts, and the winds, and the hail storms, and the droughts, and the animals are no longer the chief enemies of plants; for man, when he comes into their environment, is more dreadful than all of these combined-if he chooses to destroy. And the bees and the birds and the butterflies, and the warmth of the sun, and the moisture in the soil, fade into insignificance as friendly influences when compared with that of man-if it pleases him to be a friend. So the geranium still advertises to the bees, and the cherry tree to the butterflies and birds, as of old. But their main advertisement, now, is an advertisement to us; their strongest effort, now that we have become predominant in their lives, is to lure us with their blossoms and their fruit-to enchant us with their odors, and colors, and lusciousness, as they formerly enchanted only the bees-to win and hold our appreciation and affection, and merit our kindly attention and care." Our alfalfa, lettuce and apples, like our horses, our cows, our dogs, have found in man a friend stronger than the strongest of their enemies. So their welfare now is measured by the usefulness of the service they can render in repayment for man's care.
"There is a common snowball in my yard," continued Mr. Burbank, "which advertises alone to me. In the woods around there are other snowballs of the same family-wild snowballs-into whose life history man, as a part of environment, has never come. The wild snowball, with only a fringe of blossoms, and a mass of egg nests and pollen inside the fringe, is still advertising to the bee. But the snowball in my yard has responded to my care, and to the care of those who went before me, till its stamens and pistils, as if seeing their needlessness, have turned to blossoms-till its eggs have grown sterile, even should an insect come. And so, with every snowball which grows in anybody's yard-cultivation has relieved it of the need for reproduction, and what was once but a fringe of flowers has been transformed into a solid mass of blossoms. Just as a mother cat can make a dumb appeal for the protection or the sustenance of her kittens, an appeal no human being can misunderstand, just as strongly and just as clearly do the snowballs, by the beauty and helplessness of their self-sterilized flowers, appeal to us to see to their protection and effect the perpetuation of their kind."
Many violets, as they grow wild in the woods, bear two kinds of blossoms. One is the flower, rich in color and in scent which is borne at the top of the plant. The other, an egg nest without odor, or beauty, or other advertisement-which is borne near the base of the plant. The flower at the top, like the flower of a geranium, advertises to the insects to bring pollen from other plants. The colorless flower at the bottom needs no insect to bring it pollen-it pollenates itself and produces fertile eggs with only a single strain of heredity. Some of these violets with upper and lower blossoms, particularly those which grow in the shade, never open their upper flowers-as if knowing that the friendly insects so prefer the sun that no attempt at advertisement could lure them to the shade. These violets reproduce themselves wholly by the self-fertilization which goes on within the colorless flower below. And there are those violets, of this same kind, blooming in the sunlight, which open their upper flowers, so that, if visited by insects, the seed within matures; but, as if in doubt of the effectiveness of their advertisement, the lower blossoms continue to produce their inbred seed. And there are still other violets which, as if assured of the friendship of the insects, have ceased to make the colorless blossoms below, and produce their entire output of seed at the base of the brilliant upper flower. Here, in these three kinds of violets, is written the story of a plant's struggle with wild environment in which man has not yet become a factor; the story of an unequal struggle in which the stages of failure, partial victory, and complete triumph are clearly laid before us.
Into the life of the violet, some few hundred years ago, there came the new element of environment-man. A single violet plant which was taken from its catch-as-catch-can existence, let us say, found itself in fine-combed soil in the shade of some one's dooryard. If it rained too much, drainage took up the excess. When the rains did not come, the soil was sprinkled. Under cultivation, and kindly care, the discouragements of its life grew less and less, and the encouragements to thrive grew more and more. Soon this violet, as if assured of reproduction, abandoned the blossoms at its base, and threw its energies into making bigger and brighter and more beautiful blossoms at its top. Where it had half-heartedly advertised to the bees of old, it now concentrated its efforts to win the approval of the new-found friend whose dooryard brought it opportunity. And this is the life story of that kind of violet which we now call the pansy. On the one hand, in the woods, we see its wild kin-folk still struggling against unequal odds; on the other we see its own large, beautiful pansy petals, and the increased brilliancy of its hues; each a response to environment. Truly, in the pretty face of the pansy, we may read the vivid story of man's importance as a friendly element in the lives of plants.
Where do the flowers get their colors? "From the bees," said Mr. Burbank. "And from us."
On the experiment farm at Santa Rosa, there grow two ordinary looking pear trees which amplify the thought. One of these trees produces large, juicy, soft, aromatic, luscious, easily digested pears-a delight to the eye and to the palate. The other produces small, hard, bitter, indigestible fruit, the very opposite in every way of our idea of what a pear should be. Looking at these trees side by side, it would be difficult to realize that their fruit could be so different. Both show the unmistakable characteristics of the pear tree-the pear tree shape, the pear tree branches, the pear tree leaves, the pear tree blossoms. In their fruit alone do they differ.
Since these two pear trees illustrate an important point, let us begin at the beginning: The pear, it seems, was first discovered in eastern Europe or western Asia. It was there, in Eurasia, some two thousand years ago, that man first realized that this fruit was good to eat. Coming to us, thus, out of obscurity, the pear, during these twenty centuries, has spread to the east, and to the west, till it has completely encircled the globe-a slow process, but one which takes place in every desirable fruit which is discovered or produced. As Europe became more and more settled, the pear kept pace with the invaders. It followed them to the British Isles, it followed them across the Atlantic to America. It followed them westward across this continent as the pioneers pushed their way to the Pacific. In the same way it worked its eastward journey through Siberia, and China, and Japan -more slowly, perhaps, than under the influence of European and American hurry and enterprise, but just as constantly, and just assurely-till now, in friendly climates, it is a world-wide fruit.
Both of the pear trees described here, as in fact all of the pear trees which we know today, seem to have come from those common parents in eastern Europe or western Asia. The one in Mr. Burbank's yard which bears the luscious fruit is the Bartlett pear-an excellent though common variety in the United States. The other, with its bitter, indigestible fruit, is one which was imported from Japan.
The lesson which these two pear trees teach is that fruits, like flowers, in their rivalry to please us, adapt themselves to the tastes, desires, and ideals of the human neighbors among whom they grow. Here, in America, we like fruits that are soft, large, sweet, luscious, juicy, aromatic, easy to digest when eaten raw. Our pears grow that way. In Japan and China they like fruits which are hard, small, bitter, dry, acid-suitable only for pickling, preserving, or cooking. The Chinese and Japanese pear trees bear that kind of fruit. Neither the Japanese pear, nor our American type, is like the original wild parent which was first discovered near the middle of Russia. Each has changed - one toward one set of ideals-and the other toward another set.
If we could lay bare before us the whole history of the pear tree-if we could picture in our minds its stages of progress beginning back in the times, say, when instead of a fruit it bore only a seed pod like the geranium's-we should see a record of endless change, constant adaptation. We should see that the soil, and the moisture, and the sunshine, and the air, throughout the ages, have played their parts in working the pear tree forward. We should see that other plants, crowding it for room, or sapping the moisture from its feet, or adding richness to the soil by their decaying leaves and limbs, have done their share in hastening its improvement. We should see that the bees and butterflies and birds, with their help, and the caterpillars, locusts and deer in their efforts to destroy, have all served to aid the onward march. We should see all the while a steady change for the better-sturdier pear trees, brighter blossoms, more seed, better fruit. We should see that, with the aid of the elements, the pear tree adapted itself to exist, hardened itself to withstand many soils and many weathers. We should see that, with the unintended aid of its plant and animal enemies, it gained strength through overcoming them. We should see that, through the bees, it was helped into variation by mixing up heredities; and, by the birds, it was helped into still further variation by mixing up environments. Then, overshadowing all of these influences, there came into its life new influences of man-man savage and civilized, Oriental and Occidental-man with a liking for pears. Here in America, we who have grown pears have saved those which were the sweetest, the largest, the juiciest, the most luscious-because those were the ones we liked best. When we have bought pear trees to plant in our yards, we have chosen those which would give us the kind of fruit we prefer. The pear trees which have pleased us have received our care and cultivation-and we have multiplied them. The pear trees which have failed to produce fruit up to our ideals we have neglected and allowed to die-so that they have practically disappeared from our orchards. The Orientals, their tastes and likes running in opposite directions from ours, have discouraged pear trees which bore the kind of fruit we prefer, and have selected, and saved, and fostered, and propagated those which gave them the hard, bitter fruit of their ideals. And so the struggle for adaptation set in motion by the soil, the warmth, the cold, the moisture, and the winds, was supplemented by the bees, and then by the birds, until now we can read, in the result, our own influence and that of the Japanese.
There are differences between our dress and the dress of the Orientals; between our religions and the religions of the Orientals; between our ambitions and the Oriental ambitions; between our architecture and the architecture of the Orient all reflecting the national or racial differences between the ideals of the two peoples. And just as surely as the ideals of a people influence the architecture with which they surround themselves, just as surely as they change ambitions, mold religions, create dress styles, just so surely do they influence and change the characteristics of the plantsin whose environment they live.
"When I say that man is the biggest element in the environment of plants," said Mr. Burbank, "I do not mean those few men who have devoted their lives to the improvement of plants. I do not mean the botanist, the horticulturist, the florist, the nurseryman, the agricultural experimentalist. I mean man in the mass-man busy with his dry goods store, or his steel company, occupied with his law, or his medicine, tired out from his daily blacksmithing, or his carpentering. I mean just man, the neighbor of plants, whether he be their friend or their enemy-whoever and whatever he is."
It was the savage Indian who gave us, here in America, the most important crop we have. It was the Indian who found a wild grass covering the plains and developed it into corn. Or, to turn it the other way around, it was the desire of the Indian for a food plant like this that led the teosinte grass, by gradual adaptation, to produce Indian corn or maize. On Mr. Burbank's experiment farm there grows, today, this same teosinte grass which the Indians found. It bears tiny ears with two rows of corn-like kernels, on a cob the thickness of a lead pencil, and two and a half to four inches long-slightly less in length and diameter than an average head of wheat. From its earlier stage of pod corn, in which each kernel grew in a separate husk like wheat, teosinte represented, no doubt, a hard fought survival and adaptation like that of the flowering violet. And when the Indians came into its environment it responded to their influence as the pansy responded to care and cultivation in its new dooryard home. Where teosinte had formerly relied upon the frosts to loosen up the ground for its seed, it found in the Indians a friend who crudely but effectively scratched the soil and doubled the chance for its baby plant to grow. Where it had been choked by plant enemies, and starved for air and sunlight by weeds, it found in the Indians a friend who cut down and kept off its competitors. Where it had been often destroyed by the animals before its maturity, it found the selfish protection of the savages as grateful as though it had been inspired by altruism. Planted in patches, instead of straggling here and there as best it could before, the teosinte grass found its reproduction problem made easier through the multitude of pollen grains now floating through the air. And so, by slow degrees, it responded to its new environment by bearing more and bigger seed. As the seed kernels increased in numbers and in size, the cob that bore them grew in length. From two, the rows of kernels increased to four, to six, to eight, to fourteen. Here again the selfish motives of the savages served to help the plant in its adaptation-for only the largest ears and those with the best kernels were saved for seed. So, under cultivation, the wild grass almost disappeared, and in its place there came, through adaptation, the transformed Indian corn.
"There were two wealthy men in England," said Mr. Burbank, "who took up the daffodil and the narcissus, growing endless quantities of seedlings just for amusement. Both of these men, so it happened, were bankers. One was a rather large, coarse, strong, dominating type of man-not a repulsive man by any means, but lacking, a little, in refinement and the more delicate sensibilities. The other banker was a highly sensitive, nervous, shrinking man with a great eye for detail, a true appreciation of values, a man who looked beneath the surface of things and saw beauty in hidden truths, a man who thought much and said little. These men were great rivals in their daffodil-and narcissus-growing pastime, and each of them succeeded in producing some wonderful variations and adaptations in their plants. When these bankers died, their daffodil and narcissus bulbs were offered for sale and fell into the hands of a friend of mine, Peter Barr, a great bulb expert of England. Peter Barr told me that though the bulbs bought from those two estates were mixed and planted indiscriminately on his proving grounds, he could go through a field of those daffodils and narcissus' and, simply by the blossoms, tell which had come from one estate and which from the other. The flowers that came from the bulbs that represented the work of the first banker were large, coarse, brightly colored, virile, strong flowers-with a beauty that called to the passer-by as if out loud, and a self defiant attitude as if bespeaking an ample ability to take care of themselves. And the flowers which came from the bulbs produced by the other banker were charmingly delicate-not hardy, but rather shrinkingly artistic-not loud in their color schemes, but softly alluring with their subdued hues."
It costs money to ship oranges, so the more the meat and the less the rind, the less we waste in transportation charges. A comparison of the wild orange with the cultivated fruit of our orange groves shows how this fruit has adapted itself to our ideas of economy.
Lettuce in the head makes a more appetizing salad than lettuce in large, sprawling leaves. A comparison between wild lettuce and the head lettuce on our green grocer's stand shows plant adaptation to our salad demands.
And so with celery, and artichokes-and every plant that is grown for the market-wild, its adaptations are toward meeting wild environments; cultivated, its adaptations are toward fitting itself into our routine of life. We have seen the price which variation costs; now we begin to see the value of it. Among those violets, environment-the environment of the present combining with heredity which is the recorded environment of all the past-contrived to see that there were no duplicates; that each violet, a little different from its mate, might, through its difference, be suited to a separate purpose, or fitted to carry a separate burden, or designed to fill a separate want. If the violets had been as like as pins, they would have stayed as like as pins when planted in that friendly dooryard. But because each had within it the power of transmitting variation, the power of responding, ever so little, to the trend of its surroundings, one violet became a pansy.
Among our human acquaintances we know those who are sturdy, and those who are weak; those who have well developed minds at the expense of their muscles, and those who have well developed muscles at the expense of their minds, and those with a more evenly balanced development; we know some who are tall and some who are short; some with brown eyes and some with blue; some who lean toward commerce, and some who lean toward art; and on and on, throughout an infinite number of variations, an infinite combination of those variations, each variation representing the result of present environment reacting upon all of the environments of the ages, stored away. As a people, we traveled by stage till the railroad came; and then in a single generation, because of the variation and the adaptability among us, we found surveyors to push their transits over the hills, and valleys, and streams; we found wood-choppers to make ties, we found steel makers who for the first time in their lives fashioned a rail, we found engineer, and firemen, and switchmen and superintendents, and railroad presidents, each to play his part in fulfilling the common desire for transportation, each able to adapt himself to new duties-and all because of this variation that is in us. As a people, we submitted to a ruler across the seas till among our variant individuals there arose some who, different from the rest, adapted themselves to the formulation of a declaration of independence, the framing of a code of principles, the organization of a successful revolution. As a people, threatened with the constant peril of cures which were worse than their diseases, there appeared out of the variable mass one who gave us antiseptic surgery. Where are those who, a century ago, said that railroads could never be? Where are the Tories of revolutionary times? And where are those barbers of ancient days with their cupping glasses and their lancets and their leeches? Ah, where are the pear trees of Eurasia that failed to fit into the scheme of adaptation-where are the geraniums that did not learn to advertise to the bee-and where are the desert cactus plants that could not protect themselves with thorns?
On and on we go, one step backward some- times, then two steps forward-marking time awhile, then onward with a spurt-the pear tree, the geraniums, the cactus plants, and we-each individual among us a little different from the rest, each with a separate combination of old environment stored within us, finding always an infinity of new environment to bring it out; growing up together, the pear trees, the geraniums, the cactus plants and we, all of us depending on the others, and each of us playing his separate part in the forward march of adaptation. On and on we go, because of Infinite Variation.
And so, from whatever viewpoint we approach the study of plants-whether with an eager eye to the future and the past, or whether with an eye, opened only a slit, to see simply the things we can touch and feel, we find evidences of adaptation made possible through variation. The violet, responding to kindness, became a pansy. The pear, responding to racial tastes, adapted itself to the Orientals and to us. Corn, responding to a need for food, produced forty times the kernels which it had produced before. The orange, the lettuce, the celery, and every cultivated plant that grows, responding to our market demands, have transformed themselves to meet a readier sale. And those daffodil and narcissus seedlings, how eloquently they tell of the adaptation of a plant to fit an individual ideal!
We studied electricity a long time without much apparent practical benefit. Then suddenly electric lights and trolley cars were everywhere. We knew the principles of sound vibration for centuries before the telephone and the phonograph appeared, but it took less than a generation to make them universal. We dreamed motor carriages three hundred years before we got one, and then, in a decade, we, awoke to find our dream come true. And almost from the beginning, man has studied the forces which go into the make-up of life without much encouragement, till now these ages of contemplation have begun to crystallize into thornless cacti, stoneless plums, fragrant calla lilies and a thousand other results as definite and as practical as the trolley or the telephone or the omnipresent touring car. Who among us shall say what new plants even a decade, now, may bring forth?
-On and on we go; one step backward, sometimes; then two steps forward; marking time awhile; then onward with a spurt.
This text is from: Luther Burbank: his methods and discoveries and their practical application. Volume 1 Chapter 4