Twenty Three Potato Seeds and What They Taught
A Glimpse At The Influence of Heredity
The springtime buds unfold into leaves before our eyes-without our seeing them unfold. We have grown accustomed to look for bare limbs in March; to find them hidden by heavy foliage in May; and because the process is slow and tedious, and because it goes on always, everywhere about us, we are apt to count it commonplace. Just as we can understand that the tree in our yard, responding to its environment-to the April showers, to the warm noons of May, to the heat of summer and to the final chill of fall-has completed a transformation in a year, so, too, can we more easily understand the gradual transformation of the cactus in an age. So, too, can we realize that the individual steps between the first ineffectual hairy protuberance, and the final spiny armor, each a stronger attempt to respond to environment, were so gradual as to be almost imperceptible.
But those rudimentary, half formed leaves which come forth from every eye of the cactus slab before the thorns or fruits come out-those leaves which, as if seeing that they have no useful purpose, as if realizing that they are relics, only, of a bygone day, drop off and die-what environment has acted to bring them forth? And those two smooth slabs that push out when the tiny seedling has just poked its thorny head above the ground-to what environment do they respond? How shall we account for this tendency in a plant to jump out of its own surroundings, and out of the surroundings of its parents, and their parents and those before them-and to respond to the influences which surrounded an extinct ancestor-to hark back to the days when the desert was the moist bottom of an evaporating sea and before the animals came to destroy?
A group of scientists were chatting with Luther Burbank when a chance remark on heredity led one of them to tell this bear story. It seemed, so the story ran, that a baby bear had been picked up by miners within a few days after its birth-before its eyes had opened. The cub, in fact, was so small that it was carried several miles to the camp tied in the sleeve of the coat of one of the miners. Raised to adult bearhood by these miners, without ever having seen another bear-relieved of the necessity of finding its own food and removed from the wild environment of its ancestors-this bear became as thoroughly domesticated, almost, as a tabby cat. What would such a bear do if thrown on its own resources? Would it have to begin at the beginning to learn bear-lore? Bears are great salmon fishers, for example. But is this skill taught by the mother to the baby bear-or is it a part of every bear at birth? That was the question of interest. When the animal had arrived at maturity, it was taken, one day, to a shallow salmon stream. Here was a bear which had never fished for salmon, and had never tasted fish; a bear which, if bears have a language, had not received a moment of instruction in self support; a bear which, taken before its eyes were open, had never seen its mother, had never known an influence outside of the artificial atmosphere of the mining camp. Brought to the salmon stream, however, there was not an instant of delay; it glanced about, located a natural point of vantage, straddled the brook with its face down-stream, and bending over, with upraised right paw, waited for the salmon to come. It did, unhesitatingly, just what any normal wild-raised bear would have done. With wonderful dexterity it was able to scoop the onrushing salmon out of the stream and to throw them in an even pile on the bank with a single motion. As other bears would do, this domesticated bruin stood over the stream until it had accumulated a considerable pile of the salmon on the bank. Going to this pile it quickly sorted over the fish, making now two piles instead of one-with all the male salmon in one pile, and all the female salmon in the other. Then, with its sharp claw, it proceeded to split open the female salmon and to extract the roe, which it ate with relish. This consumed, it finished its meal on the other meat of the fish. Untaught, it recognized salmon as food; distinguished males from females; knew the roe as a delicacy. Unpracticed, it knew, instantly, just how to fish for salmon and how to find the roe. "Right here on this experiment farm," spoke up Mr. Burbank, "you might find hundreds of evidences of heredity more striking than that-more striking because they are the evidences of heredity in plant life, instead of in animal life. "Right here," said he, "you will find plants which show tendencies unquestionably inherited from a line of ancestry going back perhaps ten thousand years or more-tendencies, some of them, which now seem strangely out of place because the conditions which gave rise to them in their ancestors no longer exist; tendencies like those of the cactus and the blackberry to protect themselves from wild beasts when wild beasts are no longer enemies; tendencies to deck themselves in colors designed to attract the insects of a forgotten age-insects which, perhaps, no man has ever seen." "Where some incredulity might be expressed as to whether the bear had not actually been taught to fish for salmon, or seen another bear perform the act, there can be no such question in the case of heredity in plants." "Here," said he, as a bed of sweet peas was approached, "is a plant which has inherited the climbing, twining tendency." "That is an evidence that, at some time back in its history, this plant has probably been crowded for room. Plants which grow high do so usually because, at some stage in their existence, they have had to grow high to get the sun and the air which they need. Low-lying plants, like the pumpkin for example, give evidence that they have always enjoyed plenty of space in which to spread out." "The bear of your story may have slipped away, unknown to its keepers, and seen another bear fish for salmon; but if these tendencies and traits, and if the ability to perform the feats necessary for existence are not passed down from mother to son-if they do not come down through the line of ancestry, if all of the old environments of the past have not accumulated into transmissible heredity, what enables that sweet pea to twine around the stake?"
"A closer observation of the sweet pea will show us that its tendrils are really modified leaves, produced, like the spines of the cactus, by ages of environment which, added up, combine to make heredity; and that their actual sensitiveness to touch is so highly developed that they almost instantly encircle and hold fast to any suitable support within their reach." "It would be interesting to take a motion picture of a sweet pea as it grows, as similar motion pictures have been taken; making our separate snapshots one every three minutes instead of fifteen or sixteen to the second, so that the reel would cover a period of fifteen days; then, with a fifteen day history recorded on our film, to run it through the projecting lantern at the rate of fifteen or sixteen pictures to the second, thus showing in seven or eight minutes the motions of growth which actually took fifteen days to accomplish; on the screen before us, with quick, darting motions, we should see the sweet pea wriggle and writhe and squirm-we should see it wave its tendrils around in the air, feeling out every inch within its reach for possible supports on which to twine." "We should see, by condensing half a month of its life into an eight minute reel, that this sweet pea has inherited an actual intelligence-slow in its operation, but positive, certain-an inherited intelligence which would be surprising, even, in an animal."
"All through plant life we find these undeniable evidences of heredity. I have here, for example, two tiny seedlings which look almost alike. They are distantly related. One is the acacia and the other the sensitive plant. Much as these plants look alike, they bear witness to the fact that they have within them two entirely different strains of heredity. The acacia will permit us to touch it and handle it without showing signs of disturbance. But its cousin, in the same soil, and of the same size, immediately folds up its leaves, in self protection, at the slightest touch. From this we read the fact that one branch of this family has found it necessary to perfect a form of self defense, while the other has had no such experience in its life history."
"I have been much interested lately in an experiment with common clover-in producing clover leaves with wonderful markings. The only way in which I can account for the markings with which some clover leaves will bedeck themselves is that, in the heredity of the plant, there was a time when, not being poisonous itself, it tried to simulate the appearance of some poisonous plant, to protect itself from insects. At first thought, it might require a stretch of the imagination to understand how this could be-yet a closer inquiry shows that the process was as gradual and as surely progressive as the transformation of the cactus. In clover, as in other plants, there has always been variation-some few individual clover plants have always had the white and black markings. At some time in the history of the plant those without the markings have been destroyed, and so, responding to this new environment, the markings became more and more pronounced until now we have not only white triangular markings, but ugly black splotches going clear through the leaf. From these markings we can read the history of the clover-most of the family having plain leaves inherited from an ancestry which found no need to protect itself from an enemy-with an occasional outcropping of poisonous-looking color splotches-the inheritance of scattering environments in which self protection was necessary."
"Or we might consider the ice-plant, so called, which protects itself from the heat of the sun by surrounding itself with tiny water drops which have the appearance and serve the same purpose as icicles; or the wild lettuce, known sometimes as the compass plant, which turns its leaves north and south so that only their edges are reached by the sun; or any of a number of other strange protective measures which plants have perfected-all manifestations which would be impossible if heredity were not an ever present, controlling influence. We have, too, in many parts of the country plants which have learned to snare and trap insects and even animals, and to digest them and to live on them. Among these carnivorous plants are the common pitcher plants, and the Venus fly trap. The pitcher plants, instead of belonging only to one family, are to be found in a number of different families, thus showing that environment has produced a similar strain of heredity in separate kinds of plants which are not kin to each other. One of the pitcher plants which grows abundantly in the moist places of the Sierras and in northern California even catches frogs, small animals and birds. The plant seems especially devised to lure the animals into its pitcher. Above the pitcher is a little lattice and an opening, like a window, through which the light can shine. The insects and the animals see a haven from the sun and rain, and as they go in, there are little fingers on the plant which push them along and keep them from coming back. Once securely in the trap, the plant secretes a digestive juice, like our own gastric juice, and absorbs the animal life as food. In these traps it is common to find all kinds of insects-including the undigested wings and legs of beetles and grasshoppers and the bones of toads and frogs. Is this not a more wonderful manifestation of old environment, recorded within a plant in the form of heredity, than even that of a bear which seemed to have inherited the intelligence and skill to fish?"
"To my mind," said one of the scientists, "the by-product of your work is fully as interesting as the work itself-the viewpoint which you get on the forces which control life is of even greater attraction to me than the wonderful productions which you have coaxed from the soil." "A by-product, no," said Mr. Burbank; "these things are a vital part of the day's work. Heredity is more a factor in plant improvement than hoes or rakes; a knowledge of the battle of the tendencies within a plant is the very basis of all plant improvement. It is not, as you seem to think, that the work of plant improvement brings with it, incidentally, a knowledge of those forces. It is the knowledge of those forces, rather, which makes plant improvement possible."
"There are really, after all, only two main influences which enter into the make-up of life-only two influences which we need to direct, in order to change and control the characteristics of any individual growing thing. The first of these is environment. The rains, the snows, the fogs, the droughts-the heat, the cold-the winds, the change in temperature between night and day-the soil, the location in shade or sun-competition for food, light, air-the neighbors, whether they be plant neighbors, or animal neighbors, or human neighbors-all of these, and a thousand other factors which could be thought of, are the elements of environment-some pulling the plant one way and some another, but each with its definite, though sometimes hardly noticeable, influence on the individual plant. And the second is heredity: Which is the sum of all of the environments of a complex ancestry-back to the beginning."
"Just as with the bear, if the story be true, so in plant life. In every seed that is produced there are stored away the tendencies of centuries and centuries of ancestry. The seed is but a bundle of tendencies. When these tendencies have been nicely balanced by a long continuation of unchanging environment, the offspring is likely to resemble the parent. But when, through a change of environment, that balance is disturbed, no man can predict the outcome. So when a seed is planted, no man can be sure whether the twentieth century tendencies will predominate; or whether long-forgotten tendencies may suddenly spring into prominence and carry the plant back to a bygone age."
"How can seeds store up the tendencies of their ancestry?" some one asked Mr. Burbank. "How can your mind store up the impressions which it receives?" he asked in reply.
Hidden away in the twists and turns of our own brains, needing but the right conditions to call them forth with vividness, there are hundreds of thousands, perhaps millions of impressions which have been registered there day by day. The first childhood's scare on learning of the presence of burglars in the house may make us supersensitive to night noises in middle age. The indelible recollection of a mother's love and tenderness may arise, after forty years, to choke down some harsh word which we are about to utter. The combined impressions of a thousand experiences with other human beings seem to blend together to help us form our judgment of a single human being with whom we are about to deal. As the weeks have rolled into months, and as the months have melted into years, new impressions have arisen to crowd out the old; stronger impressions have supplanted the weak, bigger impressions have taken the place of lesser ones-but the old impressions are always there-always blending themselves into our judgments, our ambitions, our desires, our ideals-always ready and waiting, apparently, to single themselves out and appear before us brilliantly whenever the proper combination of conditions arises. So, too, with the seed. Every drought that has caused hardship to its ancestors is recorded as a tendency in that seed. Every favoring condition which has brought a forbear to greater productiveness is there as a tendency in that seed. Every frost, every rain, every rise of the morning sun has left its imprint in the line of ancestry and helped to mold tendencies to be passed from plant to plant. Beneath the wooden looking, hard sheathed covering of the seed, there is confined a bundle of tendencies-an infinite bundle-and nothing more. One tendency stronger than another perhaps--a good tendency suppressing a bad tendency--or the other way; tendencies inherited from immediate parents, tendencies coming down from wild ancestry, tendencies originating from the influences of twenty centuries or more ago-tendencies which are latent, awaiting only the right combination of conditions to bring them to life; all of the tendencies of a complex ancestry-some lulled to sleep, but none obliterated; that is a seed.
"The whole life history of a plant," said Mr. Burbank, "is stored away in its seeds. If we plant enough of the seeds, in enough different environments, we are sure to have that life history with all of its variations, all of its hardships, all of its improvements and retrogressions, uncovered before us."
Which brings us to the boyhood lesson which Luther Burbank learned.
Thomas A. Edison spilled chemicals on the floor of a baggage car-lost his job as train boy-and made electricity his vocation instead of his avocation. Luther Burbank found a seed ball on one of the plants of his mother's potato patch. Who knows what little thing will change a career? Or what accident will transform an ideal? Or what triviality, out of the ordinary, will lead to the discovery of a new truth?
The potato seed ball was a little thing, an accident almost, a triviality, at least, so any practical farmer would have said. Away back in the history of the potato, when it had to depend upon its seed for reproduction, every healthy potato plant bore one or more. But years of cultivation have removed from the potato the necessity of bearing seeds for the preservation of its race. The potato plant, so certain, now, to reproduce itself through subdivision of its bulb or tuber-so reliant on man for its propagation-has little use for the seed upon which its ancestors depended for perpetuation before men relieved it of this burden. So the average potato grower, knowing that next year's crop depends only on this year's tubers--and being more anxious, alas, to keep his crop at a fixed standard than to improve it-might see the occasional seed ball without knowing its meaning-or realizing its possibilities. Luther Burbank saw the seed ball in his mother's potato patch. If he did not realize its possibilities, at least he scented an adventure. And who can say in advance where adventure-any adventure-will lead? How Mr. Burbank lost the precious potato seed ball, how he found it again, and then nearly spoiled the outcome by not knowing how to plant the seed-and the practical lessons in method which he learned-these are things which will be explained at length in the proper place. The interesting fact to be noted here, however, is that, from this seed ball, he produced twenty-three new potato plants. Each of these plants yielded its own interesting individual variations-its own interpretation of long-forgotten heredity. One, a beautiful, long potato, decayed almost as soon as dug; another was red-skinned with white eyes; several had eyes so deep that they were unfit for use; all varied widely. The twenty-three, in fact, represented as many different stages in the history of the potato family; and, having no present-day environment to hold them in balance, all were unlike any potato which had ever been cultivated. Among the number, though, was one tuber better than the rest-and better than any potato which Luther Burbank had ever seen. That tuber was the parent of the almost universally grown Burbank potato of today. When Luther Burbank selected from his twenty-three potato seedlings what eventually was to become the parent of a new race of potatoes, it may be said that he was then fairly started on his successful career of plant improvement. Had he rested on his honors and been satisfied with this single new production, the world would always have been his debtor. For up to that time the potatoes of the world were small, more or less uncertain of bearing, and of mediocre yield. The older varieties-disregarding the fact that their yield was but one-fourth of the present production, would find no buyers in our markets. With the same work-indeed with less-both the pioneer who grew potatoes for his own sustenance and the potato specialist who produced his crop on a commercial basis, were able to quadruple their output-to make four measures of food-four measures of profit-grow where but one had grown before. And today, when more pounds of potatoes are grown than of any other food crop of the world, the increase made in a single year's crop-the increase gained without any corresponding increase in capital invested or cost of production-amounts to an astounding sum in the millions. Possibly at no other time in the history of the nation could the Burbank potato have come more opportunely. These were the days when Chicago was a far western city, and when the great territory beyond was the home of the pioneer. The potato is a vegetable designed peculiarly for the pioneer. It requires no great preparation either for planting or harvesting. It grows rapidly on the rich new soil turned over by the settler; a little cultivation insures its growth; when ripened it may lie in the ground and be used as needed; when the fall frosts come it can easily be banked in a pit for winter use. Little care; small outlay; easy preparation for food; these make the potato the first crop to be grown when the settler locates his new home. Trace now the influence which this one success had upon a growing nation. It was in 1871. It was a time when the line between success and failure-between starvation and comfortable plenty-was drawn so finely for the pioneer that even the slightest help was of a value out of proportion to its intrinsic worth. A crop failure or shortage, in those reconstruction days after the war, meant a set-back that would take years to overcome, for the pioneer's only source of supply, usually, was his own crop. Any increase, therefore, in Nature's products-such as the potato-in the days of the pioneer, signified more to the world than it ever has since. Multiplying a potato yield by four, then, meant more than were such a yield multiplied by ten, or even by a hundred, now.
But the greatest value which the Burbank potato gave to the world was not in the increase in its potato crop; the greatest service it rendered was not even the seventeen-million-dollar-a-year addition to America's farm incomes which this potato has been estimated to have wrought. The greatest value it gave-the greatest service it performed-was to turn Luther Burbank into a new line of invention-into a line in which, because it is so basic and so vast, even a slight improvement means a fortune to the world of consumers-and the perfection of a new food or forage plant untold billions in added wealth.
-Heredity is the sum of all of the environments of a complex ancestry back to the beginning.
This text is from: Luther Burbank: his methods and discoveries and their practical application. Volume 1 Chapter 2