American Pomology. Apples

Alas! for human vanity and apple glory! Where are now these boasted sorts, upon whose merits the immortality of their inventors and first grafters was to depend? They have disappeared from our lists to give place to new favorites, to some of which, perhaps, we are disposed to award an equally high meed of praise, that will again be ignored in a few fleeting years, when higher skill and more scientific applications of knowledge shall have produced superior fruit to any of those we now prize so highly; and this is a consummation to which we may all look forward with pleasure.

In this country the large majority of our favorite fruits, of whatever species or kind, seem to have originated by accident, that is, they have been discovered in seedling orchards, or even in hedge-rows. These have no doubt, however, been produced by accidental crosses of good kinds, and this may occur through the intervention of insects in any orchard of good fruit, where there may chance to be some varieties that have the tendency to progress. The discoveries of Linnæus, and his doctrine of the sexual characters of plants, created quite a revolution in botany, and no doubt attracted the attention of Lord Bacon, who was a close observer of nature, for he ventured to guess that there might be such a thing as crossing the breeds of plants, when he says:—"The compounding or mixture of kinds in plants is not found out, which, nevertheless, if it be possible, is more at command than that of living creatures; wherefore it were one of the most noteable experiments touching plants to find it out, for so you may have great variety of new fruits and flowers yet unknown. Grafting does it not, that mendeth the fruit or doubleth the flowers, etc., but hath not the power to make a new kind, for the scion ever overruleth the stock." In which last observation he shows more knowledge and a deeper insight into the hidden mysteries of plant-life than many a man in our day, whose special business it is to watch, nurse, and care for these humble forms of existence.

Bradley, about a century later, in 1718, is believed to have been the first author who speaks of the accomplishment of cross-breeding, which he describes as having been effected by bringing together the branches of different trees when in blossom. But the gardeners of Holland and the Netherlands were the first to put it into practice.8

The following extract is given to explain the manner in which Mr. Knight conducted his celebrated experiments on fruits, which rewarded him with some varieties that were highly esteemed:—"Many varieties of the apple were collected which had been proved to afford, in mixtures with each other, the finest cider. A tree of each was then obtained by grafting upon a Paradise stock, and these trees were trained to a south wall, or if grafted on Siberian crab, to a west wall, till they afforded blossoms, and the soil in which they were planted was made of the most rich and favorable kind. Each blossom of this species of fruit contains about twenty chives or males (stamens,) and generally five pointals or females (pistils,) which spring from the center of the cup or cavity of the blossom. The males stand in a circle just within the bases of the petals, and are formed of slender threads, each of which terminates in an anther. It is necessary in these experiments that both the fruit and seed should attain as large a size and as much perfection as possible, and therefore a few blossoms only were suffered to remain on each tree. As soon as the blossoms were nearly full-grown, every male in each was carefully extracted, proper care being taken not to injure the pointals; and the blossoms, thus prepared, were closed again, and suffered to remain till they opened spontaneously. The blossoms of the tree which it was proposed to make the male parent of the future variety, were accelerated by being brought into contact with the wall, or retarded by being detached from it, so that they were made to unfold at the required period; and a portion of their pollen, when ready to fall from the mature anthers, was during three or four successive mornings deposited upon the pointals of the blossoms, which consequently afforded seeds. It is necessary in this experiment that one variety of apple only should bear unmutilated blossoms; for, where other varieties are in flower at the same time, the pollen of these will often be conveyed by bees to the prepared blossoms, and the result of the experiment will in consequence be uncertain and unsatisfactory." * * *

In his Pomona Herefordiensis, he says:—"It is necessary to contrive that the two trees from which you intend to raise the new kind, shall blossom at the same time; therefore, if one is an earlier sort than the other, it must be retarded by shading or brought into a cooler situation, and the latest forwarded by a warm wall or a sunny position, so as to procure the desired result."

We must distinguish between hybrids proper and crosses, as it were between races or between what may have been erroneously designated species, for there has been a great deal of looseness in the manner of using these terms by some writers. A true hybrid9 is produced only when the pollen of one species has been used to fertilize the ovules of another, and as a general rule these can only be produced between plants which are very nearly allied, as between species of the same genus. Even such as these, however, cannot always be hybridized, for we have never found a mule or hybrid between the apple and pear, the currant and gooseberry, nor between the raspberry and blackberry, though each of these, respectively, appear to be very nearly related, and they are all of the order Rosaceæ.

In hybrids there appears to be a mixture of the elements of each, and the characters of the mule or cross will depend upon one or the other, which it will more nearly resemble. True hybrids are mules or infertile, and cannot be continued by seed, but must be propagated by cuttings, or layers, or grafting. If not absolutely sterile at first, they become so in the course of the second or third generation. This is proved by several of our flowering plants that have been wonderfully varied by ingenious crossing of different species. But it has been found that the hybrid may be fertilized by pollen taken from one of its parents, and that then the offspring assumes the characters of that parent.10

Natural hybrids do not often occur, though in diœcious plants, this seems to have been the case with willows that present such an intricate puzzle to botanists in their classification, so that it has become almost impossible to say what are the limits and bounds of some of the species. Hybrids are, however, very frequently produced by art, and particularly among our flowering plants, under the hands of ingenious gardeners. Herbert thinks, from his observations, "that the flowers and organs of reproduction partake of the characters of the female parent, while the foliage and habit, or the organs of vegetation, resemble the male."

Simply crossing different members of the same species, like the crossing of races in animal life, is not always easily accomplished; but we here find much less difficulty, and we do not produce a mule progeny. In these experiments the same precautions must be taken to avoid the interference of natural agents in the transportation of pollen from flower to flower; but this process is now so familiar to horticulturists, that it scarcely needs a mention. In our efforts with the strawberry, some very curious results have occurred, and we have learned that some of the recognized species appear under this severe test to be well founded, as the results have been infertile. Where the perfection of the fruit depends upon the development of the seed, this is a very important matter to the fruit-grower; but fortunately this is not always the case, for certain fruits swell and ripen perfectly, though containing not a single well developed seed. It would be an interesting study to trace out those plants which do furnish a well developed fleshy substance or sarcocarp, without the true seeds. Such may be found occasionally in the native persimmon, in certain grapes, and in many apples; but in the strawberry, blackberry, and raspberry, the berry which constitutes our desirable fruit, never swells unless the germs have been impregnated and the seeds perfect. In the stone-fruits the stone or pit is always developed, but the enclosed seed is often imperfect from want of impregnation or other cause—and yet the fleshy covering will sometimes swell and ripen.

One of the most successful experimenters in this country is Doctor J.P. Kirtland, near Cleveland, Ohio, whose efforts at crossing certain favorite cherries, were crowned with the most happy results, and all are familiar with the fruits that have been derived from his crosses. The details of his applying the pollen of one flower to the pistils of another are familiar to all intelligent readers, and have been so often set forth, that they need not be repeated in this case—great care is necessary to secure the desired object, and to guard against interference from causes that would endanger or impair the value of the results.

Van Mons' theory was based upon certain assumptions and observations, some of which are well founded, others are not so firmly established. He claimed correctly that all our best fruits were artificial products, because the essential elements for the preservation of the species in their natural condition, are vigor of the plant and perfect seeds for the perpetuation of the race. It has been the object of culture to diminish the extreme vigor of the tree so as to produce early fruitage, and at the same time to enlarge and to refine the pulpy portion of the fruit. He claimed, as a principle, that our plants of culture had always a tendency to run back toward the original or wild type, when they were grown from seeds. This tendency is admitted to exist in many cases, but it is also claimed, that when a break is once made from the normal type, the tendency to improve may be established. Van Mons asserted that the seeds from old trees would be still more apt to run back toward the original type, and that "the older the tree, the nearer will the seedlings raised from it approach the wild state," though he says they will not quite reach it. But the seeds from a young tree, having itself the tendency to melioration, are more likely to produce improved sorts.

He thinks there is a limit to perfection, and that, when this is reached, the next generation will more probably produce bad fruit than those grown from an inferior sort, which is on the upward road of progression. He claims that the seeds of the oldest varieties of good fruit yield inferior kinds, whereas those taken from new varieties of bad fruit, and reproduced for several generations, will certainly give satisfactory results in good fruit.

He began with seeds from a young seedling tree, not grafted upon another stock; he cared nothing for the quality of the fruit, but preferred that the variety was showing a tendency to improvement or variation. These were sowed, and from the plants produced, he selected such as appeared to him to have evidence of improvement, (it is supposed by their less wild appearance), and transplanted them to stations where they could develop themselves. When they fruited, even if indifferent, if they continued to give evidence of variation, the first seeds were saved and planted and treated in the same way. These came earlier into fruit than the first, and showed a greater promise. Successive generations were thus produced to the fourth and fifth, each came into bearing earlier than its predecessor, and produced a greater number of good varieties, and he says that in the fifth generation they were nearly all of great excellence. He found pears required the longest time, five generations; while the apple was perfected in four, and stone fruits in three.

Starting upon the theory that we must subdue the vigor of the wilding to produce the best fruits, he cut off the tap roots when transplanting and shortened the leaders, and crowded the plants in the orchard or fruiting grounds, so as to stand but a few feet apart. He urged the "regenerating in a direct line of descent as rapidly as possible an improving variety, taking care that there be no interval between the generations. To sow, re-sow, to sow again, to sow perpetually, in short to do nothing but sow, is the practice to be pursued, and which cannot be departed from; and, in short, this is the whole secret of the art I have employed." (Arbres Fruitiers.)

Who else would have the needed patience and perseverance to pursue such a course? Very few, indeed—especially if they were not very fully convinced of the correctness of the premises upon which this theory is founded. Mr. Downing thinks that the great numbers of fine varieties of apples that have been produced in this country, go to sustain the Van Mons doctrine, because, as he assumes, the first apples that were produced from seeds brought over by the early emigrants, yielded inferior fruit which had run back toward the wild state, and the people were forced to begin again with them, and that they most naturally pursued this very plan, taking seeds from the improving varieties for the next generations and so on. This may have been so, but it is mere assumption—we have no proof, and, on the contrary, our choice varieties have so generally been conceded to have been chance seedlings, that there appears little evidence to support it—on the contrary, some very fine varieties have been produced by selecting the seeds of good sorts promiscuously, and without regarding the age of the trees from which the fruit was taken. Mr. Downing himself, after telling us that we have much encouragement to experiment upon this plan of perfecting fruits, by taking seeds from such as are not quite ripe, gathered from a seedling of promising quality, from a healthy young tree (quite young,) on its own root, not grafted, and that we "must avoid 1st, the seeds of old trees; 2d, those of grafted trees; 3d, that we must have the best grounds for good results"—still admits what we all know, that "in this country, new varieties of rare excellence are sometimes obtained at once by planting the seeds of old grafted varieties; thus the Lawrence Favorite and the Columbia Plums were raised from seeds of the Green Gage, one of the oldest European varieties."

Let us now look at an absolute experiment conducted avowedly upon the Van Mons plan in our own country, upon the fertile soil of the State of Illinois, and see to what results it led:—

The following facts have been elicited from correspondence with H.P. Brayshaw, of Du Quoin, Illinois. The experiments were instituted by his father many years ago, to test the truth of the Van Mons' theory of the improvement of fruits by using only the first seeds.

Thirty-five years ago, in 1827, his father procured twenty-five seedling trees from a nursery, which may be supposed to have been an average lot, grown from promiscuous seed. These were planted, and when they came into bearing, six of them furnished fruit that might be called "good" and of these, "four were considered fine." One of the six is still in cultivation, and known as the Illinois Greening. Of the remainder of the trees, some of the fruits were fair, and the rest were worthless, and have disappeared.

Second Generation.—The first fruits of these trees were selected, and the seeds were sown. Of the resulting crop, some furnished fruit that was "good," but they do not appear to have merited much attention.

Third Generation.—From first seeds of the above, one hundred trees were produced, some of which were good fruit, and some "even fine," while some were very poor, "four or five only merited attention." So that we see a retrogression from the random seedlings, furnishing twenty-five per cent, of good fruit, to only four or five per cent. in the third generation, that were worthy of note.

Fourth Generation.—A crop of the first seed was again sown, producing a fourth generation; of these many were "good culinary fruits," none, or very few being of the "poorest class of seedlings," none of them, however, were fine enough "for the dessert."

Fifth Generation.—This crop of seedlings was destroyed by the cut-worms, so that only one tree now remains, but has not yet fruited. But Mr. Brayshaw appears to feel hopeful of the results, and promises to continue the experiment.

Crops have also been sown from some of these trees, but a smaller proportion of the seedlings thus produced were good fruits, than when the first seeds were used—this Mr. Brayshaw considers confirmatory evidence of the theory, though he appears to feel confidence in the varieties already in use, most of which had almost an accidental origin.

He thinks the result would have been more successful had the blossoms been protected from impregnation by other trees, and recommends that those to be experimented with should be planted at a distance from orchards, so as to avoid this cross-breeding, and to allow of what is called breeding in-and-in. If this were done, he feels confident that "the seedlings would more nearly resemble the parent, and to a certain extent would manifest the tendency to improvement, and that from the earliest ripened fruits, some earlier varieties would be produced, from those latest ripening, later varieties, from those that were inferior and insipid, poor sorts would spring, and that from the very best and most perfect fruits we might expect one in one thousand, or one-tenth of one per cent., to be better than the parent." This diminishes the chance for improvement to a beautifully fine point upon which to hang our hopes of the result of many generations of seedlings occupying more than a lifetime of experiments.

Mr. Brayshaw, citing some of the generally adopted axioms of breeders of animals, assumes that crosses, as of distinct races, will not be so likely to produce good results, as a system of breeding in-and-in, persistently carried out. This plan he recommends, and alludes to the quince and mulberry as suitable species to operate upon, because in them there are fewer varieties, and therefore less liability to cross-breeding, and a better opportunity for breeding in-and-in. He also reminds us of the happy results which follow the careful selection of the best specimens in garden flowers and vegetables, combined with the rejection of all inferior plants, when we desire to improve the character of our garden products, and he adopts the views of certain physiologists, which, however, are questioned by other authorities, to the effect that violent or decided crosses are always followed by depreciation and deterioration of the offspring.

The whole communication referring to these experiments, which are almost the only ones, so far as I know, which have been conducted in this country to any extent, to verify or controvert the Van Mons' theory, is very interesting, but it is easy to perceive that the experimenter, though apparently very fair, and entirely honest, has been fully imbued with the truth and correctness of the proposition of Van Mons, that the first ripened seed of a natural plant was more likely to produce an improved variety, and that this tendency to improvement would ever increase, and be most prominent in the first ripened seeds of successive generations grown from it.

The theory of Van Mons I shall not attempt in this place to controvert, but will simply say that nothing which has yet come under my observation has had a tendency to make me a convert to the avowed views of that great Belgian Pomologist, while, on the contrary, the rumors of his opponents, that he was really attempting to produce crosses from some of the best fruits, as our gardeners have most successfully done in numerous instances, in the beautiful flowers and delicious vegetables of modern horticulture, have always impressed me with a color of probability, and if he were not actually and intentionally impregnating the blossoms with pollen of the better varieties, natural causes, such as the moving currents of air, and the ever active insects, whose special function in many instances appears to be the conveyance of pollen, would necessarily cause an admixture, which, in a promiscuous and crowded collection, like the "school of Van Mons," would at least have an equal chance of producing an improvement in some of the resulting seeds.

The whole subject of variation in species, the existence of varieties, and also of those partial sports, which may perhaps be considered as still more temporary variations from the originals, than those which come through the seeds, is one of deep interest, well worthy of our study, but concerning which we must confess ourselves as yet quite ignorant, and our best botanists do not agree even as to the specific distinctions that have been set up as characters of some of our familiar plants, for the most eminent differ with regard to the species of some of our common trees and plants.