The Fruits and Fruit Trees of America p. 5 (1845)

Andrew Jackson Downing

Now many of the varieties of fruit trees have a similar power of intermixing with each other while in blossom, by the dust or pollen of their flowers, carried through the air, by the action of bees and other causes. It will readily occur to the reader, in considering this fact, what an influence our custom of planting the different varieties of plum or of cherry together in a garden or orchard, must have upon the constancy of habit in the seedlings of such fruits.

But there is still another reason for this habit, so perplexing to the novice, who, having tasted a luscious fruit, plants, watches and rears its seedling, to find it perhaps, wholly different in most respects. This is the influence of grafting. Among the great number of seedling fruits produced in the United States, there is found occasionally a variety, perhaps a plum or a peach, which will nearly always reproduce itself from seed. From some fortunate circumstances in its origin, unknown to us, this sort, in becoming improved, still retains strongly this habit of the natural or wild form, and its seeds produce the same. We can call to mind several examples of this; fine fruit trees whose seeds have established the reputation in their neighborhood of fidelity to the sort. But when a graft is taken from one of these trees, and placed upon another stock, this grafted tree is found to lose its singular power of producing the same by seed, and becomes like all other worked trees. The stock exercises some, as yet, unexplained power, in dissolving the strong natural habit of the variety, and it becomes like its fellows, subject to the laws of its artificial life.

When we desire to raise new varieties of fruit, the common practice is to collect the seeds of the finest table fruits—those sorts whose merits are every where acknowledged to be the highest. In proceeding thus we are all pretty well aware, that the chances are generally a hundred to one against our obtaining any new variety of great excellence. Before we offer any advice on rearing seedlings let us examine briefly the practice and views of two distinguished horticulturists abroad, who have paid more attention to this subject than any other persons whatever; Dr. Van Mons of Belgium, and Thos. Andrew Knight, Esq., the late President of the Horticultural Society of London.

Darwin: An. and Pl. 2, ch. 22, pp. 246-247

Some facts on the effects of grafting, in regard to the variability of trees, deserve attention. Cabanis asserts that when certain pears are grafted on the quince, their seeds yield a greater number of varieties than do the seeds of the same variety of pear when grafted on the wild pear.14 But as the pear and quince are distinct species, though so closely related that the one can be readily grafted and succeeds admirably on the other, the fact of variability being thus caused is not surprising; as we are here enabled to see the cause, namely, the very different nature of the stock and graft. Several North American varieties of the plum and peach are well known to reproduce themselves truly by seed; but Downing asserts,15 "that when a graft is taken from one of these trees and placed upon another stock, this grafted tree is found to lose its singular property of producing the same variety by seed, and becomes like all other worked trees;"—that is, its seedlings become highly variable. Another case is worth giving: the Lalande variety of the walnut-tree leafs between April 20th and May 15th, and its seedlings invariably inherit the same habit; whilst several other varieties of the walnut leaf in June. Now, if seedlings are raised from the May-leafing Lalande variety, grafted on another May-leafing variety, though both stock and graft have the same early habit of leafing, yet the seedlings leaf at various times, even as late as the 5th of June.16 Such facts as these are well fitted to show on what obscure and slight causes variability depends.

14. Quoted by Sageret, 'Pom. Phys.,' 1830, p. 43. This statement, however, is not believed by Decaisne.
15. 'The Fruits of America,' 1845,
16. M. Cardan, in 'Comptes Rendus,' Dec. 1848, quoted in 'Gard. Chronicle,' 1849, p. 101.