The peaches of New York

by U. P. Hedrick

HAS THE PEACH COME FROM THE ALMOND?

In the light of evolution every plant has been preceded by another and since the peach and almond have many characters in common, one may have descended from the other. But as to which, if either, is the parent species it would seem idle to speculate with the shreddy and patchy knowledge we now possess of the descent of plants. Yet Thomas Andrew Knight, the greatest horticultural authority of his time and one of the leading experimenters of all time in this field of agriculture, maintained that the peach is a modified almond. His theory received the support of several of the leading English horticulturists of the last century and Darwin gave it credence to the extent of collecting data for its substantiation.

Knight believed that the almond and the peach constituted a single species and that by selection under cultivation an almond could ultimately be turned into a peach.[10] He sought proof for his theory in hybridization and on a tree raised from the seed of an almond fertilized by peach-pollen produced a fruit with soft and melting flesh and in all characteristics more like the peach than the almond. This experiment, which in the light of our present knowledge of the laws of inheritance does not in the least illuminate the hypothesis with which Knight started, carried on in the medieval days of plant-breeding, convinced not only Knight in his belief that the peach may be bred from the almond but led others, even down to our own time, to accept the theory.

Thus, a writer, presumably Lindley, in The Gardener's Chronicle[11] in 1856 says "we are justified in the conclusion that the Almond bears about the same relation to the Peach that the Crab bears to the Cultivated Apple." Later, in the same article, the descent is pictured as follows:

"1.	Almond became more fleshy—Bad clingstone.
2.	Bad clingstone became more fleshy—Good clingstone.
3.	Good clingstone became more fleshy—Our soft peaches.
4.	Soft peach sported, receding toward the original fleshy type and lost its wool—Nectarine."

Another high authority in his time, Thomas Rivers,[12] in 1863, held that peaches, if left to a state of nature would degenerate into thick-fleshed almonds and makes the positive statement that he has "one or two seedling peaches approaching very nearly to that state."

Darwin,[13] in 1868, considers Knight's supposition at length and while he does not positively accept it, yet lends it his support by quoting several authors who put forth proofs in favor of it. His most positive statement in discussing the theory referring to facts regarding the origin of the peach is: "The supposition, however, that the peach is a modified almond which acquired its present character at a comparatively late period, would, I presume, account for these facts."

Carrière,[14] one of the most eminent French pomologists of the last century, is the chief French champion of the theory that the peach came from the almond and devotes several pages in his estimable work, Variétés De Pêchers, in demonstrating that the one is a form of the other. His arguments, however, are but amplifications of those of Knight and Lindley though he cites more intermediate forms than either of the English writers—so many that they go far toward convincing one of the correctness of his views. There is the feeling, however, in the case of Carrière, in the light of present knowledge, that his botanical evidence is pushed a little too far for full credulity.

Knight, Lindley, Rivers, Darwin and Carrière, the men holding the theory whose opinions are most worthy consideration, fell into error, as we think, through attaching too much importance to likenesses in the fruits of the peach and almond and because they became confused in following the behavior of the two fruits under hybridization. As we shall show later in discussing the characters of the peach, this fruit differs from the almond in other characters than those of the fruit—characters not at all likely to be changed by cultivation and selection as would all those of the fruits. Knight's proof from hybridization was purely speculative. The fact that the peach and almond may be crossed, giving intermediate forms, nowadays would not be looked upon as proof that the two necessarily belong to one species. However, in the light of the knowledge in existence at the beginning of the last century regarding the crossing of plants, we need not apologize for the inference that Knight drew from his simple experiment.

Students of heredity would find almost conclusive proof that the peach is not a modified almond—a descendant, say, in this geologic period at least—in the fact that there is no recorded case of a peach fertilized by a peach producing an almond, or vice versa. If the relationship were at all close, if the two species had had a common origin even though in rather remote times, if they were nearly enough related readily to hybridize or be hybridized, it would be expected that now and then, as in the case of a nectarine, the peach would produce an almond or the almond a peach.

Geographical botany also opposes Knight's hypothesis, as De Candolle[15] points out, for, as he plainly shows, the almond had its origin in western Asia, it being found truly wild in many parts of south-western Asia and having been cultivated many centuries before the peach was known in these regions. On the other hand, the almond was not known in China before the Christian era whereas the peach had been cultivated there at least 2000 years anterior to the introduction of the almond. With such widely separated habitats, the two fruits can hardly be considered as parent and offspring.

We cannot close our eyes to the patent relationships of the peach and the almond. That the two constitute but one species, as we now consider species, or that they bear the close relationship of the peach and the nectarine, probably no one now in high authority will concede. But for the weight of the names we have used, and the fact that the theory still finds supporters, Knight's hypothesis, the outcropping of a speculative mind in a speculative age, might have been overlooked or dismissed with a word.