Peter Collinson in 1741 recorded the first case of a peach-tree producing a nectarine (10/42. 'Correspondence of Linnaeus' 1821 pages 7, 8, 70.) and in 1766 he added two other instances. In the same work, the editor, Sir J.E. Smith, describes the more remarkable case of a tree in Norfolk which usually bore both perfect nectarines and perfect peaches; but during two seasons some of the fruit were half and half in nature.
Mr. Salisbury in 1808 (10/43. 'Transact. Hort. Soc.' volume 1 page 103.) records six other cases of peach-trees producing nectarines. Three of the varieties are named; viz., the Alberge, Belle Chevreuse, and Royal George. This latter tree seldom failed to produce both kinds of fruit. He gives another case of a half-and-half fruit.
At Radford in Devonshire (10/44. Loudon's 'Gardener's Mag.' 1826 volume 1. page 471.) a clingstone peach, purchased as the Chancellor, was planted in 1815, and in 1824, after having previously produced peaches alone, bore on one branch twelve nectarines; in 1825 the same branch yielded twenty-six nectarines, and in 1826 thirty-six nectarines, together with eighteen peaches. One of the peaches was almost as smooth on one side as a nectarine. The nectarines were as dark as, but smaller than, the Elruge.
At Beccles a Royal George peach (10/45. Loudon's 'Gardener's Mag.' 1828 page 53.) produced a fruit, "three parts of it being peach and one part nectarine, quite distinct in appearance as well as in flavour." The lines of division were longitudinal, as represented in the woodcut. A nectarine- tree grew five yards from this tree.
Professor Chapman states (10/46. Ibid 1830 page 597.) that he has often seen in Virginia very old peach-trees bearing nectarines.
A writer in the 'Gardener's Chronicle' says that a peach tree planted fifteen years previously (10/47. 'Gardener's Chronicle' 1841 page 617.) produced this year a nectarine between two peaches; a nectarine-tree grew close by.
In 1844 (10/48. 'Gardener's Chronicle' 1844 page 589.) a Vanguard peach- tree produced, in the midst of its ordinary fruit, a single red Roman nectarine.
Mr. Calver is stated (10/49. 'Phytologist' volume 4 page 299.) to have raised in the United States a seedling peach which produced a mixed crop of both peaches and nectarines.
Near Dorking (10/50. 'Gardener's Chronicle' 1856 page 531.) a branch of the Teton de Venus peach, which reproduces itself truly by seed (10/51. Godron, 'De l'Espece' tome 2 page 97.), bore its own fruit "so remarkable for its prominent point, and a nectarine rather smaller but well formed and quite round."
The previous cases all refer to peaches suddenly producing nectarines, but at Carclew (10/52. 'Gardener's Chronicle' 1856 page 531.) the unique case occurred, of a nectarine-tree, raised twenty years before from seed and never grafted, producing a fruit half peach and half nectarine; subsequently bore a perfect peach.
To sum up the foregoing facts; we have excellent evidence of peach-stones producing nectarine-trees, and of nectarine-stones producing peach-trees,-- of the same tree bearing peaches and nectarines,--of peach-trees suddenly producing by bud-variation nectarines (such nectarines reproducing nectarines by seed), as well as fruit in part nectarine and in part peach,- -and, lastly, of one nectarine-tree first bearing half-and-half fruit, and subsequently true peaches. As the peach came into existence before the nectarine, it might have been expected from the law of reversion that nectarines would have given birth by bud-variation or by seed to peaches, oftener than peaches to nectarines; but this is by no means the case.
Two explanations have been suggested to account for these conversions. First, that the parent trees have been in every case hybrids (10/53. Alph. De Candolle 'Geograph. Bot.' page 886.) between the peach and nectarine, and have reverted by bud-variation or by seed to one of their pure parent forms. This view in itself is not very improbable; for the Mountaineer peach, which was raised by Knight from the red nutmeg-peach by pollen of the violette hative nectarine (10/54.