This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
In Mr. W. N. White's interesting report on the grapes of Georgia, I notice the following sentence: "We would not, however, assert that hybridization, naturally or artificially, is absolutely impossible, but nearly so, Ac." So excellent a botanist as Le Conte is also quoted, as doubting the possibility of hybridization ever occurring in the genus Vitis. At first reading, I was rather surprised to find such opinions recorded by such authorities, as hybridization is an everyday occurrence amongst practical grape growers. In early forcing it is often very difficult to get the various kinds of Muscats to set their fruit properly, owing to their stamens proving abortive; this they usually remedy by impregnating the flowers with the pollen of any other grape they may have in bloom at the time, and in that case generally get a pretty full crop of fruit. This, of course, is all that is required to hybridize a grape; and if it were desired to hybridize any variety artificially, all that would be necessary would be to destroy the stamens before the pollen had matured; even though the petals had to be destroyed to get to them, the essential organs of reproduction would not be injured thereby.
The cohering of the petals when they exist are no doubt a bar to natural hybridization; but I have no doubt that the petals are occasionally abortive in a natural state, as I have already stated the stamens are in an artificial.one. Many plants are now known to be polygamous that botanists have been in the habit of considering to bear perfect, flowers in all cases; and as the grape-vine is certainly so at times under artificial treatment, there may be circumstances arise in a natural state sufficient to induce it to change its sexual character there also, and to explain many things which otherwise seem improbable.
It is rather startling, after we have heard so much of the valuable hybrids of Mr. J. F. Allen, of Salem, and others, now to be told that such hybrids are 'impossible.
In another part of the same number of the Horticulturist, another writer recommends to hybridize the native with the foreign grape in order to improve it This is well worth trial, though it may not succeed; for, though there is nothing in the structure of the flower to prevent the attempt, which may not be overcome by artificial means, yet there may be physiological peculiarities which often forbid the intermixture of as closely allied plants as the different species of grapes.