In his introductory remarks relative to the objects which the Horticultural Society have in view. (Transactions of the Horticultural Society of London 1: 1-7, 1820), Thomas Andrew Knight formulated the state of art and also the future goal of the incipient society. Several statements of Knight are relevant to later (much later) claims that Darwin plagiarized others. For some reason Knight has never been implicated as s source being plagiarized nor has Knight (ASAIK) ever alleged such plagiraism on Darwin's part.
Thomas Andrew Knight(1820). Introductory Remarks relative to the objects which the Horticultural Society have in view: Transactions of the Horticultural Society of London 1: 1-7.
"We, however, know that flowers and fruits are the necessary produce of improved culture; and that the offspring, in a greater or less degree, inherits the character of its parents. The austere Crab of our woods has thus been converted into the Golden Pippin; and the numerous varieties of the Plum, can boast no other parent than our Sloe."
Why do I quote this? Because Mike Sutton claims that Darwin has, by writing about the Golden Pippin, incriminated himself of plagiarizing Matthew (1831. On naval Timber and Arboriculture), when the crab apple and the Golden Pippin were standard items of research.
"Experience and observation appear to have sufficiently proved, that all plants have a natural tendency to adapt their habits to every climate in which art or accident places them: and thus the Pear-tree, which appears to be a native of the southern part of Europe, or the adjoining parts of Asia, has completely naturalized itself in Britain, and has acquired, in a great number of instances, the power to ripen its fruit in the early part even of an unfavourable summer: the Crab tree has in the same manner adapted its habits to the frozen regions of Siberia. But when we impart either of these fruits, in their cultivated state, from happier climates, they are often found incapable of acquiring a perfect state of maturity even when trained to a south wall."
"Almost every plant, the existence of which is not confined to a single summer, admits of two modes of propagation; by division of its parts, and by seed. By the first of these methods we are enabled to multiply an individual into many; each of which, in its leaves, its flowers, and fruit, permanently retains, in every respects, the character of the parent stock. No new life is here generated;and the graft, the layer, and cutting, appear to possess the youth and vigour, or the age and debility, of the plant, of which they once formed part.* No permanent improvement has therefore ever been derived, or can be expected, from the art of the grafter, or the choice of stocks of different species, or varieties: for, to use the phrase of LORD BACON, the graft in all cases overruleth the stock, from which it receives ailment, but no motion. Seedling plants, on the contrary, of every cultivated species, sport in endless variety. By selection from these, therefore, we can only hope for success in our pursuit of new and improved varieties of each species of plant or fruit; and to promote experiments of this kind...
* The diseased state of the young grafted trees of the Golden Pippin, and the debasement of the flavour of that fruit, afford one, amongst the thousand instances, which have been long propagated by grafting, &c."
Why do I quote this? Because it amounts to yet another premonition of natural selection as a force leading to change within species.
"... but trees, being formed for periods of longer duration, are frequently much injured by the injudicious and excessive use of manure."
Why do I quote this? Because it shows that Matthew's ideas about manure are not original either.