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.
It has long been known, says D'Albert, that, in order to preserve grafts, especially for transportation, they ought to be separated from the parent tree before they have begun to grow. They ought then to be placed in a northern exposure, in a horizontal position, on the ground, and covered with earth to about the depth of two inches and a half. They should remain in that position till their buds are well swelled, by which time the stock intended for their reception will be much more advanced, a necessary condition to success. Under all circumstances, they mast be so packed as to run no risk of heating. French gardeners often place them in the hollow of an old cucumber, and even pack them in honey, without injury, if they have a long distance to travel; if they are to be conveyed to a distance, it is best to send them off as soon as they are taken from the tree. If the journey require only three weeks or a month, it is sufficient to tie them up in packets, putting some dry moss between them, in order to prevent their being bruised, and to insert their bases in a ball of moist clay, covered with fresh moss, the whole tightly enveloped in a thin coating of straw.
But if the cuttings have to be sent a great distance, so as to be months on the way, they should be inclosed in a box, in small parcels, all laid with their tops in the same direction, their thick ends covered with clay and fresh moss, the whole compactly fastened with laths likewise coated with moss. If for a long sea-voyage, care should be taken to close the box, some holes being made in the top, to prevent the shoots becoming mouldy. This is excellent advice.
Dr. Lindley adds, that so long as it was believed that absolute wood was formed corporeally from above downwards, it was inferred that the lower parts of a plant must be gradually encased in solid matter derived from branches, and that, consequently, of necessity, the stock of a plant must be enveloped in layer above layer of the scion. It is needless to repeat the arguments employed in support of this view; they were cogent, and, for a long time, held to be irrefragable. The application of the theory to grafting, led, among other things, to the conclusion, that a scion would speedily form a sheath of wood over the stock, and thus secure itself forever. Once to form a good union, was therefore looked upon as sufficient-security for the permanent life of the grafted plant. Cases, apparently at variance with the theory, occurred now and then, but plausible explanations of such instances were readily found.
It is, however, now certain, continues the Doctor, that although wood is formed by a descending process, yet that its descent is not in an organized state. Fluid matter, out of which it is produced, passes, indeed, from above downwards, but the formation itself is wholly local and superficial, and consequently, there is no such thing as an encasement of the lower part of a tree by wood descending from above. That important fact having been once established, the union of a scion and its stock evidently becomes a case of mere adhesion, extremely powerful in some cases, feeble and readily destroyed in others. There are, therefore, two essentially different results obtained by grafting - the one permanent, the other transitory. The accompanying example affords a new demonstration that the union between a scion and its stock is no other than that now described. About the beginning of September, 1853, Dr. Maclean, of Colchester, an ingenious experimentalist and good physiologist, grafted a young plant of the White Silesian Beet upon a root of Red Beet, and vice versa. At the time of the experiment, the plants were each about as thick as a straw.
A complete junction was effected, and when, in 1854, the White Beet grafted on Red was taken out of the ground, its longitudinal section exhibited the appearance represented in the figure. There was a slight contraction at the line of junction; above the line of contraction, the plant was absolutely white, below it was absolutely red. Not a trace of blending of the two colors could be discovered. By similar experiments on other vegetables and plants, Dr. Maclean had so far assured himself of the perfect independence of scion and stock as to acquire the belief that neither the coloring nor any of the specific characters of the one or the other, would or could be altered by their union. The result of the trial wholly confirmed that view, and demonstrated that the White Beet adhered to the Red Beet by mere junction of cellular matter, that of the scion and stock holding together in the first instance, and each afterwards producing its own coloring matter in its, own new cells, as they formed superficially, the red cells adhering to the white cells while in the nascent state, but retaining each the peculiarity belonging to it, without any interchange of contents through the sides of the cells in contact.
This is entirely consistent with all that has been discovered by the modern physiologists who have applied themselves to a study of the nature of the individual cells of which plants consist. They have clearly shown that each cell has its own inherent power of secretion, as, indeed, may be seen by any one who examines thin sections of variegated leaves, or other parts. It will then be found that some cells are filled with a red coloring matter, some with yellow, 6ome with green. In other words, one cell has the power of secreting red matter, another yellow, and so on. The colors do not run together, but are contained each within the cell that produces it Why this is so, no one knows; all that we are acquainted with is the fact; the peculiar cells are not affected by the one growing on the other. Red-forming cells produce their like, and yellow-forming theirs. Thus the limit between the scion and its stock is unmistakably traceable, and, notwithstanding the combination of the two sorts in one, each perseveringly retains that which is natural to it.
It hence becomes evident that no junction can be permanent unless the stock and scion have a great similarity, not only in every part of their structure, but also in constitution, and that the strictest consanguinity alone offers security that a grafted plant shall be as durable as each of the two individuals thus artificially joined is, when left on its own roots. A temporary union may indeed be effected, but it is soon dissolved, as we everywhere see, in collections where grafted varieties are brought together, instead of plants "on their own bottom," We have used D'Albert's and Dr. Lindley's own words above; they are convincing, and the intelligent fruit grower cannot fail to take advantage of them.
Editor of the Horticulturist - Dear Sir: A paper headed as above, in the December No., has very much interested me, as it confirms me in the same idea which I have held for some time. I must tell you that I am one of those who care little to know how any operation in this business is performed, unless they can at the same time be permitted to know the reason why. Believing that there are many such among your readers, I make no apology for endeavoring to keep the subject before them.
That each cell must have its own inherent power of secretion, has often struck me. I once saw a white Muscat of Alexandria grape, grafted on the end of a cane of the black Hamburg. It of course always bore white Muscat grapes, in every shade of color, every form, and every peculiarity of taste the same as other Muscats not grafted; yet all its sap had to be drawn through the cells or sap vessels of the Hamburg. If the first had the power of forming its own peculiar secretions so as to retain its exact distinctiveness, why should the wood-producing principle be deemed an exception?
If wood was formed, corporeally, from above downwards, would it not in time so encase the wood of the stock, that when a shoot sprung out of what was once the stock, it would be of the same character as the scion? For I have never understood that physiologists believe that the bud or eye producing shoot, proceeds, in all cases, through from the pith, as the heart or pith of trees is often dead and rotten many years before the outsides begin to decay.
Satisfied that the true theory of grafting is now settled, I give the following chip for what it is worth, in return for the information I have received: -
Two years ago I received a lot of pear grafts from a distant friend. They were buried in the ground at the ends, so as to preserve them a few weeks till the season was further advanced. When that came, the closest search could not find them. In July, while budding pears, I "ran against" these grafts. They appeared green and tolerably fresh, so I budded them, as I would do with young wood. Every bud had started to grow immediately, and made, on an average, shoots a foot long before fall. The result was that, though I had not quite as strong plants as I should have had by March grafting, I had double the quantity I should have had, besides no failures. I think my practical friends may probably turn this fact to some account.
While on the subject, I would like to inquire on what theory root-grafting apples is supposed to render them less hardy or vigorous, as I see Mr. Hovey and others hold. I have compared seedling Kentucky coffee's, ailanthus' and Paul-ownias, with others raised from pieces of roots, and can trace no difference in their relative vigor or hardiness; nor can I see any difference in the vigor or hardiness of a root-grafted rose over one grafted in any other way. But even could I see any difference, I should not rest satisfied with the impression that " I could attribute it to nothing else," unless I could see some trace of a physiological reason why it should be so, which I confess I cannot do. I should be glad if some of our friends who hold Mr. Hovey's view would enlighten us.