Journal of Agriculture, 1(2): 181-295 (1828)
REMARKS ON A SUPPOSED LAW OF VEGETABLE LIFE, LIMITING THE DURATION OF PLANTS OBTAINED BY CUTTINGS
TO THE NATURAL TERM OF LIFE OF THE STOCK WHENCE THEY WERE TAKEN.
By the Rev. Dr Fleming of Flisk
MANSE OF FLISK, 6th June 1828
IT not unfrequently happens, when a hypothesis is proposed, which in appearance serves to connect a series of imperfectly understood phenomena, that it is embraced rather as an apology for ceasing to investigate, than from a firm conviction of its accordance with truth. When Marshal, in his Rural Economy of Gloucestershire, remarked, that "engrafted fruits are not permanent, they continue but for a time," he probably did not anticipate that he was announcing a conjecture destined to become an article of faith, under different forms, among intelligent agricultural and horticultural writers. Mr. Knight embraced the opinion of Marshal, and, in his Treatise on the Culture of the Apple and Pear, gives it as his opinion, that "the continuance of every variety appears to be confined to a certain period, during the early part of which only it can be propagated with advantage to the planter." Mr Bucknall expresses himself more plainly on the subject, in the Transactions of the Society for the encouragement of Arts. "When the first stock shall, by mere dint of old age, fall into actual decay, a nihility of vegetation, the descendants, however young, or in whatever situation they may be, will gradually decline; and from that time it would become imprudent, in point of profit, to attempt propagating that variety from any of them." There was now only wanting the authority of a botanist, to give sanction to the opinion, that plants obtained by cuttings did not possess an individual vitality, but were merely dependent extensions, sympathising with the frailties of the stock from which they were taken, and incapable of outliving its dissolution. Sir James Edward Smith, the late lamented President of the Linnean Society, considered it as established, that "propagation by seeds is the only true reproduction of plants." With such authorities, this supposed law of vegetable life was eagerly and generally acquiesced in, and considered as accounting for the decay of certain productions of the orchard, the garden, and the fields. Even the humour of Butler had become philosophy, and the cuttings and noses harmonised in expressing similar feelings:
|So learned Taliacotius from
The brawny part of porter's bum
Cut sentimental noses, which
Would last as long as parent breech;
But, when the date of nock was out,
Off dropt the sympathetic snout.
To enter into a detailed refutation of the popular opinion, to which we have now referred, in its different bearings, appears to be unnecessary, as I have elsewhere pointed out its defects.* It may, however, be acceptable to some of your readers, to be put in possession of a few of those facts which demonstrate that this supposed law has been somewhat incautiously admitted by the phytologists of the day.
|*See Philosophy of Zoology, vol. i. p. 426.
†Knight, Phil. Trans. 1816, p. 290.
We are as yet but imperfectly acquainted with the natural term of life of our fruit-trees, which outlive us by many centuries, and cannot, with any degree of propriety, refer the decay of such plants to a cause, which the want of records, and our own limited existence, prevent us from comprehending. But we may adopt the cautious plan of reasoning from what we do know, respecting things analogous, which are yet obscure. There are many herbaceous plants, as the Scarlet Lychnis, the annual stems of which may be converted into extensions, capable of living many years, and giving rise to annual roots and stems like the stock from which it was taken. Cuttings from the Wallflower, a plant limited in its duration to two or three years, may, by cuttings, have existence prolonged; nay, the very branch, which would have flowered and died in the course of a few months, may be made to strike root and flower, year after year, when the stock whence it was taken shall have closed its natural term of life. Even the leaf of a potato may outlive the stem, and be kept alive until the following spring.† Not only may the stems and branches of plants be made to outlive the natural term of life of the stock with which they were connected, but the roots may likewise be made to prolong their functions. Thus I have kept a plant of oats alive for four years, simply by preventing it from producing flowering stems; and the common bean, if subjected to similar treatment, may exhibit a similar longevity. The natural term of life of the osier, in this country certainly very limited, is far exceeded by those extensions, every where propagated for hoops and basket-work. The gooseberry has been considered as subject to this sympathetic law, and many meritorious efforts have been made to raise healthy plants from seed, to supply the place of those destined soon to perish, or which have already exhibited symptoms of decay. But the extent of the useful term of the life of this plant may probably be underrated. In the garden at Pitlithie, in the parish of Leuchars, Fife, the seat of Thomas Lawson, Esq. there is a gooseberry of the ironmonger kind, still in vigour, which was planted in 1760, the fruit on which, two years ago, exceeded twenty Scotch pints.
The potato, it is well known, is subject to disease, in its present condition, by which the success of its cultivation is greatly retarded. It has been asserted that the term of life of the parent stocks having arrived, the extensions can no longer be propagated with advantage; that though a change of soil may for a time retard the tendency to dissolution, renovation can only be effected successfully by raising new plants from seed. It is known to all who have cultivated potatoes to any extent, that a change of seed, from a high, cold and moist district, to a lower, warmer and drier one, is attended with important advantages. The crop is more productive, and the disease termed the Curl in a great measure disappears. But the following fact will demonstrate that the potato may be cultivated long, by extension in the same soil, and without change of seed; and neither disease to any uncommon degree be generated, nor any symptom announcing approaching dissolution.
When, in 1812, I came to reside in the manse here, I was much pleased with the appearance and excellent quality of a large, bent, depressed kidney potato, cultivated by my neighbour, the late Mr. James Sime, tenant in Wester Flisk. He told me, that, thirty years before that period, he brought the seed with him from a farm he previously occupied, about five miles to the eastward; and during the whole intervening period he had annually planted the potatoes in the fields in the immediate neighbourhood, without change. In the spring of 1813, I got a supply for my own use, and from that period to the present I have continued to cultivate the roots, equally without change. In size and quality I have never seen better, nor any equally good. The soil on which this variety of potato has been cultivated, in this immediate neighbourhood, and by extensions from the same stock, during the period of forty-five years, is a stiff clay, with a close tilly bottom, and varying from 150 above, nearly, to the level of the sea, and on the margin of the estuary of the Tay.
Before concluding these hurried observations, I beg distinctly to state, that I by no means deny the existence of those symptoms of decay which certain kinds of fruit-trees or other cultivated vegetables exhibit. I consider it probable that the causes of this decay may yet be traced to the kind of culture, or the constitutional habits of the plants which have been extended. At least, it would be safer to refer such calamities to causes yet to be developed, than to the operation of a law, which does not act where its manifestations ought to be displayed, and where they could be easily detected; but which is supposed to act where its limits are removed from our present powers of investigation, and which will require the lapse of ages before its foundation can be established on the basis of sound induction.