The clear icicle shines in the sun's faint beam, Congealed is the river, the lake, and the stream, The trees are all leafless, while sullen winds roar, And Nature benumbed seems her fate to deplore.
As the weather at this season of the year is generally unfavourable to any employment in the Orchard or Fruit Garden, I cannot occupy a few pages more appropriately than in directing the reader's attention to subjects connected with improvements in the several species and varieties of Fruits; for it must be admitted that there is no kind of fruit, however delicious, that may not be deteriorated, or however worthless, that may not be ameliorated, by particular modes of management; so that after a given variety shall have been created, its merits may be either elicited or destroyed by the cultivator. In this place those practices only need be considered that tend to improvement.
It is an indubitable fact, that all our fruits, without exception, have been so much ameliorated by various circumstances, that they no longer bear any resemblance in respect of quality to their original. Who, for instance, would recognize the wild parent of the Green Gage Plum in the austere Sloe, or that of the delicious Pippin Apples in the worthless acid Crab? Or, what resemblance can be traced between our famous Beurre Pears, whose flesh is so succulent, rich and melting, and that hard, stony, astringent fruit, which even birds and animals refuse to eat? Yet these are undoubted cases of improvement, resulting from time and skill patiently and constantly in action. But it would be of little service to mankind that the quality of any fruit should be improved, unless we adopt some efficient and certain mode of multiplying the individuals when obtained Hence there are two great objects which the cultivator should aim at, viz Amelioration and Propagation.
In planting seed for the purpose of procuring improved varieties, care should be taken not only that the seed be selected from the finest existing kinds, but also that the most handsome, the largest, and the most perfectly ripened specimens should be those that supply the seed. A seedling plant will always partake more or less of the character of its parent, the qualities of which are concentrated in the embryo, when it has arrived at full maturity. As this subject has been already discussed in the second part of this work, page 133, 1 shall direct the reader's attention to the operation of Cross Fertilization.
This is effected by the action of the pollen of one plant upon the stigma of another. The nature of this action is highly curious. Pollen consists of extremely minute hollow balls or bodies; their cavity is filled with fluid, in which swim particles of a figure varying from spherical to oblong, and having an apparently spontaneous motion. The stigma is composed of very lax tissue, the intercellular passages of which have a greater diameter than the moving particles of the pollen. When a grain of pollen comes in contact with the stigma, it bursts, and discharges its contents among the lax tissue upon which it has fallen. The moving particles descend through the tissue of the style, until one, or sometimes more, of them finds its way, by routes especially destined by nature for this service, into a little opening in the integuments of the ovulum or young seed. Once deposited there, the particle swells, increases gradually in size, separates into radicle and cotyledons, and finally becomes the embryo,- the part which is to give birth, when the seed is sown, to a new individual. Such being the mode in which the pollen influences the stigma, and subsequently the seed, a practical consequence of great importance necessarily follows, viz., that in all cases of cross fertilization, the new variety will take chiefly after its polliniferous or male parent; and that at the same time it will acquire some of the constitutional peculiarities of its mother. Thus the male parent of the Downton Strawberry was the Old Black, the female a kind of Scarlet. In Coe's Golden Drop Plum, the father was the Yellow Magnum Bonum, the mother the Green Gage; and in the Elton Cherry, the White Heart was the male parent, and the Graffion the female.
The limits within which experiments of this kind must be confined are, however, narrow. It seems that cross fertilization will not take place at all, or very rarely, between different species, unless these species are nearly related to each other: and that the offspring of two distinct species is itself sterile, or if it possesses the power of multiplying itself by seed, its progeny returns back to the state of one or other of its parents. Hence it seldom or never has happened that domesticated fruits have had such an origin. We have no varieties raised between the Apple and the Pear, or the Plum and Cherry, or the Gooseberry and the Currant. On the other hand, new varieties obtained by the intermixture of two pre-existing varieties are not less prolific, but, on the contrary, often more so than either of their parents: witness the numerous sorts of Flemish Pears which have been raised by cross fertilization from bad bearers, within the last thirty years, and which are the most prolific trees with which gardeners are acquainted; witness also Mr. Knight's Cherries, raised between the May Duke and the Graffion, and the Coe's Plum already mentioned. It is therefore to the intermixture of the most valuable existing varieties of fruit that gardeners should trust for the amelioration of their stock. By this operation the Pears that are in eating in the spring have been rendered as delicious and as fertile as those of the autumn; and there is no apparent reason why those very early, but worthless sorts, such as the Muscat Robert, which usher in the season of Pears, should not be brought to a similar state of perfection.
Lindley recommends the operation of cross fertilization to be performed early in the morning of a dry day; about sun-rise is a good time to begin, and before the blossom is entirely expanded; the pollen being at that time humid, is closely attached to the anthers. The blossoms must be carefully opened and the anthers extracted by delicate scissors, care being taken not to wound the filaments or any other part of the flower. This being done, the matured pollen from another variety must be carefully placed on the blossom which it is intended to fertilize, and from which the anthers have been extracted; and this operation must be repeated twice or three times in the course of the day. By shaking the blossoms over a sheet of white paper, the time when it is perfectly matured will be ascertained. It is necessary to protect the prepared blossom from bees and other insects with thin book - muslin, or gauze, till a swelling is perceived in the germ. When the process has been successful, the pollen which has been placed on the stigma becomes so attached that it cannot be removed with a hair pencil; it changes form and colour, and soon disappears, and the blossom will soon wither and fade; but when the process has been imperfect, the pollen is easily detached from the stigma, its appearance is unaltered, and it remains visible with the duration of the flower, which will continue a long time.
For further information on these subjects, see Outlines of the First Principles of Horticulture, pages 120 to 140 of the second part of this work.