Its germinating power

Field, Forest and Farm by Jean-Henri Fabre, is part of the HackerNoon Books Series. You can jump to any chapter in this book here. GERMINATION

CHAPTER XXIX. GERMINATION

“The germ in the heart of the seed is in a state that may be likened to deep sleep: its life is, as it were, arrested, suspended. But under the stimulus of certain conditions it awakens, throws off its coverings, gathers strength from its stored-up food, unfolds its first leaves, and appears above ground. This opening of the seed is called germination. Moisture, warmth, and air are the determining causes; without their coöperation the seed would remain a certain length of time in good condition for sowing, after which it would wither and lose its germinating power.

“No seed germinates without the help of moisture. Water plays a multiple part. First it soaks into the germ and the parts surrounding it, causing these to swell more than the envelope, so that the latter, however hard a shell it may be, is burst open. Through the cracks of this broken envelope the gemmule pushes out on one side and the radicle on the other, and henceforth the little plant enjoys the benefit of sun and air. Germination is more or less slow according to the degree of resistance offered by the walls of the seed. If these are hard and stony it is only with extreme slowness that the germ absorbs [139]moisture and manages to burst its cell. Therefore, to shorten the period of germination care is taken to thin the shells of excessively hard seeds by rubbing them with a stone.

“Besides the mechanical part played by water in opening the seed, it has still another relating to nutrition. The various changes undergone by the alimentary contents of the perisperm and the cotyledons in becoming liquefied and capable of absorption cannot take place without the aid of water. Furthermore, this liquid is indispensable for dissolving the nutritive ingredients, introducing them into the young plant, and distributing them evenly throughout. It is plain, then, that if the seed remains dry it is absolutely impossible for it to germinate, and that in order to preserve seeds the first condition is to protect them from moisture.

“With moisture there must also be warmth. As a general rule, germination proceeds most satisfactorily when the thermometer registers between ten and twenty degrees centigrade, our spring and autumn temperature. Outside these limits, be it above or below, germination is retarded, ceasing altogether in extreme temperatures.

“The coöperation of air is not less necessary. Seeds might have the proper temperature and sufficient moisture, but if air were lacking germination would not follow. This capital condition explains to us why seeds planted too deep fail to come up; why germination is much easier in soil that is mellow and can be permeated by the air than in soil that is [140]compact; why delicate seeds should be covered with very little earth or even simply sown on the surface of the moist ground; and, finally, why ground on being broken often becomes covered with fresh vegetation from the sprouting of seeds that have for years lain dormant in the soil, needing only to be stirred up and brought into contact with the air in order to germinate.

“Under like conditions of temperature, moisture, and air, by no means all seeds require the same length of time for germinating. Common garden cress germinates in about two days. Spinach, turnips, and beans take three days to come up; lettuce, four; melons and pumpkins, five; cereals, about a week. Two years and sometimes more are needed by the rose-bush, the hawthorn, and various stone-fruit trees. Generally seeds with thick and hard shells are slow in germinating on account of the obstacle they oppose to the penetration of moisture. Finally, when sown fresh, immediately after coming to maturity, seeds germinate quicker than when old, because old seeds have to recover by a prolonged sojourn in the ground the moisture lost through prolonged drying.

“According to their kind, seeds retain for a longer or shorter period their power of germinating; but why this vitality is more enduring in one instance and less so in another, we cannot tell. Neither the bulk of the seed nor the character of its outside coverings, nor the presence or absence of a perisperm, appears to decide its longevity. Such and such a [141]seed lives for whole years, even centuries, while another loses its germinating power in a few months, from no cause that we can discover. Thus the seeds of the angelica will not come up unless they are sown immediately after maturing; but beans have been known to germinate after being kept more than a hundred years, and rye after a hundred and forty. Excluded from the air, certain seeds may be kept for centuries, always ready to germinate whenever favorable conditions shall present themselves. This explains why strawberry, bluet, and camomile seeds from ancient tombs have germinated just as new seeds would have done. Finally, rush seeds have been made to germinate that were dug up from great depths in the Island of the Seine, the original site of Paris. Doubtless those seeds dated from the time when Paris, under the name of Lutetia, consisted of a few mud and reed huts on the marshy borders of the stream. But despite these remarkable exceptions let us never forget that recent seed is preferable to old for sowing; it comes up better and in greater abundance.

“We have just seen that certain seeds are very slow in coming up, as for example the peach, apricot, and plum, whose thick shells resist the moisture required for germination. Put directly into the ground in the very places that the young plants are to occupy later, these seeds would be exposed to not a few dangers during their leisurely germination. Prolonged rains might make them rot; various marauders that are partial to them, such as rats, field-mice, [142]jays, magpies, and crows, might dig them up and devour them. Besides, they would occupy for a long time, with no profit to any one, the ground in which they had been planted. All these objections are avoided by making a preliminary planting after a method known as stratification, from the Latin word stratum, meaning bed or layer. In a large, deep earthen pan, with holes in its bottom, or in any other suitable receptacle, such as a box, a pot, or a tub, likewise pierced with holes, it is the practice to place first a layer of small pebbles. The holes at the bottom and this layer of pebbles are to give easy access to the air and drain off the excess of water after each irrigation. Next comes a bed of fine sandy soil, then a layer or stratum of seeds arranged side by side, and on top of that a second bed of earth. On this is placed another stratum of seeds, which in its turn is covered with earth; and so the process goes on with alternating layers of seeds and earth until the receptacle is full. Then it is watered and placed in a cellar or a dark shed. All that is necessary after this is to keep the contents of pan or tub sufficiently moist by an occasional sprinkling. Enclosed thus in a small space easy to watch over, with no danger from marauding animals, and without needlessly occupying ground that might be used for other purposes, the seeds can now take their own time to break their hard shells and can germinate with all the slowness natural to them.

“When the shells at last crack open and the radicle appears, it is time to proceed to the final planting. [143]The half-germinated seeds are then put into the ground one by one in an open field, each at the exact spot the young plant is to occupy.

“Stratification offers still another advantage. Fruit trees as well as other trees have a stout tap-root which bores vertically into the ground to a considerable depth and gives a good deal of trouble if transplanting is undertaken. To alter this tap-root into a root not growing so deep, but branching horizontally, would be decidedly advantageous. In speaking of the root we saw what the nursery-man does to obtain this result. He passes the sharp edge of his spade under the base of each tree-trunk so as to sever the tap-roots of his young plantations. In stratification the method is much simpler and success surer. With his thumb-nail the gardener nips off the tip of the tender radicle before the final planting is done. That is all. Deprived of its growing end the young root henceforth branches out horizontally instead of descending vertically.”

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