of packing seeds for distant journeys has, in general, been to exclude the air, and all other considerations have been subordinate to this. Enclosure in bottles hermetically sealed, in papers thickly coated with wax, in tin boxes, and similar contrivances, have been resorted to with this object in view: but no advantage can be derived from excluding the air, and the disadvantage is very great; for the effect of excluding the air is to include whatever free moisture seeds may contain or be surrounded by; this moisture is sufficient, in high temperatures, either to deprive the seed of its carbon of preservation, or to induce decay of the tissue, especially of the seed coats, which have no vitality themselves, and in either case the embryo perishes.

Packing in charcoal has been recommended, it is difficult to say why; and experience shows what might have been anticipated, that it produces no other effect than packing in earth or other dry nonconducting material.

Clayed sugar has been employed, and, as it is said, occasionally with advantage; but I have seen no instance of success, and, on the contrary, its tendency to absorb moisture from the air till it becomes capable of fermenting, is in itself an objection to the employment of this substance.

The most common method of packing is to enclose seeds in paper, to surround parcels of such papers with envelopes of the same material, and to

enclose the whole in a deal box. It is in this manner that seedsmen usually despatch their orders to India, and other distant parts of the world. The evils of this method have been pointed out by Dr. Falconer, in the Proceedings of the Horticultural Society, vol. i. p. 49. "On one occasion," he says, "I received from England a large assortment of garden vegetable seeds, from a London seedsman. They were packed in the thick dark brown paper which is generally used by grocers and seedsmen, and which, for the facility of folding, is usually in a somewhat damp state. The packages were nailed up in a large wooden box, with numerous folds of this paper, and the box was then hermetically sealed in a tin case; it then found its way into the ship's hold. The damp paper, which in the temperature of England, say at 50°, would have mattered little, became an important agent when the ship got into the tropics; at about 80° the damp became a hot vapour, and, when the seeds reached me, I found them all in a semi-pulpy and mildewed state."

Upon the whole, the only mode which is calculated to meet all the circumstances to which seeds are exposed during a voyage is, to dry them as thoroughly as possible, enclose them in coarse paper, and to pack the papers themselves very loosely in coarse canvass bags, not enclosed in boxes, but freely exposed to the air; and to insure their transmission in some dry well-ventilated place. Thus,

if the seeds are originally dried incompletely, they will become further dried on their passage; if the seed paper is damp, as it almost always is, the moisture will fly off through the sides of the bags, and will not stagnate around the seeds. It is true that, under such circumstances, the seeds will be exposed to the fluctuations of temperature, and to the influence of the atmosphere; but neither the one nor the other of these is likely to be productive of injury to the germinating principle. The excellence of this method I can attest from my own observation. Large quantities of seeds have been annually transmitted from India for many years, doubtless gathered with care, it is to be presumed prepared with every attention to the preservation of the vital principle, and certainly packed with all those precautions which have been erroneously supposed to be advantageous; the hopelessness of raising plants from such seeds has at length become so apparent, that many persons have altogether abandoned the attempt, and will not take the trouble to sow them when they arrive. But the seeds sent from India by Dr. Falconer, packed in the manner last described, exposed to all the accidents which those first mentioned can have encountered, have germinated so well, that we can scarcely say that the failure has been greater than if they had been collected in the south of Europe.

I have no doubt that the general badness of the

seeds from Brazil, from the Indian Archipelago, and from other intertropical countries, is almost always to be ascribed to the seeds having been originally insufficiently dried, and then enclosed in tightly packed boxes, whence the superfluous moisture had no means of escape.

For seeds containing oily matter, which are peculiarly liable to destruction (by their oil becoming rancid?), ramming in dry earth has been found advantageous; as in the case of the Mango.

CHAP. VIII.

OF PROPAGATION BY EYES AND KNAURS.

THE power of propagating plants by any other means than that of seeds depends entirely upon the presence of leaf-buds (fig. 16.), or, as they are technically called " eyes" (52.), which are in reality rudimentary branches in close connexion with the stem. All stems are furnished with such buds, which, although held together by a common system, have a power of independent existence under fitting circumstances; and, when called into growth, uniformly produce new parts, of exactly the same nature, with respect to each other, as that from which they originally sprang.

16

Under ordinary circumstances, an eye remains fixed upon the stem that generates it. There it grows, sending woody matter downwards over the alburnum, and a new branch upwards, clothed with leaves, and perhaps flowers: but it occasionally happens that eyes separate spontaneously from their mother stem, and when they fall upon the ground they emit roots and become new plants (p. 32. fig. 3.). This happens in several kinds of Lily, and in other genera.

Man has taken advantage of this property, and has discovered that the eyes of many plants, if separated artificially from the stem and placed in earth, will, under favourable circumstances, produce new plants, just as such eyes would have done if they had spontaneously disarticulated; hence the system of propagation by eyes, an operation employed only to a limited extent in actual practice, but which in theory seems applicable to all plants whatever. The only species very generally so increased