Page:Treatise on Cultivation of the Potato.djvu/36

 established. The one life now flows through two circles, but the origin is the same, and so by necessary consequence is its duration. The layer, therefore, and the original plant must both die of old age at the same time, on the expiration of the term of life alloted to the seed from which they both alike sprang; and the same law must apply to all the successive layers, suckers, grafts, &c., which may be derived from them.

They are all so many circulations of the same individual (and, as I think, indivisible) life; because they all spring from the same sexual union, the sole origin of all life—all individual life. That is, provided (as I assume) that vegetative multiplication does not afford a new starting point of life—is not equivalent to the sexual union. And what reason is there to suppose that it is? The duration of the life of plants is yet unknown, and therefore the periods of time through which they may be continued or multiplied by buds is also unknown; it is, no doubt, in some instances, thousands of years; but that fact is no evidence that another law of reproduction is in existence, or that the sexual union is not amply sufficient for the propagation and multiplication of individuals. It is more than sufficient, because it always eventuates in the production of surplus populations, and in the seemingly inequitable destruction of the vast majority of its products—the multitude of the un-fittest.

And relative to this law of vegetative multiplication, this incomprehensibly vast power of self-extension of plants, by virtue of their inherent vegetative energy, by which they absorb and organize enormous quantities of matter through immense ranges of time—it has not yet been measured, and therefore, as it seems, it has been assumed to be "unlimited." But I think it will be found to have a limit, and that that limit is the exhaustion of the stock of life generated by the sexual union. It appears to be wonderful that a seed of the potato should have the capacity of developing itself into an aggregate which, in one year's produce, might perhaps, cover the half of England, but if it be a fact, it must be accepted of as such, and after all, it is no more and no less wonderful than the law of true reproduction.

It is stated that "the sugar cane is propagated naturally by the stem; strawberries, by runners; potatoes by tubers, &c."; and of plants generally, that "their organizing forces are diffused through