Page:Treatise on Cultivation of the Potato.djvu/35

 to maintain that varieties are individuals; and as they are born they must die, like other individuals; and I submit that I have proven it to demonstration by dividing a plant longitudinally into two equal parts, by cutting down exactly through the centre of the pith, by leaving to each half an equal quantity of roots, and by growing it in separate parts of space. I submit that the experiment cannot be got over, and that the question is settled; that plants cannot be propagated for ever by their buds.

In my judgment, a tree is not a multitude of individual lives residing in one common structure, but on the contrary a tree and its buds, and the forest which may be derived from them by cuttings, is only one individual life residing in a multitude of structures. I see it and I feel it, or at least it seems to me to be visible and palpable.

Let a branch of a plant be converted into a layer, it puts forth adventitious roots, and through them it obtains nourishment, at the same time setting up the commencement of a duplicate sap circulation, and it is still unquestionably a branch of the original plant whatever a branch or a bud may be considered to be; for, sever the adventitious roots, and it resumes its original position as a common branch of the plant.

Now sever the connection with the stem, let it enter on a separate existence for itself upon its adventitious roots, and what is it? A new individual freshly born, endowed with a stock of life equal to that with which the plant from which it was severed was endowed, when it first started into life?

I think it is impossible; for where is the new birth, the new starting point of life? If anywhere, it must have been in the germination of the leaf-bud; but it could not have been there, because, if it had not been separated from the stem, it would have existed under the same conditions as the other unseparated buds, and all must have grown old together.

What then does this layer seem to me to be? Merely a separated branch of the original plant, animated by the same life, which derived its existence or rejuvenation rather, from the sexual union which generated the seed, which developed into the plant from which it was severed.

The supply of food through the roots of the original plant has been cut off, and the duplicate circulation of the sap has been fully