Have any of your readers ever used stones purposely in potting such things as Vines and Pines? It is the custom to pick these carefully out of the compost before using it; and I confess, myself, to a prejudice against them hitherto, though I am not prepared, I must admit, to give a very good reason for the same. I am led to ask the above question from an idea which occurred to me the other day when examining the roots of a Pine-Apple plant which had been turned out of the pot. As has often been observed in the case of potted plants, the roots were all at the side of the pot. Just to see how far they had availed themselves of the body of soil between the stem and the pot, I poked the soil out at the bottom of the ball from the top. So few were the roots, comparatively, that this could be done easily, leaving just the skeleton of the ball - a thick mat, which had formed at the sides of the pot, and inside nothing but a few strong roots radiating from the stem of the plant to the outside of the ball, where they had congregated and thickened, without the least disposition to turn back and take advantage of the bulk of rich soil they had left behind.

I estimated that the roots had availed themselves of about one-third or one-half of the soil in the 12-inch pot, living principally - after they had eaten the strength out of this - upon the nourishment supplied in the waterings. No doubt it was observation of this kind which led to the practice of shifting plants forward by inches, in order that the roots might be compelled to eat their way through in a regular manner; and there is reason in the practice, though in the case of the Pine-Apple the many-shift system is not a good one. Still, if by any other practice we could produce the same results it would certainly be advantageous. If a good plant can be grown in a 12-inch pot upon only one-half the diet supplied, it would doubtless be a much better specimen if it could be induced to take it all; and a 10 or 12 inch pot contains no more soil than a strong Pine-plant requires, but it is unable to avail itself of the store under the circumstances, and it is therefore lost. It is the same with pot-Vines and other plants, but to a less extent, perhaps; for the Pine has a very bad habit of warping its roots round the sides of the pot, especially when it is potted loosely.

It would appear, therefore, that to make the roots occupy the soil in the pot regularly as they progress, they must be obstructed in their passage. Hard potting will do this to a great extent, but it is not entirely effectual in preventing the majority of the roots from establishing themselves at the side of the pot. It seems to me, therefore, that a fair proportion of stones among the soil would effectually bar their direct progress. Round boulders would be too bulky, but flat slaty stones, introduced vertically here and there between the stem and the pot at potting time, would necessarily cause the roots to break up into branchlets and seek a more roundabout way to their ultimate destination - utilising, at the same time, the body of soil at their disposal, which they would otherwise have disregarded.

Supposing we could accomplish the end in view, it seems certain that less-sized pots would do, and two pots of a given size would give better results. I have frequently noticed, as others must have done, that the ball of an old Pine-plant, when squeezed with the foot, would burst its skin, and the contents, soil and bones, scarcely touched with,a root, would fall out in much the same condition as when the plant was first potted, except that the bones in the soil were just in that state in which the roots like to find them for immediate use.

J. S.