Page:Treatise on Cultivation of the Potato.djvu/61

 prolific and as palatable as it, can be obtained with the utmost facility? And of those which resist the first year, and fail in any succeeding years—destroy, destroy, destroy. It is the principle of "natural selection" artificially carried out, and it is done every day in animal life, and with results beyond, far beyond, what could possibly have been anticipated beforehand. If it were applied to the human race, how the matttermatter [sic] of the better cultivation of a plant would fade into nothingness, by comparison. As to manures, let the sets in the middle row have a full dose of farm-yard manure, if possible containing seeds of the parasite. For the seedlings I cannot say; if the soil is good, I think, perhaps, they are as well without it. Before planting out the seedlings, they should be "hardened off." At all times except in frost, the conservatory should have a full supply of air. I do not think, with Mr. Knight, that artificial heat is requisite, at least in the latitude of Belfast, when the seed is sown after first of April. Where a conservatory is not available, a hot-bed, or cold frame, or warm border will answer, only the plants must be protected from frost. My plants, all or almost, all blossomed, not one in 500 bore fruit; neither in the conservatory, hot-bed, cold frame or field. I do not understand this. I know all the old "varieties" are seedless, and I thought the young would have produced their seed freely the first year. There seems to be some analogy or relationship here to the perennial plants; some of which do not blossom until after many years' growth. Red purplish flower occurred very rarely—the skerry blue has it, and it is one of the most nearly disease proof varieties now in cultivation; but its yield has fallen off to almost nothing. Cream coloured, pale, blue, pink and purple flowers are common. The second, third,—several pairs of the lower leaves, attain a length of 14 to perhaps 18 inches from axilla to tip of blade. Blade of terminal leaf 4 or 5 inches broad, 6 or 7 inches long. The upper and later produced leaves are of the usual size.

In regard to this matter, every one will ask, what does Mr. Darwin say? He says, and it will be generally admitted that there is no higher authority in the world—he says:—(The Variation of Animals and Plants under Domestication Vol. II. page 362. Murray, 1868.