Page:Popular Science Monthly Volume 66.djvu/219

Rh, one of them bearing rose-colored flowers. From the mountain ash and blackberry a salmon-colored fruit with no thorns and no albumen in the seed was developed. A hybrid between the English and the black walnut grows fully four times as fast as the English walnut; it bears little fruit. The seedlings from the fruit produce some English, some black, and some hybrid walnuts, and not rarely entirely new forms. Crossing often brings about great vegetative life at the expense of reproductive life, or the reverse. The young (second generation) hybrids of the black walnut and the English walnut show very great variation in their leaves, resembling neither parent. The hybrids of the English and California black walnuts are most rapidly growing trees and unusually productive. The first hybrid, of the English with the Japanese walnut, Juglans sieboldi, is largely like the Japanese in the nuts, but rather more like the English in foliage, the second generation being very variable as usual.

By crossing types already crossed, we may often bring out the original stock which had been lost in cultivation. The English walnut has usually five leaflets, the black walnut fifteen to nineteen. The first

generation hybrid has eleven, with a fragrance to the leaves that no original walnut has. This tendency or trait is just as real as any other. The American walnut (Juglans nigra) and the California black walnut (J. californica) are closely related species and when hybridized yield fruit of very large size and in enormous quantities.