In our time flowers and fruits are changing nearly as rapidly as the fancies and tastes of men. Every year new forms are introduced and usurp the place of older ones. Many are soon forgotten. But if we look at old country gardens, a goodly number of fine and valued old sorts are still to be found. It would be worth while to make special collections of living plants of old varieties, which surely would be a good and interesting work and bring about a conviction [166] of the stability of pure strains. Coming now to the other side of the question, we may consider those cases of reversion which have been recorded from time to time, and which always have been considered as direct proofs of the varietal character of the reverting form. Reversion means the falling back or returning to another type, and the word itself expresses the idea that this latter type is the form from which the variety has arisen. Some instances of atavism of this kind are well known, as they are often repeated by individuals that are multiplied by buds or by grafting. Before looking attentively into the different features of the many cases of rare reversions it will be advisable to quote a few examples. The flowering-currant of the Pacific Coast or North American scarlet ribes (_Ribes sanguineum_), a very popular ornamental shrub, will serve as a good example. It is prized because of its brilliant red racemes of flowers which blossom early in the spring, before the appearance of the leaves. From this species a white form has arisen, which is an old and widely cultivated one, but not so highly prized because of its pale flowers. These are not of a pure white, but have retained a faint reddish hue. The young twigs and the stalks of the [167] leaves afford an instance of correlated variability since in the species the red color shows itself clearly mixed with the green, while in the variety this tinge is wholly wanting. Occasionally this white-flowered currant reverts back to the original red type and the reversion takes place in the bud. One or two buds on a shrub bearing perhaps a thousand bunches of white flowers produce twigs and leaves in which the red pigment is noticeable and the flowers of which become brightly colored. If such a twig is left on the shrub, it may grow further, ramify and evolve into a larger group of branches. All of them keep true to the old type. Once reverted, the branches remain forever atavistic. It is a very curious sight, these small groups of red branches among the many white ones. And for this reason attention is often called to it, and more than once I myself have had the opportunity of noting its peculiarities. It seems quite certain that by planting such shrubs in a garden, we may rely upon seeing sooner or later some new buds reverting to the prototype.