Plant-breeding; comments on the experiments of Nilsson and Burbank . cognizable in their youth by their narrow leaves. Thealbida is whitish and very deHcate and has its pecuhar shapeof spikes and flowers. The kcvifolia combines smoothleaves with a propensity for reducing the petals on the weakerbranches to an ovate form. But the most interesting instanceand the one which almost exactly corresponds to the corre-lation between botanical and practically valuable charactersof the agricultural crops is that of the CEnothera gigas. Itsbotanical marks are the dense f oh age, the large flowers, theswo
Plant-breeding; comments on the experiments of Nilsson and Burbank . cognizable in their youth by their narrow leaves. Thealbida is whitish and very deHcate and has its pecuhar shapeof spikes and flowers. The kcvifolia combines smoothleaves with a propensity for reducing the petals on the weakerbranches to an ovate form. But the most interesting instanceand the one which almost exactly corresponds to the corre-lation between botanical and practically valuable charactersof the agricultural crops is that of the CEnothera gigas. Itsbotanical marks are the dense f oh age, the large flowers, theswollen flower-buds, and the small, but thick pods \\ath theirless numerous, but bigger seeds. Its cultural feature is itsgreat tendency to be biennial. The parent species andmost of its other derivatives can easily be cultivated as an-nuals, and the rubriner\is evidently prefers this the other hand, the gigas prefers to develop its stems onlyin the second year. Under the conditions existing in myexperimental garden, it ordinarily defies all endeavors to. Fig. 104. Spikes with almost ripe fruits of A. Oenothera gigas, a mutantspecies. B. Oenothera Lamarckiana, its parent form. 329 330 PLANT-BREEDING make it flower and produce seeds in its first year. Ordina-rily at least one half of the plants remain in the rosette stage,the remainder producing their stems only late in summeror towards the fall, and thus having hardly time enough todisplay their flowers, and none at all to ripen their fruits. ^Ij^^ ^« - A 3 Fig. 105. A. A rosette of rootlcaves of Lamarcks Evening-primrosein September. B. A similar rosette of one of its mutants (OfH. Jc/«////a«5)in the same age. Only in some very favorable years have I succeeded in savingseed from annual gigas plants. Here we have an instance of correlation such as thatbetween hairiness or form of scales and hardiness in winteror resistance to diseases. But here the mutative origin ofthe type affords a direct proof of the vaUdity of
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