The same argument holds true for the higher plants, which have become purely asexual under the influence of cultivation. I refer to many of the well-marked varieties of our cultivated plants which multiply exclusively, or almost exclusively, by means of tubers and slips, as is the case with the potato, the manioc, the sugar-cane, the arrowroot-plant (_Maranta arundinacea_), and others. All these facts can easily be reconciled with our interpretation of the meaning of amphimixis, although the attempt to range them as evidence against our theory has more than once been made. We have thus arrived at the conclusion that while many-sided adaptations, that is, variations which transform the plant in accordance with the indirect influences of new conditions of life, cannot be brought about without a persistent mingling of germ-plasms, simple modifications may readily appear although amphimixis is altogether absent. If a wild plant be permanently transferred to a well-manured culture-bed, it is probable that certain changes will occur in it, either gradually or at once. But these are not adaptations; they are, so to speak, direct reactions of the organism which do not even require selection to make them increase, but depend upon the influencing of certain determinants of the germ-plasm, and which, like all germinal variations, will follow their course steadily until a halt is called either by germinal or by personal selection. When a given plant is exposed to these new and artificial conditions, the changes in question make their appearance sooner or later, and follow their course, and go on increasing as long as that is compatible with the harmony of the structure and functioning of the plant, this depending, as in all individual development, on the struggle between the parts, that is to say, on histonal selection. Only in this respect is the utility or injuriousness of the change of importance, for personal selection, the struggle between individuals, does not affect plants which are under cultivation.