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Chapter 9

self-fertilised plant long cultivated under the same conditions.

We may further infer that the converse of this occurs when with plants which are self-fertile in their native country, but become self-fertile under different changed conditions)

(We know that self-fertilised seedlings are inferior in many respects to those from a cross with a distant individual; and as with plants in a state of nature [illeg] [na]turally pollen from the same flowers can hardly fail to be often placed by insects or by the wind [in] their stigmas, of the same flowers, It it seems at first sight highly probable [th]at self-fertility has been gradually acquired through natural selection in

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individuals are absolutely alike. Therefore we can hardly avoid believing the conclusion that differences of an analogous nature in the reproductive system are sufficient to excite the mutual action of the sexual elements, and that unless there be such differentiation fertility fails.)

The appearance of highly self-fertilised varieties. We have just seen that self-fertility is an extremely variable character in certain cases, & we have differ much in degree, both with the species of the same genus, & sometimes with the individuals of the same species. We shall now to consider facts, observed on two probably on this three occasions, of the appearance of on two or three occasions of the varieties, which when self-fertilised were more fertile than their parents, or than the intercrossed plants of the corresponding generation.