CHAP. IX. AND SELF-FERTILISED FLOWERS. 327 



as the self-fertilised flowers on the parent-plants, and 

 on their descendants of the second and third genera- 

 tions, produced more seeds than did the crossed 

 flowers ; but we shall recur to this case when we treat 

 of highly self-fertile varieties. 



It might have been expected that the difference in 

 fertility between the crossed and self-fertilised flowers 

 would have been more strongly marked in Table G-, in 

 which the plants of one set were derived from self- 

 fertilised parents, than in Table F, in which flowers on 

 the parent-plants were self-fertilised for the first time. 

 But this is not the case, as far as my scanty materials 

 allow of any judgment. There is therefore no evi- 

 dence at present, that the fertility of plants goes on 

 diminishing in successive self-fertilised generations, 

 although there is some rather weak evidence that 

 this does occur with respect to their height or growth. 

 But we should bear in mind that in the later genera- 

 tions the crossed plants had become more or less closely 

 inter-related, and had been subjected all the time to 

 nearly uniform conditions. 



It is remarkable that there is no close correspondence, 

 either in the parent-plants or in the successive genera- 

 tions, between the relative number of seeds produced 

 by the crossed and self-fertilised flowers, and the 

 relative powers of growth of the seedlings raised from 

 such seeds. Thus, the crossed and self-fertilised 

 flowers on the parent-plants of Ipomoea, Gesneria, 

 Salvia, Limnanthes, Lobelia fulgens, and Nolana pro- 

 duced a nearly equal number of seeds, yet the plants 

 raised from the crossed seeds exceeded considerably in 

 height those raised from the self-fertilised seeds. 

 The crossed flowers of Linaria and Viscaria yielded 

 far more seeds than the self-fertilised flowers; and 

 although the plants raised from the former were tallei 



