6 HYBRIDISM. [Chap. IX. 



as from the anthers of the flower itself which is to be fer- 

 tilised; so that a cross between two flowers, though 

 probably often on the same plant, would be thus effected. 

 Moreover, whenever complicated experiments are in 

 progress, so careful an observer as Gartner would have 

 castrated his hybrids, and this would have ensured in 

 each generation a cross with pollen from a distinct 

 flower, either from the same plant or from another 

 plant of the same hybrid nature. And thus, the strange 

 fact of an increase of fertility in the successive genera- 

 tions of artificially fertilised hybrids, in contrast with 

 those spontaneously self-fertilised, may, as I believe, be 

 accounted for by too close interbreeding having been 

 avoided. 



Now let us turn to the results arrived at by a third 

 most experienced hybridiser, namely, the Hon. and Eev. 

 W. Herbert. He is as emphatic in his conclusion that 

 some hybrids are perfectly fertile — as fertile as the pure 

 parent-species — as are Kolreuter and Gartner that some 

 degree of sterility between distinct species is a universal 

 law of nature. He experimented on some of the very 

 same species as did Gartner. The difference in their 

 results may, I think, be in part accounted for by 

 Herbert's great horticultural skill, and by his having 

 hot-houses at his command. Of his many important 

 statements I will here give only a single one as an ex- 

 ample, namely, that " every ovule in a pod of Crinum 

 capense fertilised by C. revolutum produced a plant, 

 which I never saw to occur in a case of its natural fecun- 

 dation." So that here we have perfect or even more 

 than commonly perfect fertility, in a first cross between 

 two distinct species. 



This case of the Crinum leads me to refer to a 



