350 SELF-FEBTILE VABIETIES. CHAP. IX. 



those which were crossed ; and the seedlings raised 

 from these self-fertilised seeds exceeded in height 

 those raised from the crossed seeds to an extraordinary 

 degree. In the second and third generations, although 

 the self-fertilised plants did not exceed the crossed in 

 height, yet their self-fertilised flowers yielded on two 

 occasions considerably more seeds than the crossed 

 flowers, even than those which were crossed with pollen 

 from a distinct stock or variety. 



Lastly, as certain individual plants of Reseda odorata 

 and lutea are incomparably more self-fertile than other 

 individuals, the former might be included under the 

 present heading of the appearance of new and highly 

 self-fertile varieties. But in this case we should have 

 to look at these two species as normally self-sterile ; 

 and this, judging by my experience, appears to be the 

 correct view. 



We may therefore conclude from the facts now given, 

 that varieties sometimes arise which when self-fer- 

 tilised possess an increased power of producing seeds 

 and of growing to a greater height, than the inter- 

 crossed or self-fertilised plants of the corresponding 

 generation all the plants being of course subjected 

 to the same conditions. The appearance of such 

 varieties is interesting, as it bears on the existence 

 under nature of plants which regularly fertilise them- 

 selves, such as Ophrys apifera and some other orchids, 

 or as Leersia oryzvides, which produces an abundance 

 of cleistogamic flowers, but most rarely flowers capable 

 of cross-fertilisation.* 



Some observations made on other plants lead me 

 to suspect that self-fertilisation is in some respects 

 beneficial ; although the benefit thus derived is as a 



* On Leersia, see ' Different Forms of Flowers,' &c., p. 335. 



