414 MB. C. DARWIN ON THE ILLEGITIMATE OPrSPBING 



form, twenty-four out of twenty-five of their illegitimate offspring 

 were short-styled. They were dwarfed in stature, and one lot of 

 grandchildren had so poor a constitution that four out of six plants 

 perished before flowering. The two survivors, Avhen illegitimately 

 fertilized by their own-form pollen, were rather less fertile than 

 they ought to have been ; but their loss of fertility was clearly 

 shown in a special and unexpected manner, namely when legiti- 

 mately fertilized by other illegitimate plants : thus altogether 

 eighteen flowers fertilized in this manner yielded twelve capsules, 

 which included on an average only 28*5 seeds, with a maximum of 

 forty -five. Now a legitimate short-styled plant would have yielded, 

 when legitimately fertilized, an average of sixty-four seeds, with a 

 possible maximum of seventy-four. This particular kind of in- 

 fertility will perhaps be best appreciated by a simile : we may 

 assume that six children would on an average be born from each 

 ordinary marriage ; but that only three would be born from an in- 

 cestuous marriage. Now, according to the analogy of Primula 

 sinensis^ the children of such incestuous marriages, if they con- 

 tinued to marry incestuously, would have their sterility only 

 slightly increased ; but their fertility would not be restored by a 

 proper marriage ; for if two children, both of incestuous origin, but 



degr 



course 



and 



children. 



Eqiial'Styled variety q/* Primula sinensis. — As any variation in 

 the structure of the reproductive organs, combined with changed 

 function, is a rare event, the following cases are worth giving in 

 detail. Mr. Scott, in his excellent paper on the reproductive 

 functions in the Primulaceae*, has recorded some analogous facts. 

 My attention was first called to the subject by observing, in 18G2, 

 a long-styled plant, descended from a self-fertilized long-styled 

 parent, with some of its flowers in an anomalous state, namely, with 

 the stamens placed low down in the corolla as in the ordinary 

 long-styled form, but with the pistils so short that the stigmas 

 stood on a level with the anthers. These stigmas were nearly as 

 globidar and as smooth as in the short-styled form, instead of being 

 elongated and rough as in the long-styled form. Here, then, we 

 have stamens of the long-styled form and a pistil closely resembling 

 that of the short-styled form combined in the same flower. But 



* Journal of Proc. Linn. Soc. Bot. vol, viii. (1861) p. 78 



