218 ILLEGITIMATE OFFSPRING OF Chap. V. 



incestuous marriages, if they continued to marry in- 

 cestuousiy, would have their sterility only slightly 

 increased ; but their fertility would not be restored by 

 a proper marriage; for if two children, both of in- 

 cestuous origin, but in no degree related to each 

 other, were to marry, the marriage would of course be 

 strictly legitimate, nevertheless they would not give 

 birth to more than half the full and proper number 

 of children. 



Eqtial-styled variety of 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. My attention was first called to the subject by ob- 

 serving, in 1862, a long-^yled plant, descended from a self- 

 fertilised long-styled parent, which had some of its flowers in an 

 anomalous state, namely, with the stamens placed low dowa 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 globular 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 combined in the 

 same flower, the short stamens of the long-styled form with a 

 pistil closely resembling that of the short-styled form. But 

 the structure varied much even on the same umbel : for in two 

 flowers the pistil was intermediate in length between that of 

 the long and that of the short-styled form, with the stigma 

 elongated as in the former, and smooth as in the latter; and in 

 three other flowers the structure was in all respects like that of 

 the long-styled form. These modifications appeared to mo so 

 remarkable that I fertilised eight of the flowers with their own 

 pollen, and obtained five capsules, which contained on an aver- 

 age 43 seeds; and this number shows that the flowers had 

 become abnormally fertile in comparison with those of ordinary 

 long-styled plants when self-fertilised. I was thus led to ex- 

 amine the plants in several small collections, and the result 

 showed that the equal-styled variety was not rare. 



In a state of nature the long and short-styled forms would no 

 doubt occur in nearly equal numbers, as I infer from the analogy 

 of the other heterostyled species of Primula, and from having 



