218 ILLEGITIMATE OPPSPEING OP Chap. V. 



mankind six children would be born on an average from 

 an ordinary marriage; but that only three would be 

 born from an incestuous marriage. According to the 

 analogy of Primula Sinensis, the children of such 

 incestuous marriages, if they continued to marry in- 

 cestuously, would have their sterility only slightly in- 

 creased; 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, neveiiheless they would not give 

 birth to more than half the full and proper number 

 of children. 



Equal-styled variety of Primula Sinensis. — As any vari- 

 ation 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 observing, in 1863, a long-styled plant, de- 

 scended from a self -fertilised long-styled plant, which had 

 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 stig- 

 mas 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 be- 

 tween that of the long- and that of the short-styled form, 

 with the stigma elongated as in theformer, 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 me so remarkable that I fertilised 

 eight of the flowers with their own pollen, and obtained 

 five capsules, which contained on an average 43 seeds ; and 

 this number shows that the flowers had become abnormally 

 fertile in comparison with those of ordinary long-styled 



