42S MR. C. DARWIN ON THE ILLEGITIMATE OFFSPRIXO 



this pollen is identical with that of the short-styled Cowslip ; for 

 ten long-styled flowers of the common Cowslip were legitimately 

 fertilized by pollen from a true equal- styled variety, and produced 

 six capsules, containing on an average 34'4 seeds ; whilst seven 

 capsules on a short styled Cowslip illegitimately fertilized by the 

 same pollen yielded an average of only 14-5 seeds. 



As the eighteen equal-styled and so-called short-styled plants 

 differ from each other in their powers of reproduction, and as this 

 is an important subject, I will give a few details with respect to 

 five of them. Pirst, an equal-styled plant, protected from insects 

 (as in all the following cases, with one stated exception), spon- 

 taneously produced numerous capsules, five of which gave an 

 average of 44*8 seeds, with a maximum in one capsule of 57. 

 But six capsules, which had been fertilized by pollen from a short- 

 styled Cowslip (and this is a legitimate union), gave an average of 

 28*5 seeds, with a maximum of 49 ; and this is a much lower average 

 than might have been expected. Secondly, nine capsules from an 

 equal-styled plant, which was not protected from insects, but 

 probably was self-fertilized, gave an average of 45*2 seeds, with a 

 maximum of 58. Thirdly, a plant which had a very short pistil 

 in 1865, produced spontaneously many capsules, six of which con- 

 tained an average of 33-9 seeds, with a maximum of 38. In 1866 

 this same plant had a pistil of wonderful length ; for it projected 

 quite above the anthers, and the stigma resembled that of the 

 long-styled form. In this condition it produced spontaneously a 

 yast number of fine capsules, six of which contained almost exactly 

 the same average number as before, viz. 34*3, with a maximum of 

 38. Four flowers on this plant, legitimately fertilized by pollen 

 from a short-styled cowslip, yielded capsules with an average of 

 30"2 seeds. Fourthly, a short-styled plant spontaneously pro- 

 duced in 1865 an abundance of capsules, ten of which contained 

 an average of 35*6 seeds, with a maximum of 54, In 1866 it 

 had become in all respects long-styled, and ten capsules gave 

 almost exactly the same average, viz. 35*1 seeds, with a maxi- 

 mum of 47. Eight flowers on this plant, legitimately fertilized 

 by pollen from a short-styled. Cowslip, produced six capsules, with 

 the high average of 53 seeds, and the high maximum of 67. Eight 

 flowers were also fertilized by pollen from a long-styled Cowslip 

 (this being an illegitimate union), and produced seven capsules, con- 

 taining an average of 24*4 seeds, with a maximum of 32. The fifth 

 and last plant remained in the same condition during both years: it 

 had a pistil rather longer than that of the true short-styled form, 



