OF DIMORPHIC \NI> TRIMORVHIC PLANTS. 429 



with the stigma smooth, as it ought to he in this form, hut ahnorilial 

 in shape, like a much-elongated inverted cone. It produced spon- 

 taneously manj capsules, five of w hich, in 1865, gave an average of 

 only 15*6 seeds ; and in 1866 ten capsules still gave an average only 

 a little higher, \h, of 22*1, with a maximum of 30- Sixteen flowers 

 were fertilized by pollen from a long-styled Cowslip, and produced 

 12 capsules, with an average of 24*9 seeds and a maximum of 42. 

 Eight flowers were fertilized by pollen from a short-styled Cow- 

 slip, but yielded only two capsules, containing 18 and 23 seeds. 

 Hence this plant, in function and partially in structure, is in an 

 almost exactly intermediate state between the long-styled and 

 short-styled form, but inclining towards the short-styled ; and this 

 accounts for the low average of seeds Avhich it produced when 



spontaneously self-fertilized. 



We thus see that the foregoing five plants diflfer much from 

 each other in fertility. In two individuals a great difference in 

 the length of the pistil during two succeeding years made no dif- 

 ference in the number of seeds produced. As all five plants pos- 

 sessed the male organs of the short-styled form in a perfect state, 

 and the female organs of the long-styled form in a more or less com- 

 plete state, they spontaneously produced a surprising number of 

 capsules, which generally contained a large average of remarkably 

 good seeds. With ordinary Cowslips, legitimately fertilized, I once 

 obtained from plants cultivated in tlie greenhouse the high average, 

 from seven capsules, of 58*7 seeds, with a maximum in one capsule 

 of 87 seeds ; but from plants grown out of doors I never obtained 

 a higher average than 41 seeds. Now two of the equal-styled 

 plants, grown out of doors and spontaneously self-fertilized, gave 

 averages of 44 and 45 seeds ; but this high fertility may perhaps 

 be attributed to the stigma receiving pollen from the surrounding 

 anthers at exactly the right period. Two of these plants, fertilized 

 ^y pollen from the long-styled cowslip (and this in fact is a 

 legitimate union), gave a lower average than when self-fertilized. 

 On the other hand, one plant, when similarly fertilized by the 

 Cowslip, yielded the unusually high average of 53 seeds, with a 

 maximum of 67. Lastly, as we have just seen, one of these plants 

 was in an almost exactly intermediate condition in its female 

 organs between the long- and short-styled forms, and consequently, 

 when self-fertilized, yielded a low average of seed. If we add to- 

 gether all the experiments which I made on the equal-styled plants, 

 41 spontaneously self-fertilized capsules (insects having been 

 excluded) gave an average of 34 seeds, which is exactly the same 



