Chap. V. HETEROSTYLED DIMORPHIC PLANTS. 237 



slip (this being an illegitimate union), and produced seven 

 capsules containing 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, with the stigma smooth, as it ought to 

 be in this form, but abnormal in shape, like a much-elongated 

 inverted cone. It produced spontaneously many capsules, five 

 of which, in 1865, gave an average of only 15 '6 seeds; and in 

 1866 ten capsules still gave an average only a little higher, viz. 

 of 22 • 1, with a maximum of 30. Sixteen flowers were fertilised 

 with pollen from a long-styled cowslip, and produced 12 cap- 

 sules, with an average of 24 '9 seeds, and a maximum of 42. 

 Eight flowers were fertilised with pollen from a short-styled 

 cowslip, but yielded only two capsules, containing 18 and 23 

 seeds. Hence this plant, in fimction and partially in structure, 

 was 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 which it 

 produced when spontaneously self-fertilised. 



The foregoing five plants thus -differ much from one another in 

 the nature of their fertility. In two individuals a great difference 

 in the length of the pistil during two succeeding years made no 

 difference in the number of seeds produced. As all five plants 

 possessed 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 complete state, they spontaneously produced a surprising 

 number of capsules, which generally contained a large average 

 of remarkably fine seeds. With ordinary cowslips, legitimately 

 fertilised, I once obtained from plants cultivated in the green- 

 house 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. 

 Kow two of the equal-styled plants, grown out of doors and 

 spontaneously self-fertilised, gave averages of 44 and 45 seeds ; 

 but this high fertility may perhaps be in part attributed to the 

 stigma receiving pollen from the surrounding anthers at exactly 

 the right period. Two of these plants, fertilised with poUen 

 from a short-styled cowslip (and this in fact is a legitimate 

 union), gave a lower average than when self-fertilised. On the 

 other hand, another plant, when similarly fertilised by a 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 



