Different Forms of Flowers on Plants of the Same Species

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152 HETEROSTYLED TRIMORPHIC PLANTS. CHAP. IV. ones even more sterile than they otherwise would have been. I have seen striking instances of this fact in making illegitimate and legitimate unions with Pri­mula; and it is well known that the conditions of life must be highly favourable to give any chance of suc­Qess in producing hybrids between species which are crossed with difficulty. TABLE 23.-Long-styled Form. I. Legitimate union. 13 flowers fertilised by the longest stamens of the mid-sty led. These stamens equal in length the pistil of the long-styled. Product of good seed in each cap­sule. 36 81 0 0 0 45 41 53 0 0 0 0 0 38 per cent. of these flowers yielded capsules. Each capsule con­tained, on an average, 51· 2 seeds. III. Illegitimate union. 14 flowers fertilised by the short-est stamens of the mid-styled, 3 0 0 0 0 0 0 0 0 0 0 0 0 0 Too sterile for any average. II. Legitimate union. 13 flowers fertilised by the longest stamens of the short-styled. These stamens equal in length t he pistil of the long-styled. Product of good seed in each cap­sule. 159 104 43 119 96 poor seed. 96 103 99 0 131 0 116 114 84 per cent. of these flowers yielded capsules. Each capsule con­tained, on an average, 107 · 3 seeds. IV. Illegitimate union. 12 flowers fertilised by the mid­length stamens of .the short-styled. 20 0 0 0 0 0 0 0 0 0 0 0 Too sterile for any average. CHAP. IV. LYTHRUM SALICARIA. 153 TABLE 23.-Long-styled Form-continued. v. IUegitimate union. 15 flowers fertilised by own-form mid-length stamens. 2 10 0 23 0 0 0 0 0 0 0 0 0 0 0 Too sterile for any average. VI. Illegitimate union. 15 flowers fertilised by own-form shortest stamens. 4 8 4 0 0 0 0 0 0 0 0 0 0 0 0 Too sterile for any average. Besides the above experiments, I fertilised a consi­derable number of long-styled flowers with pollen, taken by a camel' s-hair brush, from both the mid­length and shortest stamens of their own form: only 5 capsules were produced, and these yielded on an average 14 · 5 seeds. In 1863 I tried a much better ex­periment: a long-styled plant was grown by itself, miles away from any other plant, so that the flowers could have received only their own two kinds of pol­len. The flowers were incessantly visited by bees, and their stigmas must have received successive applica­tions of pollen on the most favourable days and at the most favourable hours: all who have crossed plants know that this highly favours fertilisation. This plant produced an abundant crop of capsules; I took by chance 20 capsules, and these contained seeds in num her as follows :- 20 26 7 ~0 20 24 30 12 35 12 27 29 21 23 29 19 19 10 13 35