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Show 192 ILLEGI'fiMArrE OFFSPRING OF CHAP. v. plant growing quite isolated, and fertilised by the agency of bees with its own pollen; and it is almost certain, fro1n the relative position of the organs of fructification, that the stigma under these circumstances would receive pollen from the mid -length sta1nens. All the fifty-six plants in these three lots proved longstyled ; now, if the parent-plants had been legitin1ately fertilised by pollen fro1n the longest stamens of the mid-styled and short-styled forms, only about onethird of the seedlings would have been long-styled, the other two-thirds being mid-styled and short-styled. In some other tri1norphic and di1norvhic genera we shall find the same curious fact, namely, that the longstyled form, fertilised illegitimately by its own-form pollen, produces almost exclusively long-styled seedlings.* The eight plants of the first lot were of low stature: three which I measured attained, when fully grown, the heights of only 28, 29, and 4 7 inches; whilst legitimate plants growing close by were double this height, one being 77 inches. They all bet1~a yed in their general appearance a weak constitution ; they flowered rather later in the season, and at a later age than ordinary plants. Some did not flower every year ; and one plant, behaving in an unprecedented manner, did not flower until three years old. In the two other lots none of the plants grew quite to their full and proper height, as could at once be seen by comparing then1 with the adjoining rows of legitimate plants. In several plants in all three lots, many of the anthers were either shrivelled or contained brown and tough, or pulpy * Hildebrand first cRll8d attention ·(' Bot. Zeitung,' Jan. 1, 1864, p. 5) to this fact in the case of P.rimula Sinensis ; but his results were not nearly so uniform as mine. CHAP. V. HE'rEROSTYLED 'rRIMORPHIC PLANTS. 193 matter, without any good pollen-grains, and they never shed their contents; they were in the state designated by Gartner* as con tabescent, which term I will for the future use. In one flower all the anthers were contabescent excepting two which appeared to the naked eye sound; but under the microscope about two-thirds of the pollen-grains were seen to be small and shrivelled. In another plant, in which all the anthers appearG::l sound, many of the pollen-grains were shrivelled and of unequal sizes. I counted the seeds produced by seven plants (1 to 7) in the first lot of eight plants, probably the product of parents fertilised by their own-form shortest stamens, and the seeds produced by three plants in the other two lots, almost certain! y the product of parents fertilised by their own-form midlength stamens. Plant 1. This long-styled plant was allowed during 1863 to be freely and legitimately fertilised by an adjoining illegitimate mid-styled plant, but it did not yield a single seed-capsule. It was then removed and planted in a remote place close to a brother long-styled plant No. 2, so that it must have been freely th~ugh illegitimately fertilised ; under these circumstances it did not yield during 1864 and 1865 a single capsule. I should here state that a legitimate or ordinary long-styled plant, when growing isolated, and freely though illegitimately fertilised by insects with its own pollen, yielded an immense number of capsules, which contained on an average 21· 5 seeds. Plant 2. This long-styled plant, after flowering during 1863 close to an illegitimate mid-styled plant, produced less than twenty capsules, which contained on an average between four and five seeds. When subsequently growing in company with No. 1, by which it will have been illegitimately fertilised, it yielded in 1866 not a single capsule, but in 1865 it yielded twenty-two capsules: the best of these, fifteen in number, were examined; eight contained no seed, and the remaining seven contained on an average only three seeds, and these scocls were * 'Beitrage zur Kenntniss der Befruchtung,' 1844, p. 116. 0 |