Only a few observations were made during 1867. The results are arranged in classes according to the parentage of the plants. In each case the average number of seeds per capsule is given, generally taken from ten capsules, which, according to my experience, is a nearly sufficient number. The maximum number of seeds in any one capsule is also given; and this is a useful point of comparison with the normal standard--that is, with the number of seeds produced by legitimate plants legitimately fertilised. I will give likewise in each case the minimum number. When the maximum and minimum differ greatly, if no remark is made on the subject, it may be understood that the extremes are so closely connected by intermediate figures that the average is a fair one. Large capsules were always selected for counting, in order to avoid over-estimating the infertility of the several illegitimate plants.
In order to judge of the degree of inferiority in fertility of the several illegitimate plants, the following statement of the average and of the maximum number of seeds produced by ordinary or legitimate plants, when legitimately fertilised, some artificially and some naturally, will serve as a standard of comparison, and may in each case be referred to. But I give under each experiment the percentage of seeds produced by the illegitimate plants, in comparison with the standard legitimate number of the same form. For instance, ten capsules from the illegitimate long-styled plant (Number 10), which was legitimately and naturally fertilised by other illegitimate plants, contained on an average 44.2 seeds; whereas the capsules on legitimate long-styled plants, legitimately and naturally fertilised by other legitimate plants, contained on an average 93 seeds. Therefore this illegitimate plant yielded only 47 per cent of the full and normal complement of seeds.
STANDARD NUMBER OF SEEDS PRODUCED BY LEGITIMATE PLANTS OF THE THREE FORMS, WHEN LEGITIMATELY FERTILISED.
Long-styled form: Average number of seeds in each capsule, 93; Maximum number observed out of twenty-three capsules, 159.
Mid-styled form: Average number of seeds, 130; Maximum number observed out of thirty-one capsules, 151.
Short-styled form: Average number of seeds, 83.5; but we may, for the sake of brevity, say 83; Maximum number observed out of twenty-five capsules, 112.
CLASSES 1 AND 2. ILLEGITIMATE PLANTS RAISED FROM LONG-STYLED PARENTS FERTILISED WITH POLLEN FROM THE MID-LENGTH OR THE SHORTEST STAMENS OF OTHER PLANTS OF THE SAME FORM.
From this union I raised at different times three lots of illegitimate seedlings, amounting altogether to 56 plants. I must premise that, from not foreseeing the result, I did not keep a memorandum whether the eight plants of the first lot were the product of the mid-length or shortest stamens of the same form; but I have good reason to believe that they were the product of the latter. These eight plants were much more dwarfed, and much more sterile than those in the other two lots. The latter were raised from a long-styled plant growing quite isolated, and fertilised by the agency of bees with its own pollen; and it is almost certain, from the relative position of the organs of fructification, that the stigma under these circumstances would receive pollen from the mid-length stamens.
All the fifty-six plants in these three lots proved long-styled; now, if the parent-plants had been legitimately fertilised by pollen from the longest stamens of the mid-styled and short-styled forms, only about one-third of the seedlings would have been long-styled, the other two-thirds being mid-styled and short-styled. In some other trimorphic and dimorphic genera we shall find the same curious fact, namely, that the long-styled form, fertilised illegitimately by its own-form pollen, produces almost exclusively long-styled seedlings. (5/1. Hildebrand first called attention to this fact in the case of Primula Sinensis ('Botanische Zeitung' January 1, 1864 page 5); but his results were not nearly so uniform as mine.)
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 47 inches; whilst legitimate plants growing close by were double this height, one being 77 inches. They all betrayed in their general appearance a weak constitution; they flowered rather later in the season, and at a later age than ordinary plants.