The Different Forms of Flowers on Plants of the Same Species Part 13

92 0 9 0 63 0 - 0 136?* 0 0 0 0

(4/6. * I have hardly a doubt that this result of 136 seeds in Table 4.24.5 was due to a gross error. The flowers to be fertilised by their own longest stamens were first marked by "white thread," and those by the mid-length stamens of the long-styled form by "white silk;" a flower fertilised in the later manner would have yielded about 136 seeds, and it may be observed that one such pod is missing, namely at the bottom of Table 4.24.1. Therefore I have hardly any doubt that I fertilised a flower marked with "white thread" as if it had been marked with "white silk." With respect to the capsule which yielded 92 seeds, in the same column with that which yielded 136, I do not know what to think. I endeavoured to prevent pollen dropping from an upper to a lower flower, and I tried to remember to wipe the pincers carefully after each fertilisation; but in making eighteen different unions, sometimes on windy days, and pestered by bees and flies buzzing about, some few errors could hardly be avoided. One day I had to keep a third man by me all the time to prevent the bees visiting the uncovered plants, for in a few seconds' time they might have done irreparable mischief. It was also extremely difficult to exclude minute Diptera from the net. In 1862 I made the great mistake of placing a mid-styled and long-styled under the same huge net: in 1863 I avoided this error.)

Excluding the capsule with 136 seeds, 25 percent of the flowers yielded capsules, and each capsule contained, on an average, 54.6 seeds; or, excluding capsules with less than 20 seeds, the average is 77.5.

TABLE 4.24.6. Illegitimate union.

12 flowers fertilised by own-form shortest stamens.

0 0 0 0 0 0 - 0 0 0 0 0 0

Not one flower yielded a capsule.

Besides the experiments in Table 4.24, I fertilised a considerable number of mid-styled flowers with pollen, taken by a camel's-hair brush, from both the longest and shortest stamens of their own form: only 5 capsules were produced, and these yielded on an average 11.0 seeds.

TABLE 4.25. Lythrum salicaria, short-styled form.

TABLE 4.25.1. Legitimate union.

12 flowers fertilised by the shortest stamens of the long-styled. These stamens equal in length the pistil of the short-styled.

69 56 61 88 88 112 66 111 0 62 0 100 -

83 percent of the flowers yielded capsules. Each capsule contained, on an average, 81.3 seeds.

TABLE 4.25.2. Legitimate union.

13 flowers fertilised by the shortest stamens of the mid-styled. These stamens equal in length the pistil of the short-styled.

93 69 77 69 48 53 43 9 0 0 0 0 - 0

61 percent of the flowers yielded capsules. Each capsule contained, on an average, 64.6 seeds.

TABLE 4.25.3. Illegitimate union.

10 flowers fertilised by the mid-length stamens of the long-styled.

0 14 0 0 0 0 0 0 - 0 23

Too sterile for any average.

TABLE 4.25.4. Illegitimate union.

10 flowers fertilised by the longest stamens of the mid-styled.

0 0 0 0 0 0 0 0 - 0 0

Too sterile for any average.

TABLE 4.25.5. Illegitimate union.

10 flowers fertilised by own-form longest stamens.

0 0 0 0 0 0 - 0 0 0 0

Too sterile for any average.

TABLE 4.25.6. Illegitimate union.

10 flowers fertilised by own-form mid-length stamens.

64?* 0 0 0 0 0 - 0 21 0 9

(4/7. *I suspect that by mistake I fertilised this flower in Table 4.25.6 with pollen from the shortest stamens of the long-styled form, and it would then have yielded about 64 seeds. Flowers to be thus fertilised were marked with black silk; those with pollen from the mid-length stamens of the short-styled with black thread; and thus probably the mistake arose.)

Too sterile for any average.

Besides the experiments in the table, I fertilised a number of flowers without particular care with their own two kinds of pollen, but they did not produce a single capsule.

SUMMARY OF THE RESULTS.

LONG-STYLED FORM.

Twenty-six flowers fertilised legitimately by the stamens of corresponding length, borne by the mid-and short-styled forms, yielded 61.5 per cent of capsules, which contained on an average 89.7 seeds.

Twenty-six long-styled flowers fertilised illegitimately by the other stamens of the mid-and short-styled forms yielded only two very poor capsules.

Thirty long-styled flowers fertilised illegitimately by their own-form two sets of stamens yielded only eight very poor capsules; but long-styled flowers fertilised by bees with pollen from their own stamens produced numerous capsules containing on an average 21.5 seeds.

MID-STYLED FORM.

Twenty-four flowers legitimately fertilised by the stamens of corresponding length, borne by the long and short-styled forms, yielded 96 (probably 100) per cent of capsules, which contained (excluding one capsule with 12 seeds) on an average 117.2 seeds.

Fifteen mid-styled flowers fertilised illegitimately by the longest stamens of the short-styled form yielded 93 per cent of capsules, which (excluding four capsules with less than 20 seeds) contained on an average 102.8 seeds.

Thirteen mid-styled flowers fertilised illegitimately by the mid-length stamens of the long-styled form yielded 54 per cent of capsules, which (excluding one with 19 seeds) contained on an average 60.2 seeds.

Twelve mid-styled flowers fertilised illegitimately by their own-form longest stamens yielded 25 per cent of capsules, which (excluding one with 9 seeds) contained on an average 77.5 seeds.

Twelve mid-styled flowers fertilised illegitimately by their own-form shortest stamens yielded not a single capsule.

SHORT-STYLED FORM.

Twenty-five flowers fertilised legitimately by the stamens of corresponding length, borne by the long and mid-styled forms, yielded 72 per cent of capsules, which (excluding one capsule with only 9 seeds) contained on an average 70.8 seeds.

Twenty short-styled flowers fertilised illegitimately by the other stamens of the long and mid-styled forms yielded only two very poor capsules.

Twenty short-styled flowers fertilised illegitimately by their own stamens yielded only two poor (or perhaps three) capsules.

If we take all six legitimate unions together, and all twelve illegitimate unions together, we get the following results: