| → the same thing 1869 1872 |
| something analogous 1866 |
|
| → instance, the mid-styled form of Lythrum salicaria was illegitimately fertilised with the greatest ease by pollen from the longer stamens of the short-styled 1869 1872 |
| a short-styled cowslip yields more seed when fertilised by the long-styled 1866 |
|
| → yielded many seeds; but the latter form did not yield a single 1869 1872 |
| less 1866 |
|
| → the longer stamens of the mid-styled form. 1869 1872 |
| its own form, than does a long-styled cowslip when fertilised in the two corresponding methods. 1866 |
|
| → and in others which might have been adduced, the 1869 |
| the 1866 |
| and in others which might be added, the 1872 |
|
|
the degree of sterility in the latter case depends in an eminent degree on the conditions of life being more or less favourable, so I have found it with illegitimate unions. It is well known that if pollen of a distinct species be placed on the stigma of a flower, and its own pollen be afterwards, even after a considerable interval of time, placed on the same stigma, its action is so strongly prepotent that it generally annihilates the effect of the foreign pollen; so it is with the pollen of the several forms of the same species, for legitimate pollen is strongly prepotent over illegitimate pollen, when both are placed on the same stigma. I ascertained this by fertilising several flowers, first illegitimately, and twenty-four hours afterwards legitimately, with pollen taken from a peculiarly coloured variety, and all the seedlings were similarly coloured; this shows that the legitimate pollen, though applied twenty-four hours subsequently, had wholly destroyed or prevented the action of the previously applied illegitimate pollen. Again, as in making reciprocal crosses between the same two species, there is occasionally a great difference in the result, so
→the same thing
occurs with
plants; for
→instance, the mid-styled form of Lythrum salicaria was illegitimately fertilised with the greatest ease by pollen from the longer stamens of the short-styled
form, and
→yielded many seeds; but the latter form did not yield a single
seed when fertilised by
→the longer stamens of the mid-styled form.
|
|
| In all these
→and in others which might have been adduced, the
forms of the same undoubted species when illegitimately united behave in exactly the same manner as do two distinct species when crossed. This led me carefully to observe during four years many seedlings, raised from several illegitimate unions. The chief result is that these illegitimate plants, as they
|
