) The result was that 289 of these 520 flowers yielded no seed, or
none that germinated; the seed of 29 flowers produced hybrids, such as
might have been expected from the nature of the pollen employed; and
lastly, the seed of the remaining 202 flowers produced perfectly pure
plants, so that these flowers must have been fertilised by pollen
brought by insects from a distance of between 500 and 600 yards. (10/17.
Henschel's experiments quoted by Gartner 'Kenntniss' etc. page 574,
which are worthless in all other respects, likewise show how largely
flowers are intercrossed by insects. He castrated many flowers on
thirty-seven species, belonging to twenty-two genera, and put on their
stigmas either no pollen, or pollen from distinct genera, yet they all
seeded, and all the seedlings raised from them were of course pure.) It
is of course possible that some of these 202 flowers might have been
fertilised by pollen left accidentally in them when they were castrated;
but to show how improbable this is, I may add that Gartner, during the
next eighteen years, castrated no less than 8042 flowers and hybridised
them in a closed room; and the seeds from only seventy of these, that is
considerably less than 1 per cent, produced pure or unhybridised
offspring. (10/18. 'Kenntniss' etc. pages 555, 576.)
From the various facts now given, it is evident that most flowers are
adapted in an admirable manner for cross-fertilisation.
Pages:
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541