RELATIVE WEIGHT AND PERIOD OF GERMINATION OF SEEDS FROM CROSSED AND
SELF-FERTILISED FLOWERS.
An equal number of seeds from flowers fertilised with pollen from
another plant, and from flowers fertilised with their own pollen, were
weighed, but only in sixteen cases. Their relative weights are given in
the following list; that of the seeds from the crossed flowers being
taken as 100.
Column 1: Name of Plant.
Column 2: x, in the expression, 100 to x.
Ipomoea purpurea (parent plants): 127.
Ipomoea purpurea (third generation): 87.
Salvia coccinea: 100.
Brassica oleracea: 103.
Iberis umbellata (second generation): 136.
Delphinium consolida: 45.
Hibiscus africanus: 105.
Tropaeolum minus: 115.
Lathyrus odoratus (about): 100.
Sarothamnus scoparius: 88.
Specularia speculum: 86.
Nemophila insignis: 105.
Borago officinalis: 111.
Cyclamen persicum (about): 50.
Fagopyrum esculentum: 82.
Canna warscewiczi (3 generations): 102.
It is remarkable that in ten out of these sixteen cases the
self-fertilised seeds were either superior or equal to the crossed in
weight; nevertheless, in six out of the ten cases (namely, with Ipomoea,
Salvia, Brassica, Tropaeolum, Lathyrus, and Nemophila) the plants raised
from these self-fertilised seeds were very inferior in height and in
other respects to those raised from the crossed seeds. The superiority
in weight of the self-fertilised seeds in at least six out of the ten
cases, namely, with Brassica, Hibiscus, Tropaeolum, Nemophila, Borago,
and Canna, may be accounted for in part by the self-fertilised capsules
containing fewer seeds; for when a capsule contains only a few seeds,
these will be apt to be better nourished, so as to be heavier, than when
many are contained in the same capsule.
Pages:
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503