SEARCH
0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Prev | Current Page 473 | Next

Darwin, Charles, 1809-1882

"Effects of Cross and Self Fertilisation in the Vegetable Kingdom"


These fifty-five flowers produced fifty-two capsules, almost all of
which were of full size and contained an abundance of seeds. On the
other hand, seventy-nine flowers (besides many others not recorded) were
fertilised with pollen from other flowers on the same plants, and these
did not produce a single capsule. In one case in which I examined the
stigmas of the flowers fertilised with their own pollen, these were
penetrated by the pollen-tubes, although such penetration produced no
effect. Pollen falls generally, and I believe always, from the anthers
on the stigmas of the same flower; yet only three out of the above seven
protected plants produced spontaneously any capsules, and these it might
have been thought must have been self-fertilised. There were altogether
seven such capsules; but as they were all seated close to the
artificially crossed flowers, I can hardly doubt that a few grains of
foreign pollen had accidentally fallen on their stigmas. Besides the
above seven plants, four others were kept covered under the SAME large
net; and some of these produced here and there in the most capricious
manner little groups of capsules; and this makes me believe that a bee,
many of which settled on the outside of the net, being attracted by the
odour, had on some one occasion found an entrance, and had intercrossed
a few of the flowers.
In the spring of 1869 four plants raised from fresh seeds were carefully
protected under separate nets; and now the result was widely different
to what it was before.


Pages:
461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485
print 'ubezpieczenia samochodów 1171501696' . "\n"; print 'ubezpieczenie komunikacyjne 1171501697' . "\n"; print 'Moschino 1171501872' . "\n"; print 'hdi oc 1171501671' . "\n"; print 'oleje samochodowe 1171501599' . "\n";