, with a pink mouth to the corolla).--Fifty
pods, of which only a very few were empty, on a covered-up plant
contained 20 grains weight of seed; so that this variety seems to be
much more self-fertile than the previous one. With Dr. W. Ogle ('Popular
Science Review' January 1870 page 52) a plant of this species was much
more sterile when protected from insects than with me, for it produced
only two small capsules. As showing the efficiency of bees, I may add
that Mr. Crocker castrated some young flowers and left them uncovered;
and these produced as many seeds as the unmutilated flowers.
Antirrhinum majus (peloric var.).--This variety is quite fertile when
artificially fertilised with its own pollen, but is utterly sterile when
left to itself and uncovered, as humble-bees cannot crawl into the
narrow tubular flowers.
Verbascum phoeniceum (Scrophulariaceae).--Quite sterile. See my account
of self-sterile plants.
Verbascum nigrum.--Quite sterile. See my account of self-sterile plants.
Campanula carpathica (Lobeliaceae).--Quite sterile.
Lobelia ramosa (Lobeliaceae).--Quite sterile.
Lobelia fulgens.--This plant is never visited in my garden by bees, and
is quite sterile; but in a nursery-garden at a few miles' distance I saw
humble-bees visiting the flowers, and they produced some capsules.
Isotoma (a white-flowered var.) (Lobeliaceae).--Five plants left
unprotected in my greenhouse produced twenty-four fine capsules,
containing altogether 12.
Pages:
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518