Better
evidence could hardly be desired of the immense advantage derived from a
cross with a fresh stock.
26. PRIMULACEAE.--Cyclamen persicum. (6/5. Cyclamen repandum according
to Lecoq 'Geographie Botanique de l'Europe' tome 8 1858 page 150, is
proterandrous, and this I believe to be the case with Cyclamen
persicum.)
Ten flowers crossed with pollen from plants known to be distinct
seedlings, yielded nine capsules, containing on an average 34.2 seeds,
with a maximum of seventy-seven in one. Ten flowers self-fertilised
yielded eight capsules, containing on an average only 13.1 seeds, with a
maximum of twenty-five in one. This gives a ratio of 100 to 38 for the
average number of seeds per capsule for the crossed and self-fertilised
flowers. The flowers hang downwards, and as the stigmas stand close
beneath the anthers, it might have been expected that pollen would have
fallen on them, and that they would have been spontaneously
self-fertilised; but these covered-up plants did not produce a single
capsule. On some other occasions uncovered plants in the same greenhouse
produced plenty of capsules, and I suppose that the flowers had been
visited by bees, which could hardly fail to carry pollen from plant to
plant.
The seeds obtained in the manner just described were placed on sand, and
after germinating were planted in pairs,--three crossed and three
self-fertilised plants on the opposite sides of four pots.
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