The pots were then bedded out, and the
roots probably came out of the holes at the bottom and thus aided their
growth. Early in the following summer the superiority of the crossed
plants, owing to their increase by stolons, over the self-fertilised
plants was truly wonderful. In Pot 1, and it should be remembered that
very large pots had been used, the oval clump of crossed plants was 10
by 4 1/2 inches across, with the tallest stem, as yet young, 5 1/2
inches in height; whilst the clump of self-fertilised plants, on the
opposite side of the same pot, was only 3 1/2 by 2 1/2 inches across,
with the tallest young stem 4 inches in height. In Pot 2, the clump of
crossed plants was 18 by 9 inches across, with the tallest young stem 8
1/2 inches in height; whilst the clump of self-fertilised plants on the
opposite side of the same pot was 12 by 4 1/2 inches across, with the
tallest young stem 6 inches in height. The crossed plants during this
season, as during the last, flowered first. Both the crossed and
self-fertilised plants being left freely exposed to the visits of bees,
manifestly produced much more seed than their grand-parents,--the plants
of the original clump still growing close by in the same garden, and
equally left to the action of the bees.
5. ACANTHACEAE.--Thunbergia alata.
It appears from Hildebrand's description ('Botanische Zeitung' 1867 page
285) that the conspicuous flowers of this plant are adapted for
cross-fertilisation.
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