The plants were measured when in full flower. Table 5/66,
therefore, includes plants belonging to two generations. When the
seedlings of the two lots were only 5 or 6 inches in height they were
equal. In Pot 3 one of the self-fertilised plants died before flowering,
as has occurred in so many other cases.
TABLE 5/66. Lactuca sativa.
Heights of plants measured in inches.
Column 1: Number (Name) of Pot.
Column 2: Crossed Plants.
Column 3: Self-fertilised Plants.
Pot 1 : 27 : 21 4/8.
Pot 1 : 25 : 20.
First generation, planted in open ground.
Pot 2 : 29 4/8 : 24.
Pot 2 : 17 4/8 : 10.
Pot 2 : 12 4/8 : 11.
Second generation, planted in open ground.
Pot 3 : 14 : 9 4/8.
Pot 3 : 10 4/8 : 0.
Second generation, kept in the pot.
Total : 136 : 96.
The average height of the seven crossed plants is 19.43, and that of the
six self-fertilised plants 16 inches; or as 100 to 82.
21. CAMPANULACEAE.--Specularia speculum.
In the closely allied genus, Campanula, in which Specularia was formerly
included, the anthers shed at an early period their pollen, and this
adheres to the collecting hairs which surround the pistil beneath the
stigma; so that without some mechanical aid the flowers cannot be
fertilised. For instance, I covered up a plant of Campanula carpathica,
and it did not produce a single capsule, whilst the surrounding
uncovered plants seeded profusely.
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