When the
leaves were 2 or 3 inches in length, including the foot-stalks, the
seedlings on both sides were equal. In the course of a month or two the
crossed plants began to show a slight superiority over the
self-fertilised, which steadily increased; and the crossed flowered in
all four pots some weeks before, and much more profusely than the
self-fertilised. The two tallest flower-stems on the crossed plants in
each pot were now measured, and the average height of the eight stems
was 9.49 inches. After a considerable interval of time the
self-fertilised plants flowered, and several of their flower-stems (but
I forgot to record how many) were roughly measured, and their average
height was a little under 7.5 inches; so that the flower-stems on the
crossed plants to those on the self-fertilised were at least as 100 to
79. The reason why I did not make more careful measurements of the
self-fertilised plants was, that they looked such poor specimens that I
determined to there them re-potted in larger pots and in the following
year to measure them carefully; but we shall see that this was partly
frustrated by so few flower-stems being then produced.
These plants were left uncovered in the greenhouse; and the twelve
crossed plants produced forty capsules, whilst the twelve
self-fertilised plants produced only five; or as 100 to 12. But this
difference does not give a just idea of the relative fertility of the
two lots.
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