Thirty of their flowers were fertilised with
their own pollen and yielded 17 capsules, containing on an average no less than
32, mostly fine seeds. It appears, therefore, that the fertility of these plants
of the fourth illegitimate generation, as long as they were kept under highly
favourable conditions, had not decreased, but had rather increased. The result,
however, was widely different when they were planted out of doors in good soil,
where other cowslips grew vigorously and were completely fertile; for these
illegitimate plants now became much dwarfed in stature and extremely sterile,
notwithstanding that they were exposed to the visits of insects, and must have
been legitimately fertilised by the surrounding legitimate plants. A whole row
of these plants of the fourth illegitimate generation, thus freely exposed and
legitimately fertilised, produced only 3 capsules, containing on an average only
17 seeds. During the ensuing winter almost all these plants died, and the few
survivors were miserably unhealthy, whilst the surrounding legitimate plants
were not in the least injured.
The seeds from the great-great-grandchildren were sown, and 8 long-styled and 2
short-styled plants of the fifth illegitimate generation raised. These whilst
still in the greenhouse produced smaller leaves and shorter flower-stalks than
some legitimate plants with which they grew in competition; but it should be
observed that the latter were the product of a cross with a fresh stock,--a
circumstance which by itself would have added much to their vigour.
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