on the present species; and these are shown in a condensed form in Table 1.11.
Besides using for the illegitimate unions pollen from a distinct plant of the
same form, as was always done by me, he tried, in addition, the effects of the
plant's own pollen. He counted the seeds.

It is remarkable that here all the flowers which were fertilised legitimately,
as well as those fertilised illegitimately with pollen from a distinct plant
belonging to the same form, yielded capsules; and from this fact it might be
inferred that the two forms were reciprocally much more fertile in his case than
in mine. But his illegitimately fertilised capsules from both forms contained
fewer seeds relatively to the legitimately fertilised capsules than in my
experiments; for the ratio in his case is as 42 to 100, instead of, as in mine,
as 53 to 100. Fertility is a very variable element with most plants, being
determined by the conditions to which they are subjected, of which fact I have
observed striking instances with the present species; and this may account for
the difference between my results and those of Hildebrand. His plants were kept
in a room, and perhaps were grown in too small pots or under some other
unfavourable conditions, for his capsules in almost every case contained a
smaller number of seeds than mine, as may be seen by comparing the right hand
columns in Tables 1.10 and 1.11.

The most interesting point in Hildebrand's experiments is the difference in the
effects of illegitimate fertilisation with a flower's own pollen, and with that
from a distinct plant of the same form. In the latter case all the flowers
produced capsules, whilst only 67 out of 100 of those fertilised with their own
pollen produced capsules. The self-fertilised capsules also contained seeds, as
compared with capsules from flowers fertilised with pollen from a distinct plant
of the same form, in the ratio of 72 to 100.

In order to ascertain how far the present species was spontaneously self-