It is a more remarkable fact that the self-fertilised
plants of the sixth generation had become much more fertile than the
intercrossed plants, judging by the number of capsules spontaneously
produced, in the ratio of 147 to 100. This variety, which as we have
seen appeared amongst the plants of the fourth self-fertilised
generation, resembles in almost all its constitutional peculiarities the
variety called Hero which appeared in the sixth self-fertilised
generation of Ipomoea. No other such case, with the partial exception of
that of Nicotiana, occurred in my experiments, carried on during eleven
years.
Two plants of this variety of Mimulus, belonging to the sixth
self-fertilised generation, and growing in separate pots, were
intercrossed; and some flowers on the same plants were again
self-fertilised. From the seeds thus obtained, plants derived from a
cross between the self-fertilised plants, and others of the seventh
self-fertilised generation, were raised. But this cross did not do the
least good, the intercrossed plants being inferior in height to the
self-fertilised, in the ratio of 100 to 110. This case is exactly
parallel with that given under Ipomoea, of the grandchildren of Hero,
and apparently of its great-grandchildren; for the seedlings raised by
intercrossing these plants were not in any way superior to those of the
corresponding generation raised from the self-fertilised flowers.
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