Firstly, in the third and fourth generations of Mimulus luteus, a tall
variety, often alluded to, having large white flowers blotched with
crimson, appeared amongst both the intercrossed and self-fertilised
plants. It prevailed in all the later self-fertilised generations to the
exclusion of every other variety, and transmitted its characters
faithfully, but disappeared from the intercrossed plants, owing no doubt
to their characters being repeatedly blended by crossing. The
self-fertilised plants belonging to this variety were not only taller,
but more fertile than the intercrossed plants; though these latter in
the earlier generations were much taller and more fertile than the
self-fertilised plants. Thus in the fifth generation the self-fertilised
plants were to the intercrossed in height as 126 to 100. In the sixth
generation they were likewise much taller and finer plants, but were not
actually measured; they produced capsules compared with those on the
intercrossed plants, in number, as 147 to 100; and the self-fertilised
capsules contained a greater number of seeds. In the seventh generation
the self-fertilised plants were to the crossed in height as 137 to 100;
and twenty flowers on these self-fertilised plants fertilised with their
own pollen yielded nineteen very fine capsules,--a degree of
self-sterility which I have not seen equalled in any other case.
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