obliterate the effects of pollen from the same form, even when this has been
placed on the stigma a considerable time before. To test this belief, I placed
on several stigmas of a long-styled cowslip plenty of pollen from the same
plant, and after twenty-four hours added some from a short-styled dark-red
Polyanthus, which is a variety of the cowslip. From the flowers thus treated 30
seedlings were raised, and all these, without exception, bore reddish flowers;
so that the effect of pollen from the same form, though placed on the stigmas
twenty-four hours previously, was quite destroyed by that of pollen from a plant
belonging to the other form.

Finally, I may remark that of the four kinds of unions, that of the short-styled
illegitimately fertilised with its own-form pollen seems to be the most sterile
of all, as judged by the average number of seeds, which the capsules contained.
A smaller proportion, also, of these seeds than of the others germinated, and
they germinated more slowly. The sterility of this union is the more remarkable,
as it has already been shown that the short-styled plants yield a larger number
of seeds than the long-styled, when both forms are fertilised, either naturally
or artificially, in a legitimate manner.

In a future chapter, when I treat of the offspring from heterostyled dimorphic
and trimorphic plants illegitimately fertilised with their own-form pollen, I
shall have occasion to show that with the present species and several others,
equal-styled varieties sometimes appear.

Primula elatior, Jacq.
Bardfield oxlip of English authors.

This plant, as well as the last or cowslip (P. veris, vel officinalis), and the
primrose (P. vulgaris, vel acaulis) have been considered by some botanists as
varieties of the same species. But they are all three undoubtedly distinct, as