4 good and bad seeds; whilst only 15 per cent of the flowers
fertilised in an illegitimate manner yielded capsules, these containing on an
average only 11.0 good and bad seeds.
In a previous part of this chapter it was shown that illegitimate crosses
between the long-styled form of the primrose and the long-styled cowslip, and
between the short-styled primrose and short-styled cowslip, are more sterile
than legitimate crosses between these two species; and we now see that the same
rule holds good almost invariably with their hybrid offspring, whether these are
crossed inter se, or with either parent-species; so that in this particular
case, but not as we shall presently see in other cases, the same rule prevails
with the pure unions between the two forms of the same heterostyled species,
with crosses between two distinct heterostyled species, and with their hybrid
offspring.
Seeds from the long-styled oxlip fertilised by its own pollen were sown, and
three long-styled plants raised. The first of these was identical in every
character with its parent. The second bore rather smaller flowers, of a paler
colour, almost like those of the primrose; the scapes were at first single-
flowered, but later in the season a tall thick scape, bearing many flowers, like
that of the parent oxlip, was thrown up. The third plant likewise produced at
first only single-flowered scapes, with the flowers rather small and of a darker
yellow; but it perished early.
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