perenne, affairs are arranged more perfectly; for the stamens
in the two forms stand at different heights, so that pollen from the anthers of
the longer stamens will adhere to one part of an insect's body, and will
afterwards be brushed off by the rough stigmas of the longer pistils; whilst
pollen from the anthers of the shorter stamens will adhere to a different part
of the insect's body, and will afterwards be brushed off by the stigmas of the
shorter pistils; and this is what is required for the legitimate fertilisation
of both forms. The corolla of L. perenne is more expanded than that of L.
grandiflorum, and the stigmas of the long-styled form do not diverge greatly
from one another; nor do the stamens of either form. Hence insects, especially
rather small ones, will not insert their proboscides between the stigmas of the
long-styled form, nor between the anthers of either form (Figure 3.5), but will
strike against them, at nearly right angles, with the backs of their head or
thorax. Now, in the long-styled flowers, if each stigma did not rotate on its
axis, insects in visiting them would strike their heads against the backs of the
stigmas; as it is, they strike against that surface which is covered with
papillae, with their heads already charged with pollen from the stamens of
corresponding height borne by the flowers of the other form, and legitimate
fertilisation is thus ensured.
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