bees would thus produce a multitude of hybrids between distinct species;
for if a plant's own pollen and that from another species are placed
on the same stigma, the former is so prepotent that it invariably and
completely destroys, as has been shown by Gartner, the influence of the
foreign pollen.

When the stamens of a flower suddenly spring towards the pistil, or
slowly move one after the other towards it, the contrivance seems
adapted solely to ensure self-fertilisation; and no doubt it is useful
for this end: but the agency of insects is often required to cause the
stamens to spring forward, as Kolreuter has shown to be the case with
the barberry; and in this very genus, which seems to have a special
contrivance for self-fertilisation, it is well known that, if
closely-allied forms or varieties are planted near each other, it is
hardly possible to raise pure seedlings, so largely do they naturally
cross. In numerous other cases, far from self-fertilisation being
favoured, there are special contrivances which effectually prevent the
stigma receiving pollen from its own flower, as I could show from the
works of Sprengel and others, as well as from my own observations: for
instance, in Lobelia fulgens, there is a really beautiful and elaborate
contrivance by which all the infinitely numerous pollen-granules are
swept out of the conjoined anthers of each flower, before the stigma of
that individual flower is ready to receive them; and as this flower is
never visited, at least in my garden, by insects, it never sets a seed,
though by placing pollen from one flower on the stigma of another, I
raise plenty of seedlings. Another species of Lobelia, which is visited
by bees, seeds freely in my garden. In very many other cases, though
there is no special mechanical contrivance to prevent the stigma
receiving pollen from the same flower, yet, as Sprengel, and more
recently Hildebrand and others have shown, and as I can confirm, either
the anthers burst before the stigma is ready for fertilisation, or the
stigma is ready before the pollen of that flower is ready, so that
these so-named dichogamous plants have in fact separated sexes, and
must habitually be crossed. So it is with the reciprocally dimorphic and
trimorphic plants previously alluded to. How strange are these facts!
How strange that the pollen and stigmatic surface of the same flower,
though placed so close together, as if for the very purpose of
self-fertilisation