5. Various species of insects visit the flowers for pollen. Many
insects secure pollen without effecting pollination.
6. In a rather hasty microscopic examination, no very apparent
difference was detected between the pollen from large and small stamens.
7. A very important function of the observed arrangement of stamen and
pistil in _S. rostratum_ seems to the writers to be that of support for
the visiting insect.
8. It might seem that the pollen from the small stamens is of much
more importance in the process of fertilization than Professor Todd
suspected, especially since it seems that there is much more certainty
of the pollen from the small stamens reaching the pistil than there is
of that from the large stamen. The fact that there is some question
as to the fertility of the pollen from the large stamen in all cases,
and that in the case of another plant stamens of somewhat similar
arrangement seem to have lost entirely their direct reproductive
function, would indicate the same.
9. In a limited number of cases the pollen from the large stamen of
a flower seems to be fertile on its own stigma, as well as upon the
stigma of a flower opening simultaneously on the opposite side of
raceme.