you have attended particularly to Melastoma; if you
have not, perhaps Hooker or Oliver may have done so. I should be very
grateful for any information, as it will guide future experiments.

P.S.--Do you happen to know, when there are only four stamens, whether
it is the petal or sepal-facers which are preserved? and whether in the
four-stamened forms the pistil is rectangularly bent or is straight?

LETTER 621. TO ASA GRAY. Down, February 16th [1862?].

I have been trying a few experiments on Melastomads; and they seem to
indicate that the pollen of the two curious sets of anthers (i.e. the
petal-facers and the sepal-facers) have very different powers; and it
does not seem that the difference is connected with any tendency to
abortion in the one set. Now I think I can understand the structure of
the flower and means of fertilisation, if there be two forms,--one with
the pistil bent rectangularly out of the flower, and the other with it
nearly straight.

Our hot-house and green-house plants have probably all descended by
cuttings from a single plant of each species; so I can make out nothing
from them. I applied in vain to Bentham and Hooker; but Oliver picked
out some sentences from Naudin, which seem to indicate differences in
the position of the pistil.

I see that Rhexia grows in Massachusetts; and I suppose has two
different sets of stamens. Now, if in your power, would you observe the
position of the pistil in different plants, in lately opened flowers
of the same age? (I specify this because in Monochaetum I find great
changes of position in the pistils and stamens, as flower gets old).
Supposing that my prophecy should turn out right, please observe whether
in both forms the passage into the flower is not [on] the upper side
of the pistil, owing to the basal part of the pistil lying close to the
ring of filaments on the under side of the flower. Also I should like to
know the colour of the two sets of anthers. This would take you only a
few minutes, and is the only way I see that I can find out whether these
plants are dimorphic in this peculiar way--i.e., only in the position
of the pistil (621/1. In Exacum and in Saintpaulia the flowers are
dimorphic in this sense: the style projects to either the right or the
left side of the corolla, from which it follows that a right-handed
flower would fertilise a left-handed one, and vice versa. See Willis,
"Flowering Plants and Ferns," 1897, Volume I., page 73.) and