at on
the surface of the water to the female ones.[166] Other flowers of the
classes of monoecia and dioecia, and polygamia discharge the
fecundating farina, which, floating in the air, is carried to the stigma
of the female flowers, and that at considerable distances. Can this be
effected by any specific attraction? Or, like the diffusion of the
odorous particles of flowers, is it left to the currents of the winds,
and the accidental miscarriages of it counteracted by the quantity of
its production?

"2. This leads us to a curious inquiry, whether vegetables have ideas of
external things? As all our ideas are originally received by our senses,
the question may be changed to whether vegetables possess any organs of
sense? Certain it is that they possess a sense of heat and cold, another
of moisture and dryness, and another of light and darkness, for they
close their petals occasionally from the presence of cold, moisture, or
darkness. And it has been already shown that these actions cannot be
performed simply from irritation, because cold and darkness are negative
quantities, and on that account sensation, or volition are implied, and
in consequence a sensorium or union of their nerves. So when we go into
the light we contract the iris; not from any stimulus of the light on
the fine muscles of the iris, but from its motions being associated with
the sensation of too much light upon the retina, which could not take
place without a sensorium or centre of union of the nerves of the iris,
with those of vision.[167]

"Besides these organs of sense, which distinguish cold, moisture, and
darkness, the leaves of mimosa, and of dionaea, and of drosera, and the
stamens of many flowers, as of the berbery, and the numerous class of
syngenesia, are sensible to mechanic impact, that is, they possess a
sense of touch, as well as a common sensorium, by the medium of which
their muscles are excited into action. Lastly, in many flowers the
anthers, when mature, approach the stigma, in others the female organ
approaches to the male. In a plant of collinsonia, a branch of which is
now before me, the two yellow stamens are about three-eighths of an inch
high, and diverge from each other at an angle of about fifteen degrees,
the purple style is half an inch high, and in some flowers is now
applied to the stamen on the right hand, and in others to that of the
left; and will, I suppose, change place to-morrow in those, where the
anthers have