[65]

X that no hairs were touched, caused all the hairs & the edges of the leaf leaves itself to become in five hours inflected, in what may be called a senseless manner just as if an fly object had been placed on the front of the upper surface of the leaf; but the leaves in a more sensible manner soon reexpanded when they found nothing to catch, notwithstanding that the flies remained sticking to their backs. (B) From these above facts we see that the heads of the central & marginal hairs, as well as the surfc inferi superior & inferior surface of the leaf itself are all sensitive the (a) The footstalk of the leaf is not sensitive; for I drove pins through it both near the roots & near the leaf, & no effect was produced.— Exposure of a plant, under an inverted tumbler, for only 30 seconds to the vapour of a small quantity of

[in margin:] Result of slight weight

[65v]

(a)

to very slight pressures. For it was most remarkable how minute an atom, less than pin a small pin's head, of porous cinder placed on the disc of the leaf caused the movement. The body of an very extremely minute fly likewise caused the movement; but in this case, as we shall presently see; it is not possible to discriminate the effect of the animalised matter. It is necessary that the pressure extremely slight as it is, should be prolonged, for a mere touch, though rather rough, causes no movement.—