The phenomena of tactism and tropism may also be partly explained by the action of these diffusion currents of particles in suspension, these polar attractions and repulsions.
We shall in the succeeding series of papers deal with the subject of tropism in general.
We speak of tropism when the organ takes up a resting position definitely related to the effective stimulus.
I was grieved by their tale of sorrow; but it did not surprise me, as I had met with too many proofs of the debasing tendency of theatrical amusements, to be astonished by such a narrative.
A profound study of the motions of the Infusoria and a very penetrating criticism of the idea of tropism have been made recently by Jennings (Contributions to the Study of the Behavior of Lower Organisms, Washington, 1904).
A psycho-tropism here is mechanically to take pen in hand and mechanically write that fishes found on the ground after a heavy rainfall came from overflowing streams.
Nevertheless this is the psycho-tropism of science to all "thunderstones" said to have fallen luminously.
His psycho-tropism was to respond to all reports of carbonaceous matter falling from the sky, by saying that this damned matter had been deposited upon things of the chosen by impact with this earth.
The object of the tropism is to keep the males and females in the nest until swarming time, and then to get them out.
It would, therefore, be a misconception to speak of tropism as of reflexes, since tropisms are reactions of the organism as a whole, while reflexes are reactions of isolated segments.
For the mathematician and the engineer, the “tropism theory of animal conduct,” founded by Dr.
