Page:Researches on Irritability of Plants.djvu/150

The following table shows the effect of intensity of stimulus on the latent period:—

Table 1.—Effect of Intensity of Stimulus on Latent Period.

Number.			Intensity of Stimulus.	Latent period.
1	..	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	1 5	.155 .10
2	..	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	1 2	.14 .09
3	..	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	1 4	.15 .11

Fig. 77.—Constancy of latent period when stimulus is above maximal. Lower record under stimulus 2; upper record under stimulus 5. Recorder 100 D.V.

It is thus seen that with the increase of the intensity of stimulus there is a corresponding reduction of the latent period. But it would appear from further experiments that a limit is soon reached, when the stimulus begins to be maximal. A further increase of the intensity of stimulation above this point will have little or no effect in reducing the latent period. This is shown in fig. 77, which gives a pair of records taken with a vibrator having