Page:Researches on Irritability of Plants.djvu/149

126 results that were invariably concordant. I content myself, however, with giving two records in each case, obtained from different specimens. In order to test still further the reliability of these results I was careful, with each pair of figures given for comparison, to employ two different recorders, the vibration-frequency of the first being 100, and of the second or companion-set 50 per second.

In fig. 75, with vibrating recorder of 100, are given two records testing the effect of intensity of stimulus on the latent period. The lower of the two was obtained with the minimum stimulus of 1; and the latent period is seen to be .155 second. In the upper of the two records we

have the result of the maximal stimulus of 5. The latent period is now found to be reduced to .1 second.

In fig. 76, with vibrating recorder of 50 and taking a different specimen, we find a precisely similar result. The lower of the two records, with the minimal stimulus of 1, shows a latent period of .14 second. The upper, with stimulus 2, which in this individual case was maximal, shows a latent period of .09 second.

It is interesting to note alike in figs. 75 and 76 the great vigour of the responsive movement under higher intensity of stimulus, as seen in the abruptness of the rise of the curve and the wider spacing of the successive dots.