Page:Life Movements in Plants.djvu/263



In the preceling Paper I have shown the essentia simi arity of effect of stimulus on autonomous ativity of the Desmod leatlet, and of the growing organ how stimulus revived the pulsatory ativity of Desminliun leaflet in l state of stanlstill, in the sam way as it newe the arrsted growth-activity t was shown

The investigation of this subject was renderd porsilble by the successful device of my Oscillating Recorder ight glass fibre was usd for the construction of the lever which was supported on jewel bearings. T'he short arm of A very 2 cm. in length, and the long ar 8 the lever was This gave a magnificalion of 4 times. to increase the magnification to 10 limes or more

The pull exerted by the pulsating lealet is ectremely slight, and the relatively heavy lever made of steel wire us n th Resonant Recorder is not well-suited for our The ulsan of the leaflet is relatively sow purpose being once in two minutes or so of ten tmes a second, given by the Resonant Recorder is therefore too quick. In the Oscillating Recorder tie in- The ntermittent contact termittence was, therefore, reduced to once in a second, or onc in five sconds, the recording plat itself being male to move to-and-fro at this rate. The carrier of the plate holder slides backwarls and forwards ou ball bearings; a