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228 cocoon thread to the recording lever of an Oscillating Recorder to be fully described in the next Paper. The pulsation continued even in this isolated condition for about 48 hours, after which the. spontaneous movement came. to a stop. Further experiments showed that the arrest of pulsation was not, in licative of mortality but of ‘latent life’ in a state of suspense, to be stirred up again by shock stimulus into throbbing activity.

I'Lrperinn-n/ {ML—In ﬁgure 84, is a seen record of the

I’m. 31. —lteue\\:\l of autonomous activity in Ih'srtlmli'lm ,tl'lm’” ill *limtiﬁlm by at‘tion of light. l'poenru- represents up-nion-nent. The horizontal lints below

represent d nations of t‘\[m~tlre to light.

action of light on the sub-tonic Hesmotlimn lea‘let at standstill. .\ narrow pencil of light from electric arc was ﬁrst thrown on the lamina in which the presence of chlorophyll rendered photo-synthetic action possible. This had no etlect on the renewal of pulsation. But the autonomous activity was revived by the action of light_on the pulvinule. This preferential ell'ect on pulvinule showed that the reneval of activity vas due not to photo-syn- thesis bnt to the stimulating action of light. The pulsa- tion was also restored by chemical stimulants, such as dilute ether, and solution of ammonium carbonate.