(1) at the 'make' of a current of moderate intensity a contraction takes place at the cathode; the anode induces no such contractile effect; (2) at the 'make' of a stronger current both the anode and cathode induce contraction. [6] "Irritability of Plants," p. 212. I have also carried out further investigations on the polar effect of current on the autonomous activity of the leaflet of _Desmodium gyrans_. These rhythmic pulsations can be recorded by my Oscillating Recorder. Each pulsation consists of a sudden contractile movement downwards, corresponding to the systole of a beating heart, and a slower up movement of diastolic expansion. Application of cathode at the pulvinule was found to exert a _contractile_ reaction, exhibited either by the reduction of normal limit of diastolic expansion, or by an arrest of movement at systole. The effect of anode was precisely the opposite; the induced _expansion_ was exhibited either by reduction of normal limit of systolic contraction, or by arrest of pulsation at diastole. From the above results it is seen that with a feeble current: (1) contraction is induced at the cathode, and (2) expansion is brought about at the anode. These effects take place under the action of a feeble current. Under strong currents, contraction takes place both at the anode and the cathode. POLAR EFFECT OF ELECTRICAL CURRENT ON GROWTH. The object of this investigation was to determine whether anode and cathode exerted similar discriminative and opposite effects on growth. For this experiment I took a specimen of _Kysoor_ and determined the region where growth was maximum. A piece of moist cloth was wrapped round this region to serve as one of the two electrodes. The second electrode was placed in the neighbouring indifferent region where there had been a cessation of growth. _Effect of Cathode: Experiment 111._--The particular specimen of _Kysoor_ had a normal rate of growth of 0·48 µ per second. On application of the cathode the rate was reduced to 0·14 µ per second, or to less than a third. This will be seen in record (Fig. 107), where N is the normal rate of growth and K, retarded rate under the action of the cathode. [Illustration: FIG. 107.--Retardation of rate of growth under the action of cathode (_Kysoor_).] [Illustration: FIG. 108.--Acceleration of rate of growth under anode (_Kysoor_).]