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induction shock which is easily graduated By the use of the well known sliding induction coil, in which the approach of the secondary to the primary coil, indicated by the higher reading of the scale, gives rise to increasing intensity of stimulus. The retarding effect of electrical stimulus on growth has already been demon- strated in record taken on a moving plate (Fig, 61),

i shall adopt for unit stimulus, that, intensity of electric shock which induces a barely perceptible sensation in a human being. It is Vt‘l'y interestingr to find, as stated

before, that growth is often affected by an electric stimulus, which is below ilw range of human perception.

Iqll'l’b‘t of lnlmsily: lair/W'iumil, 74.-——I shall now de- .‘H'I‘llH' a typical experiment on the died of intensity of

ilk. .-.-.—l.ilui.~ nf cimmml ~tnnulus of increasing intensities: of 0'20 unit,

l and. and 3 units. Sheri (lashes mwescm ﬂu, moments of application of stimulus.