, 183
by relative depression, 87
by relative exaltation, 89
conditions for obtaining, 6, 86, 87
continuous transformation from positive to negative in metal, 115
decline and reversal of, under continuous light in photo-sensitive
cell, 166
decline and reversal of, under continuous light in retina, 166
depressants, effect of, on inorganic, 142
diminution of. _See_ Fatigue
diphasic
in metal, 113, 114, 115, 116, 188
in nerve, 188
in plant, 46, 188
dose, effect of,
on inorganic, 89, 146, 189
on, in plant, 79, 189
enhancement of, after continuous stimulation in metal, 127, 128, 186
enhancement of, after continuous stimulation in nerve, 127, 186
maximum effect due to superposition of stimulus, 35, 136
measure of physiological activity, 13
molecular
friction, effect of, on, 108, 109
modification, effect of, on, 11, 48, 123, 125, 129, 164, 187
physiological character of, in plant, 30
positive and negative, 11
prolongation of recovery in, by 'poison' in metal, 145
prolongation of recovery in, by 'poison' in muscle, 144
prolongation of recovery in, from overstrain, 106
relation between, and stimulus
in metal, 134, 135
in muscle, 52
in nerve, 52
in plant, 52, 53, 54
in real and artificial retinae, 162
staircase effect,
in metal, 122, 186
in plant, 37, 186
stimulant, effect of, on, in metal, 141
temperature, effect of, on. _See_ Temperature
threshold of, 135
to light. _See_ Light
uniform
in metal, 102, 184
in nerve, 184
in plant, 36, 184
universal applicability of, 12
mechanical, 1
retinal. _See_ Light
simultaneous mechanical and electrical record of, 13

Retina. _See_ Light

Sanderson, Burdon-, on electrical response in sensitive plants, 14

Spring-tapper, mechanical stimulus by, 23

Staircase effect
in metal, 122, 186
in muscle, 122, 186
in plant, 37, 186

Steiner on retinal response, 149

Stimuli, maximum effect due to superposition of,
in metal, 136
in muscle, 36
in plant, 36

Stimulus,
advantages of vibrational, 25
and response, relation between,
in metal, 134, 135
in muscle, 52
in nerve, 52
in plant