CONTENTS 
CHAPTER I 
THE MECHANICAL RESPONSE OF LIVING SUBSTANCES 
PAGE 
Mechanical response—Different kinds of stimuli—Myograph—Charac- 
teristics of response-curve: period, amplitude, form—Modification 
of response-curves 2 : : - ; : : : i) 
CHAPTER II 
ELECTRIC RESPONSE 
Conditions for obtaining electric response—Method of injury—Current 
of injury—Injured end, cuproid: uninjured, zincoid—Current of 
response in nerve from more excited to less excited—Difficulties 
of present nomenclature—Electric recorder—Two types of response, 
positive and negative—Universal applicability of electric mode of 
response—Electric response a measure of physiological activity— 
Electric response in plants. ; : ; : : : : 5 
CHAPTER III 
ELECTRIC RESPONSE IN PLANTS—METHOD OF NEGATIVE 
VARIATION 
Negative variation — Response recorder — Photographic recorder— 
Compensator— Means of graduating intensity of stimulus—Spring- 
tapper and torsional vibrator—Intensity of stimulus dependent 
on amplitude of vibration—Effectiveness of stimulus dependent on 
rapidity also. : : : : . ; , : : at ae 
