105. AFTER-OSCILLATION 163 106. TRANSIENT POSITIVE INCREASE OF RESPONSE IN THE 164 FROG'S RETINA ON THE CESSATION OF LIGHT 107. TRANSIENT POSITIVE INCREASE OF RESPONSE IN THE 165 SENSITIVE CELL 108. DECLINE UNDER THE CONTINUOUS ACTION OF LIGHT 166 109. CERTAIN AFTER-EFFECTS OF LIGHT 168 110. AFTER-EFFECT OF LIGHT OF SHORT DURATION 172 111. STEREOSCOPIC DESIGN FOR THE EXHIBITION OF BINOCULAR 176 ALTERNATION OF VISION 112. UNIFORM RESPONSES IN NERVE, PLANT, AND METAL 184 113. FATIGUE IN MUSCLE, PLANT, AND METAL 185 114. 'STAIRCASE' EFFECT IN MUSCLE, PLANT, AND METAL 186 115. INCREASE OF RESPONSE AFTER CONTINUOUS STIMULATION IN 186 NERVE AND METAL 116. MODIFIED ABNORMAL RESPONSE IN NERVE AND METAL 187 TRANSFORMED INTO NORMAL RESPONSE AFTER CONTINUOUS STIMULATION 117. ACTION OF THE SAME 'POISON' IN THE ABOLITION OF 189 RESPONSE IN NERVE, PLANT, AND METAL RESPONSE IN THE LIVING AND NON-LIVING CHAPTER I THE MECHANICAL RESPONSE OF LIVING SUBSTANCES Mechanical response--Different kinds of stimuli--Myograph--Characteristics of response-curve: period, amplitude, form--Modification of response-curves. One of the most striking effects of external disturbance on certain types of living substance is a visible change of form. Thus, a piece of muscle when pinched contracts. The external disturbance which produced this change is called the stimulus. The body which is thus capable of responding is said to be irritable or excitable. A stimulus thus produces a state of excitability which may sometimes be expressed by change of form.