ILLUSTRATIONS xix 



FIG. PAGE 



96. RESPONSE OF SENSITIVE CELL TO LIGHT 152 



97. TYPICAL EXPERIMENT ON THE E.M. VARIATION PRODUCED 



BY LIGHT 154 



98. MODIFICATION OF THE PHOTO-SENSITIVE CELL . . . . 155 







99. RESPONSES IN FROG'S RETINA 156 



100. RESPONSES IN SENSITIVE PHOTO-CELL 157 



101. EFFECT OF TEMPERATURE ON THE RESPONSE TO LIGHT 



STIMULUS 159 



102. EFFECT OF DURATION OF EXPOSURE ON THE RESPONSE . . 159 



103. RESPONSES OF SENSITIVE CELL TO INCREASING INTENSITIES 



OF LIGHT 161 



104. RELATION BETWEEN THE INTENSITY OF LIGHT AND MAGNI- 



TUDE OF RESPONSE 162 



105. AFTER-OSCILLATION 163 



106. TRANSIENT POSITIVE INCREASE OF RESPONSE IN THE FROG'S 



RETINA ON THE CESSATION OF LIGHT 164 



107. TRANSIENT POSITIVE INCREASE OF RESPONSE IN THE 



SENSITIVE CELL 165 



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 



ALTERNATION OF VISION 176 



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 



NERVE AND METAL . . . . . . .186 



116. MODIFIED ABNORMAL RESPONSE IN NERVE AND METAL 



TRANSFORMED INTO NORMAL RESPONSE AFTER CONTINUOUS 



STIMULATION 187 



117. ACTION OF THE SAME ' POISON' IN THE ABOLITION OF RE- 



SPONSE IN NERVE, PLANT, AND METAL .... 189 



