CONTENTS. 



Pase. 



Introduction 177 



General survey of changes in shade, color, nnd pattern in fishes 180 



Detailed study of changes in shade, color, and pattern in Paralichihys and Ancylopseiia 182 



Behavior 182 



Adaptive changes in shade, color, and pattern 184 



Natural backgrounds 184 



Black and white background, artificial 1S6 



Relation between the pattern in the skin and that in the background 188 



Individuality of the pattern 190 



Effect of mechanical and other stimuli on the pattern igi 



Colored background, artificial 192 



General statements 192 



Experiments and results in detail 193 



Conclusions 198 



Rate of adaptation to background 198 



Factors involved in the process of adaptation ... 199 



Chromatophores in the skin 199 



Eyes, nervous system, and direct action of stimulating agents as factors in adaptation to 



backgrounds 200 



Extent of distribution of stimuli from either eye 204 



Relation between the intensity of light and the reaction of the chromatophores 205 



Light reflection from the skin as a factor in adaptation 206 



The direction of the light as a factor in adaptation 207 



Experiments (A), light from below relatively stronger than normal 208 



Experiments (B), light from above relatively stronger than normal 212 



Vision 215 



Color-vision ;... 215 



Vision of motion, size, and form 219 



Fusion rate of images on the retina 220 



Summary 221 



Selection of background 222 



Group method 222 



Individual method 223 



Colored backgrounds 224 



Summary 225 



Discussion 227 



Bibliography 230 



Explanation of plates 233 



17s 



