CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORT OP THE BTaSEUM OF COMPARATIVE 

 HARVARD COLLEGE, NO. 272 



THE MOVEMENTS IN THE VISUAL CELLS AND 



RETINAL PIGMENT OF THE LOWER 



VERTEBRATES 



LESLIE B. AREY 

 Northwestern University Medical School 



ONE TEXT FIGURE AND FIVE PLATES 



CONTENTS 



L Introduction and historical review 121 



2. Material and technique 124 



3. Experimental part 126 



A. Determination of adaption times 126 



(a.) Retinal i)i{iment 127 



(b) Visual cells 129 



B. Effect of temperature (normal animals) 133 



(a) Retinal pigment 133 



(b) Visual cells , 151 



C. Experimentation upon excised eyes 163 



(a) Effect of light and darkness 163 



(b) Effect of temperature 168 



D. Effect of anaesthetics. 171 



(a) Retinal pigment 172 



(b) Visual cells 175 



E. Effect of oxygen 176 



F. Interrelation of integumentary jihotoreceptors and retinal elements. 179 



4. Discussion ■ 181 



5. Summary . 184 



Bibliography 1S8 



1. INTRODUCTION AND HISTORICAL REVIEW 



The positional changes that occur in t'he vertebrate retina 

 chiefly through the action of hght have attracted the attention 

 of many workers in continental Europe although, strangely 

 enough, neither English nor American investigators have hither- 

 to concerned themselves with this particular field of endeavor. 

 The results acquired from these researches have proved of such 

 interest and significance as to equal, and perhaps even to sur- 



121 



THE JOURNAL OP COMPAR.VTIVE NEUROLOGY, VOL. 26, NO. 2 

 APRIL, 1916 



