REACTIONS OF THE WHIP-TAIL SCORPION TO LIGHT 



BRADLEY M. PATTEN 



From the Laboratory of Histology and Embryology, School of Medicine, Western 



Reserve University 



FOUR FIGURES 



CONTENTS 



Statement of the problem 251 



General characteristics and behavior 252 



Apparatus 255 



Measurements of reactions to light 256 



Discussion 267 



Summary 274 



Literature cited 275 



STATEMENT OF THE PROBLEM 



During the past summer I was fortunate in having an oppor- 

 tunity to work with a number of specimens of the whip-tail 

 scorpion (Mastigoproctus giganteus, Lucas), The fact that this 

 Thelyphonid has median eyes which are well separated anatom- 

 ically from the lateral eyes, made it appear a promising subject 

 for experiments to determine the relative effectiveness of the 

 two types of eyes. 



Since there have been no extensive observations published 

 concerning the effects of light on any of the Thelyphonids, the 

 present paper has been devoted to presenting data on the reac- 

 tions of normal animals. No attempt was made to treat ex- 

 haustively all phases of their behavior under the influence of 

 light. The object was rather to obtain such reaction measure- 

 ments as would best serve as a basis of comparison for subse- 

 quent work directed toward determining the relative effective- 

 ness of the various parts of their photoreceptive mechanism. 



251 



