AUTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE AUGUST 6. 



THE RATE OF LOCOMOTION IN VANESSA ANTIOPA IN 

 INTERMITTENT LIGHT AND IN CONTINUOUS 

 LIGHT OF DIFFERENT ILLUMINATIONS, AND ITS 

 BEARING ON THE "CONTINUOUS ACTION THEORY" 

 OF ORIENTATION 



WILLIAM L. DOLLEY, JR. 



From the Biological Lahorafory of Randolph-Macon College, Ashland, Va. 



INTRODUCTION 



Loeb in his interesting ''continuous action theory" of orien- 

 tation maintains that the rate of movement of the locomotor 

 appendages on either side of a bilaterally symmetrical organism 

 which orients depends directly upon the intensity of the stimula- 

 ting agent as it reaches the receptors connected with the ap- 

 pendages. He maintains that if such an organism is not 

 oriented the receptors on one side receive more energy from the 

 source of stimulation than those on the opposite side, and that 

 consequently the locomotor appendages connected with the 

 receptors on this side move faster than those connected with the 

 receptors on the opposite side. If this is true, the butterfly, 

 Vanessa antiopa, which orients and is positive, should move 

 faster in strong than it does in weak light. 



To test this the rate of movement of 19 specimens of Vanessa 

 antiopa was ascertained in different illuminations. Fourteen 

 were tested in each of two lights, one nearly 500,000 times 

 stronger than the other, and 5 were tested in each of two 

 lights, one nearly 1000 times stronger than the other. They 

 did not walk faster in the strong light than in the weak, as the 

 "continuous action theory" demands. On the contrary they 

 tended to walk faster under certain conditions in the weak than 

 they did in the strong light. 



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