COLOR AND THE BEHAVIOR OF ARTHROPODS 95 



males were placed in a yellow jar; on December i8, one died 

 and the other was still white on December 31. 



September 22, 1910. Twelve white males and four white 

 females were placed in four yellow jars. None of these Misumenas 

 changed color, though five of the males were alive December 22. 



Experiment 5 was carried out in order to ascertain if light 

 per se has any effect on the colors of Misumena. On September 

 13, 1 910, eight spiders were placed in four glass jars. Two of 

 these jars contained two yellow spiders each, and the other two 

 contained the same number of white individuals. The jars were 

 so placed that half the spiders of each color were in the dark, 

 while the others were exposed to direct sunlight before a window. 

 No change could be observed to have occurred in the colors of 

 any of the spiders on September 24. On October 8, all the white 

 spiders died, also one of the yellow individuals. Light or its 

 absence induced no observable color change during twenty-two 

 da vs. 



From the five experiments described it is apparent that the 

 few color changes which took place were too slow to be of much 

 advantage to a spider in nature. Most of the Misumenas did 

 not change color and those that did would hardly have had 

 tiriie to adapt themselves to a particular flower before it withered. 



(b) The Reactions of Misumena to flowers and colored hack- 

 grounds. As a preliminary step the reactions of Misumena to 

 white light were tested by means of a horizontal beam from a 

 one-glow^er Nernst lamp. During these experiments the lamp 

 was placed at one end of a table and the spiders were allowed 

 to run from a vial on to the table at a distance of forty centi- 

 meters from the source of light. Five reactions for each of five 

 individuals were taken. None of the spiders moved directly 

 toward or away from the light but in every case they went ahead 

 in a rather erratic manner and climbed up, or ran along the edge 

 of the black side screens which were used to cut off their view 

 from objects in the room where the experiments WTre performed. 

 From these results it was assumed that ]\Iisumena's reactions 

 to directive light were negligible so far as their influence on the 

 reaction experiments which followed \^'ere concerned. This con- 

 clusion was supported by the general behavior of spiders in the 

 field and laboratory, no indications of marked reactions to light 

 per se were ever noted. 



