104 A. S. PEARSE 



to remain for a long period of time on a background which might 

 induce color changes. Out of the sixty spiders used only two 

 showed any color changes and in both these cases more than a 

 month elapsed before the skin had turned from yellow to white. 

 Furthermore, McCook ('8g-'93, vol. 2, p. 325) demonstrated that 

 spiders of a single species may show striking color variations in 

 the same habitat. From these facts the conclusion is warranted, 

 that Misumena does not change its colors rapidly nor with 

 enough uniformity to make such changes of importance. This 

 is apparently what McCook believed to be the case. 



If, however, we maintain that the color changes of Misumena 

 are unimportant in relation to protective coloration, we must 

 examine other alternatives with all the more care. McCook 

 says: "We are compelled to the conclusion" that Misumena 

 "sought the flower and settled upon it, either accidentally or by 

 choice." Despite his cautious statement in the sentence quoted, 

 he evidenth^ felt that spiders had some power of color discrim- 

 ination, for he states (vol. 2, p. 367), without unfavorable com- 

 ment, that Mrs. Treat found that Misumena would not stay on 

 a background of a different color from its own, and he also says 

 (p. 335) that the male spider is conscious of the colors of the 

 female. The Peckhams ('87a) had previously shown that spiders 

 showed a preference for certain colors when they w^ere allowed 

 to choose from several on which they might rest, and they 

 state distinctly ('95, p. 261) : " We, ourselves, are of the opinion 

 that all the experiments taken together strongly indicate that 

 spiders have the power of distinguishing colors." They also 

 affirm that certain attids can see small objects distinctly at a 

 distance of at least twelve inches. 



In the light of these observations it might reasonably be 

 expected that Misumena would show a tendency to seek an 

 environment colored like itself, but this w^as not the case, in the 

 writer's experiments. When yellow and white spiders were given 

 an opportunity to choose between white and yellow papers or 

 flowers they did not do so either in the laboratory or in the field ; 

 nor was any difference in the degree of activity on flowers of either 

 color manifest. We are, therefore, forced to conclude that 

 Misumena neither changes color rapidly to match its surround- 

 ings, nor seeks an environment colored like itself. 



It is therefore not within the province of this investigation 



