June, 1905] Packard : Color in a Flower Spider. 85 



stated in a letter from Mr. W. F. Kirby, to whom specimens were 

 submitted ; but that is a larger species with a considerably longer 

 oviscapt in the female. The location of this species in the genus 

 Aplopus is merely tentative, the brachypterous males excluding it from 

 this genus unless the male of micropterus , the type, is proved to be 

 also brachypterous. In that case the species with macropterous males 

 would necessarily take another generic name. 



Class III, ARACHNIDA. 



Order II, ARANEIDA. 



CHANGE OF COLOR AND PROTECTIVE COLORA- 

 TION IN A FLOWER-SPIDER. rMISUMENA 

 VATIA THORELL). 



By Alpheus S. Packard, LL.D., 

 Providence, R. I. 



My attention was called to this interesting subject in the summer of 

 1903, by observing the adaptation or "mimicry" of our common 

 Misumena vatia Thorell {Tlwmisns fartus Hentz) to the hues of the 

 petals of the daisy fleabane (Erigeron anni/i/s) in blossom at Mere- 

 point, Brunswick, Maine, July iS. It was then my impression that 

 this spider was known to change its color, and I suppose that this 

 took place within a short period — a few days at least — but on 

 trying to find mention of such rapid or any other change of color I 

 was unable to meet with any such notices. As for my own experience 

 previous to last year I have only a vague recollection of seeing many 

 years ago on a tree or flower a yellow Misumena. On inquiry of Mr. 

 Nathan Banks, he very kindly called my attention to a brief note by 

 James Angus in the American Naturalist, Vol. XVI, p. 1010, which 

 says: "I suppose you know the little flower spiders, that conceal 

 themselves in the flowers, and seize any unwary insect that may chance 

 to come within their reach. I have generally found them white and 

 yellow. I suspected they changed their color, and by experiment I 

 find that this is so. If I take a white one and put it on a sunflower, 

 it will get quite yellow in from two to three days. I believe they 

 capture almost anything, but they seemed to be partial to the bees. I 



