438 E, A. ANDREWS 



As stated in text books, the beetles when freshly emerged 

 from the pupa are of a dark chestnut or red color without spots. 

 In our museum we have such a specimen, a female of homogeneous 

 red chestnut color, together with a male of the faded greenish 

 white with black spots as figured and described also in books. 



When the live specimens, that were prevailingly light yellow 

 with dark spots, were put into glass dishes with decayed wood 

 that was wet and were left quiet over night, it was observed 

 that they all had become very dark reddish with spots scarcely 

 discernible, so that the background of yellow had changed to 

 about the same color as the spots had been. 



When these dark males and females were removed for photog- 

 raphy they rapidly returned to the usual light coloration. 



The startling nature of this color change is best seen in the 

 actual specimen where the extremes are very diverse; but to 

 indicate the range of color we may make use of the color code 

 of Paul Klincksieck, Paris, '08. The dark color may be called 

 a red-orange like no. 80 or it may be violet-red like no. 580 or 

 again nearly black. The light color assumed usually may be 

 an orange-yellow like no. 187 or a green-yellow like no. 287 or 

 297 or a yellow-green like nos. 272 or 292 in the female and 

 somewhat more yellow in the male. Owing to the high polish 

 of the surface, the actual color is difficult to determine. The 

 change of color is the more emphatic since the spots on the elytra 

 remain dark when the background bleaches from dark to light. 



The cause of the change of color seemed at first to be com- 

 plex and to involve internal factors of response of the whole 

 animal. Thus, when the beetles were quiet in dark, moist 

 wood, they were dark; when active in dry light places they were 

 light. When taken from the moist wood they very quickly 

 changed to the light coloration, but did not change back to 

 the dark when restored to the more natural environment till 

 after a long time had elapsed, so that it might be that disturb- 

 ance of the nervous system from light and from handling caused 

 the bleaching which might persist till the nervous system had 

 been slowly changed in the apparent sleep of the quiet beetle. 



