43() 



E. A. ANDREWS 



his legs and finally on the fourth was in copulation/ just as in 

 other beetles, with no possible use of the horns at this period, 

 and though on the fifth the male was again following the retreat- 

 ing female and endeavoring to copulate, there was no observed 

 use of the horns. 



Fig. 1. Photograph of living male Dynastes tityrus, showing form of head 

 and thorax and distribution of dark spots on the elytra. 



While the significance of these male horns thus remains en- 

 tirely problematical, certain color changes in both males and 

 females were definitely established and will be here described. 



Mr. M. G. Gichner in setting about to make photographs of 

 these beetles observed that the color of the beetle might 

 rapidly change, and as such changes, back and forth from one 

 color to another, seem to be unrecorded in any such insect, or 

 in fact in any animal not having changeable pigment cells or 

 blood vessels so disposed as to make a color change possible, 



