PHYSIOLOGIC LIGHT 121 



to from seven to fourteen males seems to be about the proportion. The 

 same condition appears to hold with other species of Lampyridae also. 

 King states that the female of the Texan form Pleotomus pollens 

 is much more luminous, and rather less active than the male. In addi- 

 tion to the photogenic power, the common firefly is possessed of a 

 strong and characteristic odor; Carradori also notes that the Italian 

 luciole has an odor like that of garlic. Many insects indeed possess 

 odors, but that of the Lampyridae appears to be especially character- 

 istic of the group. 



In conclusion, we may say that while a vast amount of work has 

 already been done on this interesting problem, the production of physi- 

 ologic light still presents many mysteries which science has yet to ex- 

 plain. Nature keeps her secrets well, but this one seems well worthy of 

 solution; the immediate practical and economic importance may not 

 be so great as has been sometimes assumed, but it is a problem of in- 

 terest alike for the physicist, the chemist, the biologist and the ento- 

 mologist, and the scientific world awaits its solution with much curi- 

 osity. 



VOL. LXXVII. -9. 



