1^065 

 667S 



5876 



,5015 

 ,492Z 



,4713 



A47Z 

 .4389 



.4121 

 ,4026 



.3889 



Fig. 4. — Spectrum of fluorescent substance found in fireflies below (2) and of firefly lumines- 

 cence above (2) compared with helium vacuum tube (1) {after Coblentz). 



