CHAPTER XIII. 



nature's night lights. 



{Remarks about Fireflies and other matters.) 



It was formerly supposed that the light of the fire- 

 fly (in any family possessing the luminous power) 

 was a safeguard against the attacks of other insects, 

 rapacious and nocturnal in their habits. This was 

 Kir by and Spence's notion, but it might just as well 

 be Pliny's for all the attention it would receive from 

 modern entomologists : just at present any ob- 

 server who lived in the pre-Darwin days is regarded 

 as one of the ancients. The reasons given for the 

 notion or theory in the celebrated Introduction to 

 Entomology were not conclusive; nevertheless it 

 was not an improbable supposition of the authors' ; 

 while the theory which has taken its place in recent 

 zoological writings seems in every way even less 

 satisfactory. 



Let us first examine the antiquated theory, as it 

 must now be called. By bringing a raptorial insect 

 and a firefly together, we find that the flashing light 

 of the latter does actually scare away the former, 

 and is therefore, for the moment, a protection as 

 effectual as the camp-fire the traveller lights in a 

 district abounding with beasts of prey. Notwith- 



