CHAPTER XIII. 
NATURE'S NIGHT LIGHTS. 
(Remarks about Fireflies and other matters.) 
It was formerly supposed that the light of the fire- 
fly (an any family possessing the luminous power) 
was a safeguard against the attacks of other insects, 
rapacious and nocturnal in their habits. This was 
Kirby 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 lhghts in a 
district abounding with beasts of prey. Notwith- 
