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. Notwithstanding this fact, and assuming that we have here the whole reason of the existence of the light-emitting power, a study of the firefly's habits compels us to believe that the insect would be just as well off without the power as with it.