Page:The Zoologist, 4th series, vol 1 (1897).djvu/337

Rh the 'Gardeners' Chronicle' of January 9th, 1847, some very interesting remarks by Mr. J. Wighton on insect luminosity, seeing that many cases of phosphorescence attributed to worms really come under this head. He says:—

"The Centipede (Scolopendra electrica, L.) is one of the few luminous insects met with in this country. Its specific name electrica seems to be a misnomer; lucifera or phosphorifera would be more applicable. It would take a large number of Centipedes to give a sensible shock, even supposing the creature capable of doing so at all. In other electric animals, as the Torpedo, no flash appears, even when they give a discharge strong enough to stun a horse; still less do they shine with the steady light of the Centipede or the Glowworm. The luminosity of the Scolopendra electrica appears to proceed from a clammy slime exuded from the body of the insect, which is analogous to the phosphoric mucus that comes from the skin of certain fishes in an early state of decomposition. Like that, it may be removed from the surface from which it proceeded, and objects smeared with it become luminous. Walking one damp night on a dark road, I picked up something shining from the ground; I screwed it up in paper, and took it home. On unfolding the paper a Centipede crawled out and escaped, leaving its phosphoric slime adhering to the paper. It is doubtful for what purpose this secretion is given to the insect. It can hardly be to attract the opposite sex, as its habits are mostly subterranean, appearing to feed on dry halfdecayed roots and leaves, and in no way injurious to living vegetation, but probably beneficial by admitting air into the soil, and preparing dead organic matter to be more quickly suited for the food of plants. Some mention that it is carnivorous, feeds on small insects, and like the Lithobius forcipatus, or 'Fifty-foot,' of which it is said that it wounds its prey with a venomous fluid emitted from its claws, but I think this cannot be relied on. Indeed it is difficult to do more than guess at the final causes of many curious phenomena among animated beings. One author (De Geer) says that it is by no means certain that the light of the Glowworm is given it for the purpose of inviting the male, because he has proved that the female insect can shine in its infant state, in that of larva, and even after it has taken the form of nymph. But the same sort of reasoning would lead us to Zool. 4th ser. vol. I., July, 1897.