EABTHWORM STUDIES. 309 



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 half- 

 decayed 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. ' z 



