Page:The Zoologist, 4th series, vol 1 (1897).djvu/338

310 conclude that, because milk is found in the breast of a new-born babe (a singular fact, best known to every nurse), when it cannot be required to give suck, therefore the same child is not to give suck when she has become a woman, and has children of her own. The light of the Glowworm proceeds from a lantern in the under side of the tail, protected by a transparent skin. The researches of such an anatomist as Swammerdam would probably find a dark shutter or slide between the glass of the lantern and the lamp within, moveable at the pleasure of the insect. If you crush a Glowworm while it is shining, the light will smear about exactly like that of the Centipede. I have never tried the experiment by day, or at times when they do not shine. The Glowworm appears to know, by an unerring instinct, the proper time for it to begin its exhibition, which is shortly after sunset. I have repeatedly kept them all day long in a dark cellar without being able, by the gloom or the coldness, to make them withdraw their curtain; but on returning in the evening, I have found them glittering as brightly as in their native copse. The best way to keep them in confinement is to have a live turf at the bottom of a glass globe. All day long they remain hidden close to the earth, but at the appointed hour of evening they will mount the blades of grass as high as they will bear them, turn up the ends of their tails, and display a splendour more steady and beautiful than either gas or camphine. The duration of their performance is very variable, sometimes not more than half an hour, sometimes till what the Scotch call the 'sma' hours.' Whether this depends upon the weather or the health of the creature, is best known to itself. After a while, also variable, they lay their eggs among the turf, and themselves in the dust, to shine no more. So briefly perish these stars of the earth, in fit contrast with those of heaven, glittering as they do, through ages upon ages, with undimmed and never-tiring lustre."

It is curious that among all the suggestions which have been offered to account for the luminosity of the worm we find no mention of the use of phosphorescence for protection. When the water was agitated, Von Stein's worm became luminous. Was not that protective? The enemy of the Centipede, Glowworm, or annelid would fear the fire, and keep at a respectful