134 INSECTS AT HOME. 



seems unable or unwilling to retain it. Gilbert White, in hia 

 ' Selborne,' remarks that the Glow-worms put out their lamps 

 between eleven and twelve at night, and shone no more for the 

 rest of the night. 



Both sexes of the Glow-worm are represented on Plate VI., 

 the male at Fig. 1, and the female on his right at Fig. 2. The 

 dissimilarity between the sexes is very strongly marked, the 

 female being entirely wingless, while the male has large wings, 

 and elytra which cover the whole of the body. It is popularly 

 thought that the male does not possess the light-giving power ; 

 but this is a mistake, as every practical entomologist must 

 know. Still, though the male does possess a lamp, it is very 

 much smaller and feebler than that of the female, and, instead 

 of a mass of phosphorescence, throwing a radiance of some 

 inches in extent, it is nothing more than two tiny spots of light, 

 no larger than minnikin pins' heads. I once took a male 

 Glow-worm on the wing with his lamps lighted. 



As to the object of the light, it is a matter of very great 

 uncertainty. The obvious solution of the problem is to say 

 that the light is intended to guide the male to his mate ; and 

 if the naturalist be a classical scholar, he will be sure to make 

 an allusion to Hero and Leander — 



The chilling night-dews fall — away, retire ; 

 V For see, the Glow-worm lights her amorous fire ! 

 > Thus, ere night's veil had half obscured the sky, 



The impatient damsel hangs her lamp on high: 



True to the signal, by love's meteor led, 



Leander hastened to his Hero's bed. 



These lines, even though written by so acute a naturalist as 

 Gilbert White, are more poetical than true. I cannot of course 

 say that the light of the female may not act as a guide to her 

 mate, but I cannot see that this is the object of the light. 

 There are plenty of night-flying insects which manage to find 

 their mates in the dark without the use of any such aid, being 

 attracted to them by scent rather than sight: and, even if the 

 light emitted by the female Glow-worm be intended for such 

 a purpose, that of the male cannot be of the slightest use either 

 to him or to the mate whom he is seeking. 



Moreover, not only the perfect insects, but the pupae, the 

 larvse, and even the eggs are .^lightly luminous, so that in thesa 



