28o THE WONDERS OF INSTINCT 



of chloroforming his prey by means of a few tweaks re- 

 sembling kisses, he would be unknown to the vulgar 

 herd; but he also knows how to light himself like a 

 beacon; he shines, which is an excellent manner of 

 achieving fame. Let us consider more particularly the 

 female, who, while retaining her larval shape, becomes 

 marriageable and glows at her best during the hottest 

 part of summer. The lighting-apparatus occupies the 

 last three segments of the abdomen. On each of the 

 first two it takes the form, on the ventral surface, of a 

 wide belt covering almost the whole of the arch ; on the 

 third the luminous part is much less and consists simply 

 of two small crescent-shaped markings, or rather two 

 spots which shine through to the back and are visible 

 both above and below the animal. Belts and spots emit 

 a glorious white light, delicately tinged with blue. The 

 general lighting of the Glow-worm thus comprises two 

 groups: first, the wide belts of the two segments preced- 

 ing the last; secondly, the two spots of the final segments. 

 The two belts, the exclusive attribute of the marriage- 

 able female, are the parts richest in light: to glorify her 

 wedding, the future mother dons her brightest gauds; 

 she lights her two resplendent scarves. But, before that, 

 from the time of the hatching, she had only the modest 

 rush-light of the stern. This efflorescence of light is the 

 equivalent of the final metamorphosis, which is usually 

 represented by the gift of wings and flight. Its brilliance 

 heralds the pairing-time. Wings and flight there will be 

 none : the female retains her humble larval form, but she 

 kindles her blazing beacon. 



