THE BEETLE. 3S7 



which she sends forth to allure the male to her company. Most 

 travellers who have gone through sandy countries, must well re- 

 member the little shining sparks with which the ditches are 

 studded on each side of the road. If incited by curiosity to ap- 

 proach more nearly, he will find this light sent forth by the 

 glow-worm ; if he should keep the little animal for some time, 

 its light continues to grow paler, and at last appears totally ex- 

 tinct. The manner in which this light is produced has hitherto 

 continued inexplicable ; it is probable the little animal is sup- 

 plied with some electrical powers, so that by rubbing the joints 

 of its body against each other, it thus supplies a stream of light, 

 which if it allures the male, as we are told, serves for very use- 

 ful purposes.* 



rasionally to the surface of the water, in order to breathe. They swim with 

 pn'Ht celerity ; and in flying make a humming or droning noise like beetles. 

 The larvaj have powerful jaws, and six long legs. At the posterior part of 

 their body, which tapers towards the extremity, there are two small slen- 

 der processes, situated somewhat obliquely, aud moveable at the base. It is 

 hy means of these that the larva suspends itself at the surface of the water, 

 for the purpose of respiring the air of the atmosphere, which it does 

 through two small cylindrical tubes, situated at the extremity of the 

 tail. 



* It is a question hy no means decided, whether the light of the female 

 glow-worm is intended for the purpose popularly and poetically believed— 

 viz. as the lamp of love to attract and direct the vagrant msile. Bai-on 

 de Geer says that " this insect shines in its infant state, in that of larva, and 

 even after it has taken the form of a nymph. Now, as in the first of these 

 states it cannot propagate, and still less in the second, with what design is 

 tlie light displayed ? It must serve some purpose yet unknown. The an. 

 thors who have spoken of the male glow-worms say positively that they 

 shine in the dark ;is well as females." We have, says Mr Kennie, in two 

 instances observed this Iinninosity of the male, which however is much 

 more feeble than that of the female. Ray first discovered this fact in the 

 common glow-worm, and (ieolTroy and Muller give their testimony to its 

 accuracy; while lUiger records it as occurring still more remarkably in 

 two foreign species [Lumjitfris splendi/lula, and L. hemiptera). Kirby and 

 Spence make an attempt to rebut the inferences drawn from these facts, by 

 remarking that the circumstance of the male having the same luminou.s 

 property, no more proves that the superior brilliancy of the female is not 

 intended for conducting liim to her, than the existence of nipples, and 

 sometimes of milk in man, proves that the breast of woman 's not meant for 

 the support of her offspring. But we do not see how the light in the male 

 g!ow-worm can be thus compared with such decidedly sexual organs, _ 

 though in the larva it may certainly be explained upon the principle of 

 gradual development. Mr Main thinks that the design of the light in the 

 female is proved by the propensity of the males to fly towards light, and 

 itates that they have been seen iu such numbers, as sometimes to cover a 



