358 THE NATURAL HISTORY 



The second family is limited to several species of 

 those four-winged flies so well known to the scientific 

 angler, and, we are sorry to confess, so little known to 

 ourselves. Like the Dragon-flies, they frequent the 

 banks of our ponds and water-courses, in which they 

 have passed through all their stages of development. 



The May-flies are classed in the third family, the 

 Ephemera vulgata being the typical form, and a great 

 many of the species are associated with those of the 

 preceding group in the angler's catalogue of " killing 

 flies." The larvae and pupae of these insects are 

 aquatic, living on decaying vegetable matter, and 

 many of them residing in burrows in the mud, which* 

 they make themselves. The perfect insect, with its 

 reticulated wings and three caudal filaments, is too 

 common to need any particular description, it is chiefly 

 in its habits that it is remarkable. After having un- 

 dergone its change from the larva to the pupa, and 

 emerged from the pupa-skin as an apparently perfect 

 insect, it is not until it has divested itself of an addi- 

 tional garment, so fine that the fact of its existence 

 might scarcely be suspected, that it is competent to 

 take part in the social pastime these short-lived crea- 

 tures indulge in. This, and the business of reproduc- 

 tion, are their only concerns in the perfect state, which, 

 as a rule, does not extend beyond a few hours, during 

 which they take no food whatever. Indeed the dif- 

 ferent parts of the mouth are so rudimentary, that 

 they are utterly useless ; even the mouth itself is so 

 imperfectly developed that, according to Reaumur, it 

 is simply represented by an inconspicuous vesicle. 

 The fiat, therefore, has already gone forth, " edisti 

 satis, tempus adire domum\" accordingly the female 

 dies as soon as she has laid her eggs, and her com- 

 panion either falls a prey to fish or the voracious 

 dragon-fly, or quietly disappears in some other way 

 from the scene of his ephemeral dance. Those of our 

 readers to whom a sensational record of the occurrence 



