BEETLES THAT "BLUFF" 233 



it would seem more likely to be a relatively recent inno- 

 vation. The nearly-related Alder-flies {Sialida), so well 

 known to anglers, seem like to meet with a similar fate, 

 for the female lives but for a few days only and the male 

 has an even briefer existence as a winged insect. The 

 family to which the Alder-flies belong contains a few 

 species which attain gigantic proportions, as, for example, 

 in the case of the North American members of the genus 

 Corydalis, which are giants. The males thereof are 

 remarkable for the fact that they are armed with enormous 

 jaws, which may be likened to a pair of callipers whose 

 limbs have been crossed. These weapons serve as claspers, 

 enabling the males to seize and hold the females during 

 the act of mating. But even here the same brief span 

 of life has to suffice them, for death follows swiftly on 

 the fulfilment of the nuptial rites. 



The Perlidae, or Stone-flies, which, like the Sialidae, 

 are aquatic Neuroptera, the larval stages being passed 

 in streams, present very puzzling features in regard to 

 the adult males which, so far, have baffled all attempts 

 at solution ; yet they seem to have a very important 

 bearing on the all-important work of reproduction. 

 They are among the earliest insects to appear in spring, 

 and possess an extraordinary power of resisting cold. 

 One species, Capina vernalisy common in the Albany 

 River, in Canada, frequently comes up through cracks 

 in the ice and casts its skin there ! Another, Nemoura 

 glacialis, which appears at about the same time, actually 

 performs the nuptial rites in crevices in the dissolving 

 ice ! Happily reason is denied them, or they would find 

 life a mockery indeed ; for having attained their final 

 development, when the joyous and exhilarating exercise of 

 flight should be theirs, they are compelled forthwith to 



