64 THE CANADIAN NATURALIST. [Marcll 



The reason for the appearance of water beetles at such un- 

 seasonable hours may be accounted for thus : — In summer the 

 little ponds and pools are dried up, when it becomes necessary for 

 them to shift, and in their wanderings they are no doubt dazzled 

 and attracted by the light. 



The order Lepidoptera comprises the majority of our evening 

 visitors, such as moths. T'liere are three classes of these creatures, 

 divided into diurnal, twilight and nocturnal flyers. The eyes of 

 the nocturnal species are constructed something Hke the owls, that 

 is they are incapable of bearing the bright light of the^ sun. Any 

 one conversant with the habits of these creatures will have noticed 

 on confining a moth in a small box or in a partially darkened 

 room, how its eyes shine. This shews that a difference exists 

 between moths' eyes and those of other insects, — for instance, in 

 those of the dragon fly, which spends its day in the rays of the 

 sun, placed in a like position, no such effect is observed. This 

 bears out the suggestion that the visual organs of nocturnal 

 Lepidoptera reflect, and do not absorb, light. 



On the other hand, observe the appearance of some of the 

 Splingidae and other nocturnal moths. In the day-time we have 

 often observed them sticking to the trunk of a tree, or in the 

 crevice or corner of a fence. Failing to secure them instantly, 

 they would fly foolishly hither and thither, evidently annoyed by 

 the sunlight, darting among the brushwood and bushes till at last 

 they were captured, — none the better as cabinet specimens, on 

 account of their wings being rubbed or antennae broken. 



The purposes for which these creatures come out at night are 

 two-fold, — I speak here of the typical night flyers of the order 

 Lepidoptera. 



The first of these purposes is for feeding. The following cir- 

 cumstance will corroborate this view: — Having sugared some 

 trees on the mountain, I hung a lantern about two feet above 

 where the sugar was spread. The night was very suitable for 

 mothing, — dark and warm. We had not to wait long with our 

 nets before several moths made their appearance, and with ready 

 mouth, licked the sugar. Specimens of diptera also congregated, 

 attracted by the smell as well as the light. Few flew to the light, 

 but rested on or near the part rubbed with the sugar. The 

 second purpose is with a view to finding their mates in order to 

 perpetuate their species. It may be mentioned here that one of 

 the chief aims of an insect's life seems to be to accomplish this 



