Chapter XVIL 



Rest of Insects. 



Mr Brightwell is reported to have once ob- 

 served an individual living specimen of Haltica con- 

 cinna, which appeared to remain motionless on the 

 same spot of a wall for three successive days;* but 

 though this is given as something unusual, we have 

 made similar observations in the case of numerous in- 

 sects of all orders and families. The continual sta- 

 tionary appearance, however, is, in most of such cases, 

 quite fallacious. To use a familiar illustration, we 

 might as well think the snail stationary which we see 

 every day, perhaps for weeks together, coiled up in 

 the same niche of the garden-wall, as if it were glued 

 to the spot, and had never moved from it a hair's- 

 breadth, — ■ were it not that the depredations committed 

 upon a contiguous lettuce, prove that it does not 

 always sleep, though its excursions from its chosen 

 niche, as they take place only at night, are seldom, if 

 ever, observed. Like a very large portion of the 

 whole insect world, snails always sleep throughout 

 the day, unless roused by an accidental shower of rain, 

 which tempts them to banquet on the refreshed 

 herbage. Upon butterflies, and some other day in- 

 sects, again, the occurrence of rain or cloudy weather 

 usually operates like a continuance or a renewal of 

 night; and this seems to happen even in-doors, where 

 the air is warm and comparatively dry. We had a 

 female of the brimstone butterfly ( Gonepteryx 

 Rhamni) in our study, which we were desirous of 



* Kirby and Sponce, Intr., vol. iv, p. 193. 



