202 SMELL IN INSECTS. 



Insects, such as Dung-flies and Carrion Beetles, whose corres- 

 ponding office is to assist in ridding the earth of offensive 

 objects. That the sense of smell alone directs the Blow-fly in 

 the deposition of her eggs, has been fully proved by the fact 

 of her having, through misguided instinct been found to lay 

 them on silk wherewith tainted meat has been covered, or 

 upon the ill-odoured Stapelias, a tribe of .hot-house plants, 

 which in scent greatly resemble it. 



The Butterfly and Bee, with other winged collectors whose 

 more agreeable business lies among the odours, are equally 

 quick scented in their detection at distances almost incredible. 

 From a prodigious height, not less, it has been estimated, 

 than sixteen or twenty feet, the former lights down upon its 

 favourite flower ; while the latter wings its way for miles in the 

 exact direction of flowery fields and thymy downs, from which 

 scented breezes bring them invitation. Even when at hand, 

 it is the odour of flowers rather than their appearance by which 

 both Bees and Butterflies would seem to be enticed ; for it 

 was found by M. Huber, that four Bees and a Butterfly were 

 speedily assembled round some honey which he had placed, 

 for experiment, in a window, concealed by shutters only suffi- 

 ciently open to admit their passage. Availing themselves of 

 this liking for sweets and perception of their distant and 

 invisible presence, moth collectors are in the habit of anointing 

 the trunks of trees with honey or thick syrup, by which 

 means they attract and capture not a few varieties. 



