I 



Rare Collection of Insects, 37 



That these woods and their immediate surround- 

 ings impressed our young hero deeply, we can readily 

 see, as he frequently refers to the beauties and wealth 

 of the tropical foliage, and in one instance he com- 

 pares the effect to the " gayest scenery of the opera- 

 house or the great theatres." 



While in Brazil, Darwin formed the finest collec- 

 tion of insects ever made in this country, and 

 remembering his youthful fondness for beetle col- 

 lecting, his pleasure and enthusiasm can be appreci- 

 ated. In his notes on this work, we see evidences of 

 the theories that he formulated in later life. He was 

 impressed with the fact that the large butterflies 

 seemed highly coloured to conform with the gorgeous 

 foliage and flowers of their home. 



The beautiful Papilio ferotiia attracted his especial 

 attention, and he made a careful study of its pecul- 

 iarities, which might well be an example to young 

 naturalists. He noticed that it invariably alighted 

 with its head downward, with wings extended in a 

 horizontal plane, instead of being folded vertically. 

 When it moved, instead of edging off it ran, using its 

 legs nimbly for the purpose, surprising the young 

 naturalist with its agility. 



While watching this interesting creature, Darwin 

 discovered that it made a noise, and thus was the 

 first to listen, if not to the voice of the butterfly, to a 

 sound that is used for a similar purpose. He no- 

 ticed the noise when two butterflies were chasing 

 each other, a slight resonant clicking coming to his 

 ear, distinctly audible twenty yards away. He 

 describes it as resembling a " toothed wheel passing 



