Chap. XI. BUTTERFLIES AND MOTHS. 395 



(Triphaena) often fly about during the day or early 

 evening, and are then conspicuous from the colour of 

 their hind-wings. It would naturally be thought that 

 this would be a source of danger ; but Mr. J. Jenner 

 Weir believes that it actually serves them as a means 

 of escape, for birds strike at these brightly coloured and 

 fragile surfaces, instead of at the body. For instance, 

 Mr. Weir turned into his aviary a vigorous specimen of 

 Triphaena pronuba, which was instantly pursued by 

 a robin ; but the bird's attention being caught by the 

 coloured wings, the moth was not captured until after 

 about fifty attempts, and small portions of the wings 

 were repeatedly broken off. He tried the same experi- 

 ment, in the open air, with a T. fimbria and swallow; 

 but the large size of this moth probably interfered 

 with its capture. 8 We are thus reminded of a state- 

 ment made by Mr. Wallace, 9 namely, that in the Bra- 

 zilian forests and Malayan islands, many common and 

 highly-decorated butterflies are weak flyers, though fur- 

 nished with a broad expanse of wings ; and they " are 

 "often captured with pierced and broken wings, as if 

 '• they had been seized by birds, from which they had 

 " escaped : if the wings had been much smaller in pro- 

 " portion to the body, it seems probable that the insect 

 " would more frequently have been struck or pierced in 

 "a vital part, and thus the increased expanse of the 

 " wings may have been indirectly beneficial." 



Display. — The bright colours of butterflies and of 

 some moths are specially arranged^for display, whether 

 or not they serve in addition as a protection. Bright 



8 See also, on this subject, Mr. Weir's paper in ' Transact. Ent. Soc' 

 1869, p. 23. A/ O "os Hl 



9 ' Westminster Review,' July, 1867, p. 16. 



lL jiLIBR f 



