INSECTS. 355 



under surface resembles the flower-head of the wild parsley, 

 on which the butterfly often rests at night.* The same 

 reason which compels us to believe that the lower surfaces 

 have here been colored for the sake of protection, leads us 

 to deny that the wings have been tipped with bright orange 

 for the same purpose, especiall}' when this character is con- 

 fined to the males. 



Most moths rest motionless during the whole or greater 

 part of the day with their wings depressed; and the whole 

 upper surface is often shaded and colored in an admirable 

 manner, as Mr. Wallace has remarked, for escaping detec- 

 tion. The front- wings of the BombycidaB and Noctuid8e,f 

 when at rest, generally overlap and conceal the hind wings; 

 so that the latter might be brightly colored without much 

 risk; and they are in fact often thus colored. During 

 flight, moths would often be able to escape from their ene- 

 mies; nevertheless, as the hind wings are then fully exposed 

 to view, their bright colors must generally have been 

 acquired at some little risk. But the following fact shows 

 how cautious w^e ought to be in drawing conclusions on this 

 head. The common yellow under wings (Triphaena) often 

 fly about during the day or early evening, and are then 

 conspicuous from the color of their hind wings. It would 

 naturally be thought that this would be a source of danger; 

 but Mr. J. Jenner AVeir believes that it actually serves 

 them as a means of escape, for birds strike at these brightly 

 colored and fragile surfaces, instead of at the body. For 

 instance, Mr. Weir turned into his aviary a vigorous speci- 

 men of Triphcena pronuba, which was instantly pursued by 

 a robin : but the bird^s attention being caught by the col- 

 ored wings, the moth was not captured until after about 

 fifty attempts, and small portions of the wings were repeat- 

 edly broken off. He tried the same experiment in the 

 open air, with a swallow and T. fimbria ; but the large 

 size of this moth probably interfered with its capture. J; 

 We are thus reminded of a statement made by Mr. Wal- 



* See the interesting observations by Mr. T. W. Wood, " The 

 Student," Sept., 1868, p. 81. 



f Mr. Wallace in " Hardwicke's Science Gossip," Sept., 1867, p. 193. 



X See also on this subject, Mr. Weir's paper in " Transjict. Ejit, 

 Soc.,"1869, p. 23, ^ 



