32 BUTTERFLIES 



and is a striking example of both dazzling and mimicking 

 coloration. 



Many of our own butterflies, notably the Angle-wings, 

 are excellent examples of a similar combination. In flight 

 they reveal conspicuous colors which are instantly hidden 

 upon alighting and then one only sees the bark-like or dead 

 leaf -like under surface as may be seen in the plate opposite 

 pages 160-161. The iridescence upon the upper wing surface 

 of many butterflies, whose under wing surface is colored in 

 concealing tones, is doubtless also of great use to the insect 

 in a similar way. There is a splendid opportunity here for 

 some observer to study this phase of butterfly activity and 

 to get photographs of the insects amid their natural sur- 

 roundings. 



In their book upon " Concealing Coloration" the Messrs. 

 Thayer have called attention to many interesting phases 

 of dazzling coloration. They show that bright marks like 

 the eye-spots or ocelli, which form so prominent a feature 

 on the wing surfaces of many butterflies, really helped to 

 conceal the insect amid its natural surroundings, by draw- 

 ing the eye away from the outlines of wings and body so 

 that the latter tend to disappear. Their discussion of this 

 subject opens up another vast field for outdoor observa- 

 tions of absorbing interest, in which there is great need for 

 many active workers. 



Selective Color Sense 



One who collects the Underwing moths soon discovers 

 that the light colored species which resemble the bark of 

 birch trees are likely to be found upon the trunks of those 

 trees, and that the dark colored kinds which resemble the 



