206 THE COLOURS OF ANIMALS 



behind the body. The notches generally corresponded 

 on both hind wings, the insect having been seized at 

 the instant when the wings came together in flight, 

 or during one of its short pauses upon a flower. From 

 the position of the injury it is clear that the enemies 

 were aware of the situation of the body and attempted 

 to seize it, but that they had been frustrated by the 

 swift and wary butterfly with its bright yellow wings 

 extending behind the short body, and offering an 

 apparently convenient point for seizure. 1 



The bright yellow black-bordered under wings of 

 the moths of the genus Tryphcena (Yellow Underwings) 

 also possess this among their other meanings, as Mr. 

 Jenner Weir has pointed out : they are exposed during 

 flight, and their colours are far brighter than any other 

 part of the insect. It is also very common to find the 

 margin of these wings notched in captured specimens, 

 and this is often the case when all other parts are fresh 

 and perfect. The red and black under wings of the 

 genus Catocala (including the Bed and Crimson 

 Underwings) are perhaps useful in the same way. 



A still more interesting and obvious character of 

 this kind is to be found in markings which actually 

 suggest the presence of a vital part, such as an enemy 

 would be likely to seize. On one occasion I intro- 



1 Skertchly has found such mutilations not uncommon among 

 Bornean butterflies : he also notices the correspondence of the injury 

 on the two sides. The wings are not torn in this way by flying 

 through thick branches ; Skertchly states that even the most fragile 

 butterflies can pass unharmed through dense undergrowth. 



