208 THE COLOURATION OF INSECTS 



entice the enemy to seize an insect at some particular 

 part which is especially brittle, and, being seized, breaks 

 away, so that the insect escapes unharmed save for the 

 wholly immaterial loss of some part of the wing. Such 

 special directive marks often take the form of conspicuous 

 eye-like spots at the angle of the hind wing or along its 

 margin, or of tails, and every collector must have noticed 

 how often in Papilio, Charaxes, Satyrinae, Lycaenidae such 

 parts are missing, and a gap in the margin of the hind 

 wing shows where the enemy has secured nothing but a 

 mouthful of dry wing tissue. These gaps in the wing 

 are just in the position where the wings are least likely 

 to be damaged by contact with objects during flight. 

 Moreover, it is just these pieces of the wing which break 

 off when the butterfly is vigorously fluttering in the folds 

 of a net ; the tails of Papilionidae are notorious in this 

 respect. 



On one minute islet that I visited there were numbers 

 of black and white wagtails, and little Lycaenid butterflies 

 were plentiful. It was noticed that a large proportion 

 had a A-shaped piece missing from both hind wings 

 symmetrically as if a wagtail had seized the butterfly 

 by the hind wings when it was at rest, and the butterfly 

 had escaped owing to that portion of the wing breaking 

 away. After leaving the islands in 1915 I was fortunate 

 enough to see this actually happen, and also to see 

 numbers of Lycaenidae actually eaten by wagtails.^ The 

 question of directive markings has been here dealt with 

 because it seems possible that certain instances of very 

 simple, conspicuous patches of colour, which in the dead 

 specimen look like aposemes, are possibly directive mark- 

 ings, I refer especially to the orange, crimson, or purple 

 tips of the fore wings of the Pierine genus Teracolus. 

 These lovely butterflies are conspicuous on the wing, but 

 shy and wary. When one is fluttering in the net the 



1 Vide p. 238 



