82 THE CASE OF PAPILIO POLYTES [ch. 



to the insect when settled, even at a distance of several 

 yards, and this although one may be perfectly familiar 

 with its harmless nature. The mimics on the other 

 hand with their sombre-coloured bodies never look 

 otherwise than the inoffensive creatures that they are. 

 The "dangerous" look due to the brilliant scarlet of 

 the body and head of hector and aristolochiae is re- 

 inforced by the quality of the red on the markings of 

 the wings. In both models it is a strong clamorous 

 red suggestive of a powerful aniline dye, whereas such 

 red as occurs in the mimics is a softer and totally 

 distinct colour. The difference in quality is even more 

 marked on the under than on the upper surface (PL V, 

 figs. 3 a — 6 a), and the net result is that when settled, 

 with wings either expanded or closed, there is no possi- 

 bility of an ordinarily observant man mistaking mimic 

 for model in either case, even at a distance of several 

 yards. 



It may, however, be argued that it is not when at 

 rest but during flight that the mimetic resemblance 

 protects the mimic from attack. Actually this can 

 hardly be true, for the mode of flight constitutes one 

 of the most striking differences between model and 

 mimic. P. hector and P. aristolochiae fly much in the 

 same way. They give one the impression of flying 

 mainly with their fore wings, which vibrate rapidly, 

 so that the course of the insect, though not swift, is 

 on the whole sustained and even. The flight of all the 

 different forms of polytes is similar and quite distinct 

 from that of the models. It is a strong but rather 



