MIMICEY BETWEEN MIMICS 183 



section to which they belong, should incidentally 

 approach one another. But the strong likeness 

 between the mimetic forms of troilus, astenus, and 

 ghucm seems to require something more than this, 

 and supports the conclusion that there is secondary 

 Mimicry between the mimics themselves. It is 

 not necessary to repeat here the details of these 

 secondary resemblances,' and as a matter of fact 

 the likeness itself is stronger than might be 

 inferred from a consideration of the details them- 

 selves. It is necessary to see it in order to 

 appreciate it. 



It is probable that troilus, mimetic in both 

 sexes, is the oldest mimic ; astenus, non-mimetic 

 on the upper surface of the male or with very 

 rough incipient Mimicry, the next to appear ; and 

 ghitcus, mimetic in only one form of the female, 

 the youngest. These conclusions as to relative 

 age are on the whole supported by the relative 

 strength of the detailed resemblances to pMlenor 

 in the three mimics. 



In attempting to trace the past history, here 

 again we have the great advantage of knowing the 

 more ancestral patterns from which the three 

 mimics were derived : — troilus from a palamedes- 

 like form ; astenus from the pattern of its male, 

 which again leads back to the typical pattern 

 of the Machaon Group; the turnus female of 

 glaucus from the male and non-mimetic female 

 of the same species. 



' See Trans. Ent. Soc. Lond. (1908), 467-71. 



