44 NEW-WORLD MIMICS [ch. 



or may not bear a patch which is generally whitish 

 in the female, though often of a brilliant blue or green 

 in the male. This simple colour scheme with varia- 

 tions runs throughout about three-quarters (some 

 40 species) of the Poison-eaters. The same general 

 colour scheme is also found in about two dozen species 

 of the unprotected Swallow-tails. As the total number 

 of the unprotected species is placed by Seitz at less 

 than 100 this means that fully one-quarter of them 

 fall into the general colour scheme adopted by the 

 majority of the Poison-eaters. In many cases the 

 resemblance between mimic and model is so close as 

 to have deceived the most expert entomologists before 

 the structural differences between the groups had 

 been appreciated (cf. Appendix II). The matter is 

 further complicated by the fact that polymorphism, is 

 not uncommon, especially among the females of the 

 mimetic forms. Papilio lysithous for instance has no 

 less than six distinct forms of female, which differ 

 chiefly in the extent and arrangement of the white 

 markings on the wings, one form lacking them entirely. 

 Several of these forms may occur together in a given 

 locality, and may resemble as many distinct species 

 of Poison-eaters. Thus the three forms lysithous, with 

 white on both wings, rurik, with white on the fore 

 wing only, and pomponius without any white, all fly 

 together in Rio Grande do Sul and respectively mimic 

 the three distinct Pharmacophagus species nephalion, 

 chamissonia, and perrhebus (PL XIII). It is worthy 

 of note that mimics are provided by both unprotected 



