58 SOME CRITICISMS [ch. 



nattiralists who have grown up in a region where 

 the majority of the "whites" are more or less white. 

 For this reason the statement that D. praxinoe differs 

 from the biilk of its allies is hkely to meet with 

 general acceptance, especially as some of the species 

 of the genus itself (e.g., D. cretacea, PI. X, fig. 1) 

 are regular whites in appearance. But when we 

 come to look at the genus DismorpMa as a whole the 

 matter assumes another complexion. Seitz ^ recognises 

 75 species of which about a dozen are predominantly 

 white. The rest present a wonderful diversity of 

 colour and pattern. Black predominates on the fore 

 wings, and the insect is frequently marked with gay 

 patches of yeUow, bright brown, scarlet, or blue. 

 Forms which from their colour are clearly not mimics 

 present nevertheless the general pattern and shape 

 of other forms which bear a strong resemblance to 

 some Ithomiine. Sometimes a change of colour in 

 certain patches from blue or yeUow to bright brown 

 would make aU the difference between a non-imitative 

 and an imitative species. Moreover, the non-imitative 

 forms frequently have the peculiar narrow wing, so 

 unusual in a Pierine, which enhances the resemblance 

 of the mimicking species to the Ithomiine model, 

 and which to some extent occurs even in D. cretacea. 

 .Clearly we are not justified in saying that D. praxinoe 

 differs from the bulk of its alHes, for inside the genus 

 there are many non-imitative species which differ 



^ Macrolepidoptera of the World. Fauna Americana, pp. 98-104, 

 Plates 28-30. 



