COLOR AND COLORATION 



167 



coloration, but also in size and form; marcellns appears first, in spring; 

 tela mo nides appears a little later (though before marcellus has disappeared) ; 

 and dja.v is the summer form; as the season advances the varieties be- 

 come successively larger, with longer tails to the hind wings. 



Now Edwards submitted chrysalides of the summer form aja.v to 

 cold and thereby obtained, in 

 the same summer, butterflies 

 with the form of ajax but the 

 markings of the spring form 

 telamonides. Some of the 

 chrysalides, however, lasted 

 over until the next spring and 

 then gave telamonides. 



In Phyciodcs tliaros (Fig. 

 234) the spring and summer 

 broods, termed respectively 

 marcia and morpheus, were 

 at first regarded as distinct 

 species. In marcia the hind 

 wings are heavily and diffusely 

 marked beneath with strongly 

 contrasting colors, while in 



morpheus they are plain and but faintly marked. Edwards placed upon 

 ice eighteen chrysalides that normally would have produced morpheus; 

 but instead of this, the fifteen imagines that emerged were all of the 

 spring form marcia and were smaller than usual. Pupa? derived from eggs 



FIG. 233. Iphidides ajax, form telamonides, on 

 flower or button bush. Reduced. 



\ * ' 



A 



B 



FIG. 234. Pliyciinli's lliaros; .1, spring form, marcia; B, summer form, morpheus; under 



surfaces. Natural size. 



of marcia gave, after artificial cooling, not morpheus, but marcia again. 

 The evident conclusion is that the distinctive coloration of the spring 

 variety is brought about by low temperature. In Labrador, only one 



