204 MIMICRY IN N. AMERICAN BUTTERFLIES 



2. North America is the most suitable area in 

 the world in which to begin the study of Mimicry. 



3. The great American Danaine butterflies, 

 formerly included in the genera Anosia and 

 Tasitia, are a foreign element in the New World 

 fauna. They bear the closest affinity to a large 

 group of indigenous Old World Danainae, and 

 should be fused with the nearest of these (Limnas 

 and Salatura) into a single genus, Danaida. 



4. The Old World origin of Danaida is also 

 proved by the extent and variety of its mimetic 

 relationships ; while the path of its invasion of 

 the New World and of South by way of North 

 America, may be traced by foot-prints, as it were, 

 of mimetic effect. 



5. That Danaida plexippus is the older invader 

 is equally shown by the depth of the impression 

 it has made and the amount of change it has itself 

 undergone in the New World. 



6. Danaida berenice and its form strigosa show 

 comparatively slight changes in the New World, 

 and, as regards mimetic influence, have but deep- 

 ened the foot-prints left by plexippus. 



7. Limenitis arihemis, the indigenous ancestor 

 of the mimic of plexippus, persists with little or 

 no change ; and it is possible to show how far the 

 very different markings of the mimetic daughter- 

 species, L. archippus, have been carved out of 

 those of the parent. 



8. The recent date of this great superficial 

 transformation is proved by the close resemblances 



