186 WAYS OF BUTTERFLIES 



as different as the flights of birds, and just as an 

 ornithologist may distinguish many birds by their 

 mode of flight when their form and colors are in- 

 distinguishable, so the observant entomologist may 

 often determine a butterfly from a considerable 

 distance. In the case of the entomologist, how- 

 ever, the decision is more difficult, since there are 

 such rapid replacements of one species by another . 

 throughout the summer that direct comparison of I 

 the flight of similar species is often impossible. 1 



