150 MIMICRY IN N. AMERICAN BUTTERFLIES 



defended species, whereby the loss of life incurred 

 during the education of young inexperienced 

 enemies was contributed between the similar 

 forms, instead of by each species independently 

 as would have been the case if they had been 

 dissimilar, and possessed patterns requiring each 

 a separate education. Such resemblance will be 

 spoken of as Miillerian Mimicry, the examples as 

 Mtillerian mimics, the interpretation as the Mill- 

 lerian Hypothesis. 



SPECIAL ADVANTAGES OF THE NORTH 



AMERICAN BUTTERFLY FAUNA FOR 



THE STUDY OF MIMICRY 



The butterfly fauna of North America affords 

 probably the best field in which to begin the 

 study of Mimicry, a subject which has been 

 shown to possess the most profound significance 

 in relation to the deepest problems by which the 

 naturalist is confronted. The examples are sharp 

 and striking, but not too numerous, and the 

 inquiry can be approached without the confusion 

 and excessive strain on the memory which must 

 inevitably at first beset the student of Mimicry in 

 the tropics. But outside the tropics it is also the 

 best field for this study, as will be sho.wn below. 



The western section of the Palaearctic Region is 

 sharply cut off by the Sahara from the Ethiopian, 

 and its few examples of Mimicry are not such 

 as would be likely to awaken the interest and 

 enthusiasm of the beginner. The eastern Palae- 



