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THE AMERICAN NATURALIST [Vol. L 



a Pierid or Danaid but containing in exchange "a Papilio, an 

 Acrcea, and two species of the Satyr-id genus Pedalodes." 



Assuming that one of these patterns must have been the most 

 primitive, he asks why a distasteful genus should change from 

 one efficient warning pattern to another quite distinct one. 

 Though the premise is not necessarily true nor even probable, 

 yet if the ancestral pattern were a generalized type of any 

 "warning" character whatever, the question would still be per- 

 tinent. 



The author suggests that a newly acquired color scheme, like 

 one of these, may be "associated with a certain physiological 

 constitution which places butterflies possessing it at an advan- 

 tage as compared with the rest," just as the melanic variety of 

 peppered moth that is ousting the typical form in Britain and 

 on the Continent may have associated with its deep pigmenta- 

 tion a greater hardiness. This, however, goes but a short way 

 toward the explanation of the extraordinary local associations of 

 unlike South American butterflies showing similar coloration. 

 This is a live question that challenges the attention of any stu- 

 dent of evolution who has opportunity to undertake experimen- 

 tal work in the tropics of South America. 



So if we must sooner or later consign Mimicry to its last rest- 

 ing place, with its less infirm but already moribund parent, 

 Warning Coloration, let us do so filled with gratitude for the 

 pioneer work accomplished by its champions in opening up 

 promising fields of investigation, where we or our descendants 

 may hope to discover new factors in evolution or to gain a deeper 

 insight into those now only dimly understood. Thanks are 

 meanwhile due to the author of this attractive volume for his 

 keen diagnosis of the present condition of the mimicry theory 

 and for his admirable description of the phenomena which it has 

 attempted to explain. 



John H. Gerould 



