116 ENTOMOLOGICAL NEWS [xxxii, '21 



Some Factors in the Classification of the 

 Microlepidoptera. 



By ANNETTE F. BRAUN, Cincinnati, Ohio. 



It is conceded that any truly scientific system of classification 

 should result in the grouping together of genetically related 

 forms. Classification by means of convenient characters which 

 arbitrarily assign species and genera to different groups with- 

 out regard to phytogeny, may result in a heterogeneous mix- 

 ture of species which, while possessing all the characters as- 

 signed to their respective group, and traceable to that group 

 in a "key," are of diverse ancestry. Such a system of grouping 

 adds nothing to our knowledge of relationship and phylogeny. 



The writing of the present paper was suggested by the all 

 too common tendency in systematic work to place undue em- 

 phasis upon some "ingle character or set of characters which 

 appears to solve some of the puzzling questions of relation- 

 ship. It is the purpose here to point out briefly and without 

 intention of covering the ground completely a few of the 

 guiding principles which should be followed in classification 

 and a few of the errors which it is necessary to avoid. The 

 examples are taken from the field of Microlepidoptera not 

 because other groups would not serve for illustration as well, 

 but because the writer is more familiar with this group and 

 better able to give examples. 



Classification rests on the affinities shown by weighing the 

 sum of all the characters of a form, the whole organism in all 

 its stages. It is to be expected that in related groups, certain 

 characters may reappear, because of a common inheritance. 

 In genetically unrelated groups the same character may develop 

 independently. This is one reason why no single character 

 can be relied upon exclusively. 



In classification, due regard must be paid to the relative 

 value of different characters. The adult indicates better than 

 any other sta^e the position of the species, because it repre- 

 sents the structure of the species after growth has ceased; 

 it is the most specialized and most complex (except in the 

 case of certain internal parasites). At any event it is the 

 last product in the evolution of that species, a structure which 

 is the final result and is influenced by all changes which have 

 taken place in evolution both in early and adult life. 



