8 THE CANADIAN ENTOMOLOGIST. 



position, and so do some of the western forms. All these, as is also the 

 case in the Cicindelidae cited, are offshoots from the same stock which 

 have varied gradually as they spread over a larger territory, and became 

 gradually local and fi.xed, but yet show their relationship by their identity 

 of structure. 



Satyriis shows no structural differences except a slight one in wing 

 form, separating what I term group alope and group siivestris. All the 

 species of each group show their intimate relationship. 



To Coleopterists I need hardly speak. Dr. Horn takes every oppor- 

 tunity of saying that color and maculation do not alone suffice for specific 

 separation ; only structural characters should be recognized. 



Lepidopterists have not yet come to that conclusion. Not only is 

 structure not regarded in the question of a new species, but characters are 

 used — color differences — which are known to vary in allied species. Take 

 the species of Argynnis, for instance : What are they based upon ? Slight 

 variations in maculation, which an examination of a large series of cybeU^ 

 aphrodite or atlantis, show to be inconstant. 



Yet structural characters are by no means wanting in the Lepidoptera. 

 Of over 200 species of Agrotis examined by me, two-thirds show obvious 

 differences in structure, and the others differ in other obvious characters 

 exclusive of color. 



Of the species of Ma7ncstra thus far examined by me, no two agree 

 entirely in structure ; and indeed throughout the Noctuids good species 

 are very generally separated by distinctive structural peculiarities. That 

 the Diurnals and Bombycidse show similar variations is almost certain, and 

 as soon as students in these groups will cease to rely upon minute differ- 

 ences in color and maculation, but will accept the facts that western species 

 vary quite as ranch and perhaps more than eastern species, then will it be 

 possible so to describe a species that it can be recognized. 



The tendency of all species is to vary in color and maculation, and 

 the variations also tend to become locally permanent ; still these local 

 forms cannot yet be regarded as anything but races— certainly not species, 

 and it is not only confusing, but discouraging, to see a series of Colias, 

 Argynnis or Satyrus all named as species, differing by such trivial char- 

 acters that one dares not remove a label or change the position of an 

 insect for fear that the species could not be again recognized. 



It is thoroughly illogical at all events for a student to accept the theory 

 of evolution, which necessarily precludes the idea of fixedness in species, 



