114 THE CANADIAN KNTOMOLOGlST. 



THE ORIGIN OF ORNAMENTATION IN THE LEPIDOPTERA. 



BY A. R. GROTE, A. M., BREMEN, GERMANY. 



Elsewhere I have ventured to call attention to the interesting chapter 

 in Mr. Scudder's book on Butterflies, in which the theory as to the primi- 

 tive pattern of ornamentation is given. By this we are told that the com- 

 plex patterns, the seemingly chiselled lines and the eye-like spots, arose 

 from simple transverse shade bands running parallel to the outer margins 

 of the wings themselves. Such bands we yet find on the wings of many 

 Owlet Moths. In the Moths we might expect to find, still existing, a 

 nearer approach to the primitive style of marking than in the higher 

 Butterflies. Mr. Scudder's theory of the primitive pattern is quite inde- 

 pendent of the theory as to the origin of the primitive transverse shade 

 lines themselves. Referring to what I have said in my " Essay on the 

 Noctuidse " and in other places, about the pattern of one wing being re- 

 produced in some species exactly, and in some whole families in the style 

 of a rougher copy, upon the under-lying wing, I have employed the word 

 " photographed " to express the effect produced. The primitive band 

 may then be conceived to have been produced by an outside process, the 

 effect of light and shade upon the surface of the wing itself. Its produc- 

 tion may have been aided by the movement of the wings (expanding and 

 shutting). The edges of the wings in many ways may be conceived to be 

 first affected. That the primitive Lepidopteron was plain and sombre, we 

 have reason to suppose, judging from what is known of now extinct types 

 from which the whole Order may have been evolved. Under the murky 

 skies of the Carboniferous the colors of the insects remained dull. Upon 

 this plain wing, the first shade or marking may have arisen by a process 

 comparable with photography, the action being produced by the same 

 chemically acting ray of light. The atmospheric conditions then existing 

 are factors in the problem. The shadow originally cast on the wing left a 

 trace in process of time, a deeper tinting which became a permanent 

 shade line or band. The evolution of this primitive shade band is the 

 subject of Mr. Scudder's theory. The manner in which it may have arisen 

 from a shadow has been long the subject of my own thoughts. I am 

 aware that there is a learned opinion that the colors and patterns of insects 

 are developed from the insects' insides, by a process the links in which I 

 am unable to follow, and which it has not pleased the authors of this 



