PIGMENTS OF MODELS AND MIMICS 263 



a closely similar constitution. These three pigments, 

 with black, which is apparently intimately associated with 

 the cuticle of the scales, with a pigment placed between 

 the two laminae of the wing and with superadded optical 

 effects due to structure, account for the whole of the 

 colouring of Pierine butterflies. No pigment of similar 

 constitution to the Pierine white, yellow, and red, was 

 found by Mr. Hopkins in any other butterfly — not even 

 in the allied Paptlioninae. The Pierine butterflies which 

 resemble the Ithomiinae or other butterflies were found 

 by Mr. Hopkins to achieve this end, not by gaining the 

 true pigments of their models, but by means of the cha- 

 racteristic Pierine pigments. The bands of warm red- 

 brown, the spots of white and yellow, which so closely 

 resemble the same tints in the Ithomiinae, are in reality 

 caused by pigments of an entirely different nature, — the 

 resemblance, even between the pigments themselves, is 

 wholly superficial. 



The argument that the resemblances we are discussing 

 are a common result of common forces is simply an 

 improbable assumption. It has been proved again and 

 again that the results are not common, the resemblance 

 merely deceptive. And now this has even been shown 

 for the colours themselves, in some of the best known 

 and most striking examples of Mimicry. 



The last example of similarity in appearance produced 

 through diversity of method is one which occurred to me 

 a few years ago when lecturing on Mimicry in the Hope 

 Department at Oxford. It was worked out in detail 

 during the summer of 1897, and the general results were 

 communicated to Section D of the British Association at 

 Toronto. 1 



Although the Lepidoptera are characterized as an Order 

 by the clothing of scales upon the wings, examples are 

 very frequent in which this covering has been in part, 

 or almost wholly, lost. By comparison with kindred 

 unmodified forms, as well as by microscopic examination 

 of the transparent areas themselves, it is possible to show 



1 August 23, 1897. A brief abstract is printed in the Report of the 

 Meeting, pp. 692-4. 



