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III. On the Relation of Mimetic Patterns to the Original 

 Form.^ By Frederick A. Dixey, M.A., M.D., 

 F.E.S., Fellow of Wadham College, Oxford. 



[Read Feb. 5th, 1896.] 

 Plates III, IV., & V. 



I. The Gradual Growth of a Mimetic Pattern. 



It is now many years ago that Fritz Miiller published 

 an answer to those opponents of the theory of mimicry 

 who made much of the difficulty of accounting for the 

 first advances towards the formation of a mimetic 

 pattern. t In the course of this communication he 

 pointed out (as indeed Darwin had done before him) 

 that mimicker and mimicked might, in many instances, 

 be reasonably supposed to have started, not from a 

 position of wide divergence from each other, but rather 

 with the possession of some feature or features, common 

 to them both, which should give material ready to hand 

 Tor the assimilative process to work upon. The chief 

 instance relied on by Fritz Miiller in support of his 

 contention was the well-known mimetic genus of 

 Pierine butterflies known as Leptalis or Disniorphia.X 

 The black and yellow Leptalis (Dismorphia) melia, 

 according to him, was to be regarded as representing 

 the primitive type of coloration of the genus ; and 

 although it did not itself mimic any other form, it never- 

 theless showed independently so much of the character- 

 istic Heliconine colours and arrangement of pattern, 

 that the complete Heliconine aspect presented by many 

 of its near relatives could be derived from it with com- 

 paratively slight modification. 



"■ A preliminary abstract of the present paper has appeared in 

 the British Association Reports for 1894. 



t " Einige Worte iiber Leptalis,'' Jenaisch. Zeitschr., vol. x., 

 1876, p. 1. 



J The old genus Dhmorphia has been divided by Messrs, 

 Godman & Salvin into Dismorphia, Pseudopieris, Enanliu, and 

 Acmepteron, Biol, Centr.-Amer., Rhopal. II., p. 174. Dr. Butler 

 further distinguishes Moschoneura, Cist. Entom., Pt. iii. 



TRANS. ENT. 60C. LOND. 1896. — PART 1. (ilARCH.) 5 



