ARTICLES 



SOME ASPECTS OF ANIMAL COLOURA- 

 TION FROM THE POINT OF VIEW OF 

 COLOUR VISION 



BY J. C. MOTTRAM, M.B. Lond., 



The Middlesex Hospital, London 



AND 



F. W. EDRIDGE GREEN, M.D., F.R.C.S., 

 Ophthalmic Surgeon, National Service Medical Boards, South London Area 



PART I 



As far as we are aware, animal colouration has not been con- 

 sidered from the point of view of colour vision : and as the 

 knowledge of colour vision has been greatly advanced (Edridge 

 Green, Science Progress, Jan. 191 5) during recent years it 

 would seem that such a consideration is now called for. No 

 attempt is here made to deal exhaustively with the subject, 

 but only to discuss a few of the more important facts, to 

 correct certain interpretations, and to give to others an im- 

 portance which has been overlooked. 



The dorsal surfaces of the wings of diurnal Lepidoptera is 

 the material first chosen for analysis because they present 

 great diversity of colouration, and unlike the ventral surfaces, 

 seldom directly imitate natural surroundings. The Indian 

 Lepidoptera (Moore's Lepidoptera Indicd) were selected on 

 account of their careful description and illustration in colour 

 (the Hesperidse were omitted). It was found that the colours 

 can, with hardly any difficulty, be classified into red, orange, 

 yellow, green, blue, violet, black, brown, and white. Other 

 colours, such as purple and grey, so rarely occur that a very 

 much larger series would require to be investigated, in order 

 to obtain information of value about them. Certain difficulties 

 arise when such colours as orange-red, yellow-orange, and yellow- 

 brown have to be classified, but in the majority of cases, descrip- 

 tion in the text decides the case : a second opinion was also often 



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