68 



SCIENCE PROGRESS 



The Consideration of Brown 



Referring to diagram No. i, it is seen that the colours 

 are for the most part laid down in small areas ; only in the case 

 of blue, yellow, and brown do large and moderate areas com- 

 monly occur. This is better seen in diagram No. 2, where all 

 the colours have been reduced to 100. Large brown occurs 

 in 30 per cent. Details of this distribution are more fully 

 given in the diagrams which deal with five groups given separ- 

 ately — the Euploeinae (diagram No. 3), the Satyrinae (diagram 



r 70 



Euploeio* (70) 



50 



minim 



30 



G 



R 



O 



W 



minim 



Bl 



10 



Br 



SD 



Diagram No. 3. 



SD. represents species in which there is sexual dimorphism in colour. The numbers after the group 

 names give the number of species dealt with. 



No. 4), the Nymphalinae (diagram No. 5), the Papilionidae (diagram 

 No. 6), and the Pierinae, Eroninae, and Coliinae (diagram No. 7). 

 It can be seen that large brown is chiefly to be found in the 

 Satyrinae and Euploeinae. The arrangement of these large 

 areas is entirely different in the two groups : in the Satyrinae 

 it occupies the centre of the insects' wings and is bounded by 

 marginal pattern, whereas in the Euploeinae the whole wing is 

 coloured an even dark brown, or if a pattern is present it is 

 situated at some distance from the margin. In previous papers 

 (Proc. Zoo. Soc. 191 5, p. 679; 1916, p. 283) it has been shown 





