APPENDIX. 



The colour patterns of Butterflies appear to be 

 derived through various modifications from two very 

 simple type patterns, wrought with one or both of two 

 kinds of scales. 



A. First Type-pattern. Wings having simply 



a pale ground, or pale with lines composed 

 of dark scales along the veins. Example: 

 Aporia cratcBgi. British. 



B. Second Type-pattern. Wings having a pale 



ground with an orange or red blush occupying 

 the central area. Gonepteryx Cleopatra. 

 European. 

 There are also two kinds of scales: 



C. Scales coloured by Pigment. White, Yellow, 



Brown, Black, Red, and some kinds of blue. 



D. Iridescent Scales, deriving their colour chiefly 



from the striation of their surface. Gold, Sil- 

 ver, Blue, Green, Amethyst, Crimson, &c. 



Modifications : 



A'. Dark lines attenuated, visible only at the tip, 

 and there expanded. Pleris Brassicce. British. 



A". Dark lines expanded, forming patches and 

 scallops. Arge Galathea. British. 



A". Dark lines expanded, forming a blackish area, 

 and leaving the pale ground visible only in 



