INTRODUCTION. 



ditions in other species before referred to. The beautiful purple of 

 Apatura iris and its allies is unpigmented, as may easily be imagined 

 from the fact that the colour is only obtainable when the rays of light 

 strike the scales at a certain angle. 



These remarks on the genetic relationship of the colours of our 

 British lepidoptera are not presented as a complete exposition of the 

 subject, but are rather the result of isolated suggestions which the 

 study of variation has now and again presented to me. 



