292 THE COLOURS OF ANIMALS 



must signify her intention in some way unknown to 

 us, and that it is a point of honour with the males to 

 abide by her decision. 



I have watched the process exactly as I have de- 

 scribed it in a common northern Noctua, the Antler 

 Moth {Charceas graminis), and I have seen the same 

 thing among beetles. The fact is well known to ento- 

 mologists, and, as far as the evidence goes, it supports 

 Darwin's theory. 



The females of certain Butterflies more beautiful than 

 the males 



Another class of facts quoted by Darwin is barely 

 alluded to by Wallace ; but I think that it will be of 

 the utmost importance in deciding this question when 

 further and more detailed observations are made. 



The females of many butterflies are more beautiful 

 than the males, and then ' the plainer males closely 

 resemble each other, showing that here the females 

 have been modified ; whereas in those cases where the 

 males are the more ornate, it is those which have 

 been modified, the females remaining closely alike.' ^ 

 Many examples are found among our British butter- 

 flies, e.g. the Meadow Brown, the Clouded Yellow, 

 and the Whites. The females of such species support 

 the males during the marriage flight, while the oppo- 

 site is known to occur in many other butterflies. It 



» Darwin loc. cit. 1874, p. 318. 



