IN COLORING AND STRUCTURE. 



199 



the most exquisite beauty and delicacy, scattered 

 among the more common sort, and invisible to 

 the naked eye. Even with the help of the micro- 

 scope they can often only be discovered by ruf- 

 fling the plumage and forcibly extracting them 

 from their concealment. And so far as we can see 

 they rarely give the wing any peculiar character by 

 which it may be distinguished from other wings. 



These peculiar scales, or an- 

 droconia as they may be termed, 

 in reference to their masculine 

 nature, were first noticed by Ber- 

 nard-Deschamps more than forty 

 years ago, but have never been 

 properly studied throughout the 

 butterflies. Deschamps called 

 them plumules from their feathery 

 tips ; but this term is utterly 

 inappropriate to most of them ; 

 and 



only some word expressing their 

 masculine character should be accepted, since this 

 is their single common peculiarity. 



These androconia are very capricious in their 

 occurrence ; a number of allied genera may pos- 

 sess them, while a single genus, as closely allied, 

 may be quite destitute. This is true throughout 

 the butterflies ; and yet there are large groups in 

 which they are altogether wanting, and others in 



FIG. 164. Scales of 



, -, . . . -. , Senmopsyche Diana ; 



their lOrin IS SO Varied that a, androconium ; b, 



ordinary scale ; X 285. 



