158 PROCEEDINGS OF THE AMERICAN ACADEMY 



ual ; in one group (Hiesperides) there are hair-like androconia, and 

 others wliich are exceedingly hirge and spindle-shaped. In the Astyei, 

 besides hair-like and gigantic androconia, there are usually some which 

 are spoon-shaped, with long handles. 



As a general rule, these androconia are present in the patches to 

 which we have alluded as forming oue phase of the antigenic charac- 

 ters of the male ; but often, as in the Adolescentes and Voracia, they 

 are scattered indiscriminately or in rows over the upper surface of the 

 wings ; and there are many patches, like those at the base of tlie hind 

 wings of some Fagacia, and next the median vein of the same wing 

 in Dan. Plerippus, where androconia are not found. They do, how- 

 ever, sometimes occur in patches on the hind wings, as in the fetid next 

 the inner margin of the Equltes ; but, with the exception of the discal 

 spot of the Ephori, they seem to be present in all patches found on 

 the front wings ; occasionally forming the principal part of such patches, 

 as in the Callidryades, and again taking no part in the display. 

 Take, for example, the Dryades, where so many small black scales 

 are crowded against certain veins as to give them a thickened appear- 

 ance ; the androconia are also present in great numbers, but entirely 

 concealed ; only by removing the scales can even the tassels of their 

 long and slender blades be seen. Perhaps even more curious than 

 this is the arrangement by which all the androconia of the Equites and 

 Hesperides are tightly enclosed in a fold of the membrane ; it is not 

 impossible that this fold can be opened at vvill by the insect, and it 

 would then become conspicuous, and probably an attraction to the but- 

 terfly's mate ; but what possible advantage can there be in partially or 

 wholly concealed androconia, scattered separately over the wing ? In 

 some Adolescentes, they are exceedingly scarce, numbering not more 

 than one to a hundred scales, and the exposed surface of this one not 

 one-tenth that of the scales about it. One might search an hour with 

 a microscope over an unruffled wing and overlook it; indeed, it is as 

 the merest speck of dust in a dust heap. Does the siglit of these creat- 

 ures surpass our power of vision with the microscope ? The theory 

 of sexual selection proposed by Darwin appears to fail here, just where 

 it should aid us most. 



