SOME OF THE "LOWER ORDERS" 203 



impregnation has taken place. Hence males with 

 defective scent-detecting powers inevitably fail to leave 

 offspring. 



Selection, then, here lies between males of the 

 most active scent-detecting powers, and not between 

 those of the most brilliant colours. Nevertheless, both 

 males and females — where the females are winged — 

 exhibit a remarkably beautiful coloration, and this is 

 especially true of the Kentish Glory, wherein both sexes 

 wear a resplendent dress. That of the male — which is 

 much smaller than the female — differs in that the fore- 

 wings are darker, but bear the same pattern as in the 

 female, while the hind-wings are chestnut-red instead 

 of cream colour as in the female. If this scent-factor 

 has replaced colour as an inciting agent to pairing, then 

 these Moths should be of sombre hues. That such is 

 not the case seems sufficient to show that the colour is 

 not due to Sexual Selection, for it is highly improbable 

 that scent and colour are both of equal importance, and 

 this being so, one would expect to find the negligible 

 factor eHminated. 



The existence, then, of bright colours in this and 

 other species in like case, seems to show that it 

 has nothing to do with Sexual Selection, directly at 

 any rate. The males having assembled, their presence 

 is probably communicated to the female by the charac- 

 teristic male odour, which is never of the same penetrating 

 quality as that of the female. There is no need that it 

 should possess this, for the females never seek their mates. 

 The successful male, where several rivals are competing, 

 is probably not simply the strongest, but he who also 

 disperses the right odour necessary to provoke the 

 pairing response. These illustrations furnished by the 



