204 THE COURTSHIP OF ANIMALS 



scent-hunting, scent-dispersing males and females are 

 of the highest importance to students of the Sexual 

 Selection theory, for they seem to show conclusively that 

 coloration plays at any rate but a minor part therein. 

 The importance of the scent-detecting organs is shown 

 in the very different types of antennae which obtain 

 between male and female Moths, those of the male taking 

 the form of huge feather-like structures, as in some 

 Saturniidae, and far exceeding those of the female in 

 size. 



The methods of pairing which obtain among Butter- 

 flies and Moths, it is not surprising to find, are very 

 different ; for whereas in the former it takes place on 

 the wing, in the latter the female is always in a resting 

 position. Where the females are winged, long flights 

 are often taken for the purpose of depositing and dis- 

 tributing the eggs : the flightless forms make no such 

 excursions. A few, as in the case of some of the Psychidce^ 

 are not only wingless, but limbless and maggot-Hke. 

 They never leave the chrysalis case, but deposit their 

 eggs inside it. Though there is undoubtedly much that 

 is wonderful about the mating of these scent-distributing 

 species, the history of the Moths of the genus Acentrophus 

 is more wonderful and more mysterious still. For the 

 females are aquatic. The males may sometimes be 

 found in crowds fluttering over the surface of large but 

 shallow sheets of water. The females, which are wing- 

 less, come to the surface and, like sirens, draw the males 

 under water, where coupling takes place ; after which 

 they probably immediately die. But how do they 

 discover their submerged mates ? The escape from the 

 water of any odour which the females may possess seems 

 well nigh impossible. 



