PURPOSE OF SONG 145 



sexual instinct. Is, then, the male's call an 

 indication of his readiness to yield to stimula- 

 tion ? Without a doubt it is an index of the 

 general physiological state which generates the 

 sexual impulse, without a doubt it denotes a 

 general preparedness to breed, but there is no 

 evidence to show that it denotes the degree of 

 ardour of the male at any particular moment, 

 and much that proves the contrary. So that 

 only by the female producing some special 

 sound which will attract the males that are 

 eager and bring them rapidly to the spot where 

 she happens to be, only thus is it possible to 

 insure the consummation of the sexual act. 

 This, it seems to me, is the purpose' of the 

 peculiar call of the female — a call which, so far 

 as biological interpretation is concerned, is just 

 as much a song as the melody of the Marsh- 

 Warbler — and its interest for us just now lies in 

 this, that here we have a special case in which 

 the sexes have separate territories, the female is 

 polyandrous, and the voice of the male is not 

 sufficient by itself to bring to pass the union 

 of the sexes ; and in which, consequently, if 

 the purpose of song be that of recognition, 

 we should expect to find, as we do find, that 

 the female had a distinct and penetrating 

 call. 



We now come to the question of " warning," 

 by no means the least important purpose of 

 song. I pointed out that one of the chief 

 differences between the call-notes and the song 

 was that the former were socially serviceable. 



