ORIGIN OF SONG 163 



it is along these lines that the evolution of 

 the voice has proceeded. 



In all probability there was a time when 

 vocal expression was limited to primitive social 

 and family cries which would be called into play 

 with special force during times of excitement, 

 more particularly during the sexual season 

 which is the period of maximum emotional 

 excitement. But the excitement would express 

 itself; in all the congenital modes of behaviour 

 peculiar to the season, and thus the repetition 

 of these cries would become associated with 

 combat, with extravagant feats of flight, and 

 with other forms of motor response. Now the 

 more emotional individuals would be the more 

 pugnacious, and all the more likely therefore to 

 secure territory and so to procreate their kind ; 

 and, being of an excitable disposition, they 

 would at the same time be the more vociferous. 

 Hence variations of the hereditary tendency to 

 vocal expression, even though in themselves 

 they were not of survival value, would be 

 fostered and preserved, so long as they were not 

 harmful, in virtue of their association with 

 pugnacity. But if, instead of being neutral, 

 they helped to further the biological end of 

 combat, the relationship between the voice and 

 pugnacity would be of a mutually beneficial 

 kind ; and those individuals in which variation 

 in both directions happened to coincide, would 

 have a better chance of success in the attain- 

 ment of reproduction. 



A territorial system, closely corresponding 



M 



