INFLUENCE OF THE FEMALE ll5 



admitted that emotion adds to the efficacy of 

 behaviour, and this is the view of Professor 

 Lloyd Morgan. " Whatever may be the exact 

 psychological nature of the emotions, it may be 

 regarded," he says, " as certain that they intro- 

 duce into the conscious situation elements which 

 contribute not a little to the energy of behaviour. 

 They are important conditions to vigorous and 

 sustained conation." Therefore, if it be true 

 that the female raises the emotional tone of the 

 male, the result will be an increased flow of 

 energy into all the specific modes of behaviour 

 connected with reproduction, amongst which 

 those directly concerned in the securing and 

 defence of the territory will receive their share ; 

 so that instead of a progressive weakening of 

 just those elements in the situation which make 

 for success, the level of their efficiency will be 

 maintained as a result of such reinforcement. 

 But the female becomes intolerant of her own 

 sex when she has discovered a male ready to 

 breed, and, later, assists her mate in resisting 

 intrusion ; and by raising her emotional tone, he 

 may be the means of furthering more strenuous 

 behaviour on her part. Each member of the 

 pair would in this way contribute towards the 

 energy of behaviour of its mate, and hence add 

 indirectly to the security of the territory. 



It may be well to illustrate the foregoing 

 remarks. Suppose that there is a small piece of 

 woodland barely sufficient to hold three pairs of 

 Willow- Warblers, and suppose that the male and 

 female in the middle territory did not respond to 



