BRITISH WARBLEES 



manner which differed but little from that of a few weeks 

 earlier in the season. I can now amplify this a little. The 

 Garden Warbler is not a particularly demonstrative bird ; 

 according to our emotional scale it occupies a position midway 

 between the two extremes, and we have placed it in a class by 

 itself. Two methods of expressing sexual emotion on the part 

 of the male are known to me, the more commonplace of the 

 two being that one in which the wings are partially extended, 

 and this is the attitude that is assumed by the female when 

 her nest is intruded upon, providing that the stimulus is 

 sufficiently strong to produce the necessary response. The 

 Willow Warbler is still less demonstrative, but both sexes 

 assume a peculiar attitude previous to coition, and this atti- 

 tude is again assumed by the female when excited about her 

 offspring. The Grasshopper Warbler is more demonstrative 

 than either of these two previous species. The male spreads 

 and waves its wings during sexual activity, and a similar 

 waving of the wings sometimes takes place in the case of both 

 sexes when excited about their young. In comparing these 

 two periods we must not lose sight of the fact that during 

 sexual activity the motor reactions reach their greatest 

 intensity in the male ; but during incubation, or whilst the 

 young still require the care of their parents, in the female ; 

 and as the female during sexual excitation shows traces of 

 those reactions common to the male, so the male when excited 

 about its young may affect attitudes similar to those of the 

 female. That the sexual and parental emotion should reach 

 the highest degree of intensity in the male and female 

 respectively is what we should anticipate since it appears to 

 be the rule throughout a considerable part of animal life. 

 Similarity of the organic symptoms in different emotions is 

 not unknown. Professor Lloyd Morgan refers to it as follows 1 : 

 " It would seem then, if there be any truth in the considera- 

 tions just hinted at rather than developed, that what is 



1 " Habit and Instinct," p. 201. 

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