84 THE SCOTTISH NATURALIST 



2. Her emotional responsiveness to display in the drake 



may result in selection of that drake whose display 

 is the direct or immediate stimulus in arousing the 

 pairing instinct. 



3. She may select from amongst her possible mates the 



one whose external attributes possess prepotent 

 attraction. 



1. Observation goes to show that pairing depends 

 immediately upon subjective nervous impulse, whether purely 

 spontaneous, or brought to fruition by external stimulus in 

 the form of the drake's display, or otherwise. If choice of 

 mate is no more than " accidental," then on the mating- 

 impulse being acquired, the female should mate with the 

 nearest male, indifferent to individual display or other 

 externals ; that is to say, proximity should be the all-sufficient 

 qualification in the drake, and all else be superfluous. The 

 observable facts do not bear this out. It may not be easy to 

 speak with absolute conviction, but the strong impression 

 received is that choice does not necessarily fall upon any 

 proximate drake. It is true that the female does not extend 

 her field of operations beyond a certain radius ; on the other 

 hand, it is a common sight to see her push aside intervening 

 birds in order to reach a more distant one, and during court- 

 ship of a particular male she frequently intermits her pursuit 

 to repulse others who may follow. Such instances, and they 

 are of frequent occurrence, do not tempt one to regard her 

 choice as accidental. 



2. Similar considerations incline one to reject the second 

 hypothesis (as self-sufficient) but with much less confidence. 

 The essential question here is : what relation does display 

 bear to courtship? 



Love-play in the Mallard presents two phases previous to 

 pairing: (1) display; emotional expression taking the form 

 of certain elaborate bodily movements, common to both 

 sexes, although more highly developed in the male ; (2) 

 courtship; emotional expression which takes a vigorous and 

 characteristic form in the female, while the corresponding 

 behaviour of the male is passive. The drake's behaviour is 

 thus relatively active in the first phase, and relatively passive 



