MARSH WABBLE B 



fluff out the feathers both on her breast and flanks. All these 

 antics are the special accompaniments of the sexual instinct, 

 and we can well imagine that it would be during this short 

 period — that is to say, previous to the actual discharge of the 

 sexual function — that the instinct would reach its maximum 

 development. Nor is it unreasonable to suppose that after 

 each discharge there should be a lessening in the intensity 

 of the instinct accompanied hj a decrease of the motor 

 reactions ; observation at least seems to show that this 

 really is the case. 



"Whether the female first selects a position for her nest and 

 then goes in search of material is difficult to determine, but 

 judging by her behaviour this does not appear to be her 

 method of procedure. For this is what occurs : she tears 

 off dead material of some kind, and flies from place to 

 place holding it in her bill. Making her way into some 

 thicket, she reappears, having left therein the material 

 she was carrying. For a time she is then lost to view, 

 but presently comes again into sight in the same vicinity 

 carrying a further supply of dead grass. This time, however, 

 she wanders about in uncertainty, and finally deposits it in an 

 entirely different situation, albeit only a few yards away. 

 This spirit of uncertainty ultimately deserts her ; a position is 

 found suitable to her requirements, and forthwith she sets 

 about her task in earnest, going repeatedly in search of 

 material, and upon returning therewith fixing it rapidly ; thus 

 the nest gradually begins to assume some shape. Eegarding 

 the psychology of the bird's behaviour it is perhaps wise to 

 say but little. Is the whole situation a conscious one, and, if 

 so, how far conscious ? Does the bird, that is to say, reflect 

 upon the possibilities of this position or of that, ultimately 

 come to a decision, and forthwith commence to build ? Or is 

 the mental process an altogether more simple affair, congenital 

 rather than individual, having its origin in some internal 

 impulse called forth by the sight of the requisite situation? 

 Personally I am inclined to the latter view. It is true that in 



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