142 THE ZOOLOGIST. 



nest, and, moreover, as said before, something much resembling a 

 Peewit's nest is by such movements actually made. Taking all 

 this together, we have here, as it seems to me, an indication of 

 some such origin of nest-building as that which I have imagined. 



As this theory supposes some relation between the nest and 

 the place where pairing takes place — that the one in fact gradually 

 becomes the other— it would be interesting to ascertain whether 

 birds that make their nests in a place which is out of character 

 with their ordinary habits, pair here or amidst their more usual 

 surroundings. For instance, if the Nightjar, a most aerial and 

 arboreal species, were nevertheless to pair habitually upon the 

 ground, this would be a somewhat striking fact. I cannot 

 affirm that it does so. Nevertheless, it is my impression 

 that upon one occasion — which I have recorded in a former 

 paper — I but just missed seeing the pairing of two that I was 

 watching upon the ground and in the near vicinity of the nest. 

 Since then I have seen one pursue another in an obviously 

 amorous or "nuptial" flight from the top of a tree to the ground 

 where it (the pursued bird) settled. The nocturnal habits of 

 this species are, however, a great difficulty in the way of obser- 

 vations of this kind. 



The male Wheatear indulges, during the breeding season, in 

 very extraordinary movements of a more or less frenzied nature, 

 and, in watching these, one cannot but be struck by the predilec- 

 tion which seems shown for some natural hollow in the ground, 

 within or over which such movements take place. I have given 

 elsewhere * a full account of these actions as exhibited by two 

 rival birds for the greater part of an afternoon, and I will only 

 quote here a few lines which give that incident of the bits of 

 grass which I have already alluded to. I have, it is true, 

 suggested a symbolical explanation, but, however that may be — 

 nor does, perhaps, the one supposition preclude the other — I 

 think what I witnessed shows that a bird may seize something 

 and bring it to a certain spot whilst in a state of violent nervous 

 excitement, and when the intention of building a nest seems 

 pretty well excluded as a cause of such action.! If this be so, 

 then, at least, some part of the difficulty which we might feel in 

 supposing a process now become so elaborate, and (in some cases 



* In my recent work, ' Bird Watching,' chapter iv. 



\ Compare, also, what I have quoted in regard to the Ostrich. 



