?o BIRD LIFE GLIMPSES 



there had come to be two structures for two pur- 

 poses, that only would have been subjected to 

 modification which stood in need of it. For the 

 rest, as incubation and courtship are very different 

 things, one might expect the architecture in relation 

 to them to be of a very different kind. For these 

 reasons, and having watched rooks at their nests in 

 the winter, and the breeding habits of some other 

 birds, I think it possible (i) that the bower has 

 grown out of the nest, and (2) that the sexual 

 activities of which it is, as it were, the focus, were 

 once displayed about the nest itself. On the whole, 

 however though I suggest this as a possible explana- 

 tion it is perhaps more likely that the cleared arena 

 where so many birds meet for the purposes of court- 

 ship as, e.g. the blackcock, capercailzie, ruff, argus 

 pheasant, cock-of-the-rock, &c. &c. is the start- 

 ing-point from which the bower-birds have proceeded, 

 especially as one species of the family has not got so 

 very much farther than this, even now. 



Rooks, then, to leave speculation and return to 

 fact, are swayed, even in winter, by love as well as 

 by hunger those two great forces which, as Schiller 

 tells us, rule the world between them. They wake, 

 presumably, hungry ; yet, before they can have fed 

 much, make shift to spend a little while on the 

 scene of their domestic blisses. Hunger then looks 

 after them till an hour or so before evening, when 

 they return to their rookeries, and love takes up the 

 ball for as long as daylight lasts. And so, with birds 

 as men 



" Erfiillt sich der Getriebe 



Durch Hunger und durch Liebe." 



