i6o THE COURTSHIP OF ANIMALS 



a hut around a central column : a hut which may attain 

 to a height of as much as six or even eight feet, and the 

 walls of the pyramid thus raised are generally gaily 

 decorated with flowers and fruit. Around the central 

 a number of subsidiary huts are not infrequently found, 

 and in and out of these the birds pursue one another in 

 ecstasies of excitement. ^ ^ 



We have in these facts some extremely puzzling features, 

 which at present, at any rate, permit of no more than a 

 very rough analysis. Probably the whole of these bower- 

 building instincts have their origin in the habit, which the 

 males of so many birds exhibit, of carrying a leaf in the 

 beak when under the excitement of love-making. This 

 is suggestive of nest-building, and in many species this 

 is actually begun before the arrival of a female in the 

 breeding territory, while others build what are known as 

 " cock-nests " which are never used. Among the Bower- 

 birds these " cock-nests " have taken a new and more 

 elaborate form, and are placed on the ground instead of 

 in the trees, the normal site for the nest in all these birds. 

 Furthermore, stages in the evolution of such strange 

 fabrications can be found. These are furnished by the 

 Tooth-billed Bower-bird {Scenopaeetes dentirostris), the 

 Cat-bird {Aeluredus viridus), and the gorgeous Lawe's 

 Bird of Paradise {Parotia lazvest) — which is not perhaps 

 a Bird of Paradise. These build no bowers, but are 

 content with clearing a patch of ground, of about ten 

 feet in diameter, on which to disport themselves. But 

 while the " displays " of these birds closely resemble 

 one another, in the matter of coloration and ornament 

 they present the most striking contrasts. 



