THE RELATIONS OF THE SEXES 147 



By way of contrast with the several displays just described 

 it would be hard to find a more striking illustration than that 

 afforded by the great Bird of Paradise {Paradisea apoda), inas- 

 much as here the display is associated with rivalry between a 

 number of individuals. For much of our knowledge on this 

 matter we have to depend upon the descriptions of natives, 

 collected on the spot by Mr. Alfred Russel Wallace, but 

 happily this has now been supplemented by observations made 

 by Mr. Ogilvie Grant on a captive in the Gardens of the 

 Zoological Society of London. 



It appears then, that during the period of courtship these 

 birds at frequent intervals gather together, up to the number of 

 twenty, on certain of the forest trees of the Aru Islands, selected 

 apparently on account of the fact that they have an immense 

 head of spreading branches, and large but scattered le^ives, 

 thus affording plenty of space for the revels, which take the 

 form of " Sacaleli," or dancing parties. 



By the time the ball opens the birds appear to have worked 

 themselves up to a state of great excitement, and each com- 

 mences his performance with quivering wings and a loud cry — - 

 " waa ! waa ! waa ! waa ! " Then the wings are suddenh' held out 

 in a semi-vertical position on either side of the body, the tail is 

 bent forward under the branch, and with a quick shuffle of the 

 plumage, the side plumes are erected, forming an arched cascade 

 over the back, meeting one another in the middle line. With 

 every muscle tense the bird will remain in this attitude from ten 

 to twenty seconds, slightly quivering his wings, and from time 

 to time hitching up his long plumes, which are raised somewhat 

 above the level of the top of the head. 



Then a second stage commences. Each bird, seemingly 

 gone mad, commences to dance and hop wildly backwards and 

 forwards along the bough, and with head bent down, wings fully 

 extended horizontally, and side plumes erected to their utmost, 

 he utters loud harsh cries — " ca ! ca ! ca ! ca ! " 



For some seconds he remains in a sort of ecstasy, rubbing 

 his beak on the bough, and occasionally glancing backwards 

 below his feet with the back fully arched. Then, the climax 

 passed, he reverts once more to the first and more erect stage 

 of the display, when the paroxysm either gradually subsides, or 

 is renewed, and after an interval of about half a minute again 



