148 A HISTORY OF BIRDS 



reaches an acute stage and the wild dance is in full swing once 

 more ! 



Although in the earlier part of the chapter it was implied 

 that the strange antics of which examples have just been cited 

 were performed in the presence of the opposite sex, this appears 

 by no means to be a general rule. It does not seem to be 

 known, for example, whether the females of the Paradise -birds 

 are witnesses, at a respectful distance, of the strange dances 

 in which their respective lords engage, or whether these are in- 

 dulged in by the males alone for their own delight. But with 

 some species at any rate, as will be shown presently, the presence 

 of the female seems to be all-important. 



Since, in the light of modern discovery, all birds appear to 

 indulge in antics more or less remarkable during the season of 

 courtship, it is obviously impossible to do more than select some 

 of the more important of such displays, and the further accom- 

 paniments which in a large number of instances are to be met 

 with. 



So far we have cited cases where this accompaniment takes 

 the form of brilliant and highly specialised plumage, using the 

 Sparrow as a foil, so to speak, inasmuch as here, though the antics 

 are grotesque enough, the plumage presents no striking features. 



But there are a number of species which at this critical 

 period develop special organs, or for the nonce make temporary 

 use of existing organs, apparently for the sole purpose of en- 

 hancing their suit with the opposite sex. Anatomical changes, 

 in short, of a more or less complex character, make their ap- 

 pearance at this time, and disappear, or at any rate remain 

 dormant, for the rest of the year. The most remarkable of 

 these organs are those which take the form of wind-bags, or 

 inflatable sacs, and they are used solely in displays of a peace- 

 able character. But there are some species which, during the 

 season of courtship, become extremely pugnacious, and among 

 these many are provided with formidable weapons of offence, 

 weapons which, unlike the antlers of the stag, are permanent. 

 On the other hand, there are a few species which become more 

 markedly social and indulge in the most curious dances. 

 These several phases will now be discussed. 



The displays which depend on the use of wind-bags shall 

 be taken first. And of such displays the most familiar is that 



