THE RELATIONS OF THE SEXES i6i 



for the retention of, their females. But there is some evidence to 

 show that they not seldom occur as the outcome of displays at 

 preconcerted meeting-places such as have already been described 

 in these pages as occurring among Grouse and Ruffs for example. 



Certain members of the Plover tribe, and certain Anserine 

 birds have, however, developed spurs of a very formidable 

 character on the wings. 



Among the Plover tribe the best example is that furnished 

 by the Egyptian Spur-winged Plover (Hoploptefus). These 

 birds fight, after the manner of our common English Lapwing, 

 by turning suddenly in the air and striking with the wings- 

 In the case of the formidably armed Egyptian bird the result 

 is often fatal. In our own birds a fatal result is rarely the 

 case, since slightly swollen knobs take the place of spurs. In 

 Hoplopterus and in the Jacana this spur arises from the base 

 of the thumb, but in the Spur-winged Goose {Plectropterus) it is 

 borne by the radial carpal bone, while in the Screamers 

 {Palamedea and Chaund) there are two spurs on each wing, one 

 at each end of the metacarpus. That these formidable weapons 

 have been developed for the purposes of offence and defence 

 there can be no doubt, but there are no detailed records as to 

 the frequency of such encounters. 



No less remarkable is the form of the weapon which has 

 been developed by another Plover, one of the Jacanas {Meto- 

 pidius). In this bird the radius has been broadened out from 

 its middle onwards, in the form of a flat plate, or blade, but the 

 manner in which this is used seems to be unknown. 



The dearth of facts with regard to the time and place of the 

 use of these weapons is deplorable ; but this is partly to be 

 explained by the fact that these birds live in regions little visited 

 by observing naturalists, and when encountered by collectors 

 are promptly shot, life-histories having for them no interest. 



We may pass now to a brief outline of the more important 

 facts which have been recorded with regard to the peaceful arts 

 of dancing and music among birds. 



As touching dancing among birds. This curious exercise 

 is practised by many different birds belonging to widely different 

 groups, and in parts of the world remote from one another. 

 One of the Manakins — small South American birds belonging 

 to the Family Pipridse — and perhaps others, is an expert dancer, 



