414 THE DESCENT OF MAN. 



tiau goose {Chenalopex mgyptiacus) has only "bare obtuse 

 knobs/' and these probably show us the first steps by which 

 true spurs have been developed in other species. In the 

 spur- winged goose (Plectropterus gambensis) the males 

 have much larger spurs than the females; and they use 

 them, as I am informed by Mr. Bartlett, in fighting to- 

 gether, so that, in this case, the wing-spurs serve as sexual 

 weapons ; but according to Livingstone, they are chiefiy 

 used in the defense of the young. The Palamedea (fig. 38) 

 is armed with a pair of spurs on each wing; and these are 

 such formidable weapons that a single blow has been known 

 to drive a dog howling away. But it does not appear that 

 the spurs in this case, or in that of some of the spur- 

 winged rails, are larger in the male than in the female.* 

 In certain plovers, however, the wing-spurs must be con- 

 sidered as a sexual character. Thus in the male of our 

 common peewit ( Variellus cristatus) the tubercle on tlie 

 shoulder of the wing becomes more prominent during the 

 breeding-season, and the males fight together. In some 

 species of Lobivanellus a similar tubercle becomes developed 

 during the breeding-season '^ into a short, horny spur.'" In 

 the Australian L. lobatus both sexes have spurs, but these 

 are much larger in the males than in the females. In an 

 allied bird, the Hoplopterus armatus, the spurs do not in- 

 crease in size during the breeding-season; but these birds 

 have been seen in Egypt to fi^ht together, in the same man- 

 ner as our peewits, by turning suddenly in the air and 

 striking sideways at each other, sometimes with fatal results. 

 Thus also they drive away other enemies, f 



The season of love is that of battle; but the males of 

 some birds, as of the game-fowl and ruff, and even the 

 young males of the wild turkey and grousej are ready to 



*For the Egyptian goose, see Macgillivray, " British Birds," vol. 

 iv, p. 639. For Plectropterus, "Livingstone's Travels," p. 254 

 For Palamedea, Brehm's " Thierleben," B. iv, s. 740. See also on 

 this bird Azara, "Voyages dans TAmerique merid.," torn, iv, 1809, 

 pp. 179, 253. 



f See, on our peewit, Mr. R. Carr in "Land and Water," Aug, 8, 

 1868, p. 46. In regard to Lobivanellus, see Jerdon's "Birds of 

 India," vol. iil p. 647, and Gould's "Hand-book of Birds of Austra 

 lia," vol. ii, p. 220. For the Holopterus. see Mr. Allen in the 

 "Ibis,' vol. V, 1863. p. 156. 



|Au4uboji, "Ornith. Biography," vol. ii, p. 49^; vol. i, pp. 4-13. 



