SEXUAL SELECTION 471 



the larger and stronger males over their rivals during many 

 generations. The difference in size between the two sexes 

 is carried to an extreme point in several Australian species; 

 thus the male musk-duck (Biziura) and the male Gincloram- 

 pTvus cruralis (allied to our pipits) are by measurement 

 actually twice as large as their respective females." With 

 many other birds the females are larger than the males; 

 and, as formerly remarked, the explanation often given, 

 namely, that the females have most of the work in feed- 

 ing their young, will not suflSce. In some few cases, 

 as we shall hereafter see, the females apparently have 

 acquired their greater size and strength for the sake of 

 conquering other females and obtaining possession of the 

 males. 



The males of many gallinaceous birds, especially of the 

 polygamous kinds, are furnished with special weapons for 

 fighting with their rivals, namely, spurs, which can be used 

 with fearful effect. It has been recorded by a trustworthy 

 writer" that in Derbyshire a kite struck at a game-hen ac- 

 companied by her chickens, when the cock rushed to the 

 rescue, and drove his spur right through the eye and skull 

 of the aggressor. The spur was with difficulty drawn from 

 the skull, and as the kite, though dead, retained his grasp, 

 the two birds were firmly locked together; but the cock 

 when disentangled was very little injured. The invincible 

 courage of the game-cock is notorious: a gentleman who 

 long ago witnessed the brutal scene told me that a bird had 

 both its legs broken by some accident in the cock-pit, and 

 the owner laid a wager that if the legs could be spliced 

 so that the bird could stand upright he would continue 

 fighting. This was effected on the spot, and the bird fought 

 ■with undaunted courage until he received his death-stroke. 

 In Ceylon a closely allied, wild species, the Qallus Stanleyi, 

 is known to fight desperately "in defence of bis seraglio," 



'» Gould, "Handbook of Birds of Australia," vol. i. p. 395, vol. il. p. 383. 

 " Mr. Hewitt in the "Poultry Book by Tegetmeier," 1866, p. 13T. 



