544 THE DESCENT OF MAN. 



law that secondary sexual characters are often widely dif- 

 ferent in closely allied forms, though it is a very rare cir- 

 cumstance when such diiferences relate to the female sex. 

 The young of both sexes of R. bengalensis in their first 

 plumage are stiid to resemble the mature male.* There is 

 also reason to believe that the male undertakes the duty of 

 incubation, for Mr. Swinhoe \ found the females before the 

 close of the summer associated in flocks, as occurs with the 

 females of the turnix. 



The females of Phalaropusfnlicarius and P. hyperhoreus 

 are larger, and in their summer plumage " more gayly 

 attired than the males.'' But the difference in color between 

 the sexes is far from conspicuous. According to Prof. Steen- 

 strup, the male alone of P. fulicarins undertakes the duty of 

 incubation; this is likewise shown by the state of his 

 breast-feathers during the breeding-season. The female of 

 the dotterel plover (Eudromias morineUus) is larger than 

 the male, and has the red and black tints on the lower sur- 

 face, the white crescent on the breast and the stripes over 

 the eyes more strongly pronounced. The male also takes 

 at least a share in hatching the eggs; but the female like- 

 wise attends to the young. J I have not been able to dis- 

 cover whether with these species the young resemble the 

 adult males more closely than the adult females; for the 

 comparison is somewhat difficult to make on account of the 

 double moult. 



Turning now to the ostrich order ; the male of the 

 common c^is&owoxy {Casurius galeatus) vfo\\\d be thought 

 by any one to be the female, from his smaller size and from 

 the appendages and naked skin about his head being much 

 less brightly colored; and I am informed by Mr. Bartlett 

 that in the Zoological Gardens it is certainly the male alone 



*'*The Indian Field," Sept., 1858, p. 8. 



t " Ibis," 1866, p. 298. 



JFor these several statements, see Mr. Gould's "Birds of Great 

 Britain." Prof. Newton informs me that he has long been convinced, 

 from his own observations and from those of others, that the males 

 of the above-named species take either the whole or a large share of 

 the duties of incubation, and that they "show much greater devo- 

 tion toward their young, when in danger, than do the females." So 

 it is, as he informs me, with Limosa Inpponka and some few other 

 waders, in which the females are larger and have more strongly con- 

 trasted colors than the males. 



