204 SEXUAL selection: BIEDS. PartH. 



share in hatching the eggs; but the female likewise 

 attends to the youno'.^" 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 com- 

 mon cassowary {Casuarius galeatus) would 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 coloured ; and I am informed 

 by Mr. Bartlett that in the Zoological Gardens it is 

 certainlv the male alone who sits on the esrirs and takes 

 care of the young.^^ The female is said by Mr. T. W. 

 Wood ^^ to exhibit during the breeding-season a .most 

 pugnacious disposition ; and her wattles then become 

 enlarged and more brilliantly coloured. So again the 

 female of one of the emus (Dromoeus irroratus) is con- 

 siderably larger than the male, and she possesses a 

 slight top-knot, but is otherwise undistinguishable in 

 plumage. She appears, howevei", "to have greater 

 power, when angry " or otherwise excited, of erecting, 

 '• like a turkey-cock, the feathers of her neck and 



-0 For these several statemeuts, see Mr. Gould's ' Birds of Great 

 Britain.' Prof. Newton informs me tliat he has long been convinced, 

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

 the above-named sjDecies take either the wliole or a large share of the 

 duties of incubation, and that they " shew much greater devotion 

 " towards their young, when in danger, than do the femalet'." So it is, 

 as he informs me, with Limosa lapponica and some few other Waders, 

 in which the females are larger and have more strongly contrasted 

 colours than the males. 



21 The natives of Ceram (Wallace, 'Malay Archipelago,' vol. ii. p. 

 150) assert that the male and female sit alternately on the eggs ; but 

 this assertion, as Mr. Bartlett thinks, may be accounted fur by the 

 female visiting the nest to lay her eggs. 



22 ' The Student,' April, 1870, p. 124. 



