VI CONTENTS OF VOL. II. 



CHAPTER XTV. 



Birds — continued. 



Choice exerted by the female — Length of courtship — Unpaired 

 birds — Mental qualities and taste for the beautiful — Preference 

 or antipathy shewn by the female for particular males — Vari- 

 ability of birds — Variations sometimes abrupt — Laws of varia- 

 tion — Formation of ocelli — Gradations of character — Case of 

 Peacock, Argus pheasant, and Urosticte .. .. Page 99-153 



CHAPTEE XY. 



Birds — continued. 



Discussion why the males alone of some species, and both sexes 

 of other species, are brightly coloured — On sexually-limited 

 inheritance, as applied to various structures and to brightly- 

 coloured plumage — Nidification in relation to colour — Loss of 

 nuptial plumage during the winter .. .. .. .. 154-182 



CHAPTER XVI. 



Birds — concluded. 



The immature plumage in relation to the character of the plumage 

 in both sexes when adult — Six classes of cases — Sexual differ- 

 ences between the males of closely-allied or representative species 

 — The female assuming the characters of the male — Plumage of 

 the young in relation to the summer and winter plumage of the 

 adults — On the increase of beauty in the Birds of the World — 

 Protective colouring — Conspicuously-coloured birds — Novelty 

 appreciated — Summary of the four chapters on bkds 183-238 



