CONTENTS. 



PART II. 



SEXUAL SELECTION— con^MiwecZ. 



CHAPTER XII. 



Secondary Sexual Characters of Fishes, Amphibians, 



AND KePTILES. 



Fishes : Courtsliip and battles of the males — Larger size of the 

 females — Males, bright colours and ornamental appendages ; 

 other strange characters — Colours and appendages acquired by 

 the males during the breeding-season alone — Fishes with both 

 sexes brilliantly coloured — Protective colours — The less con- 

 spicuous colours of the female cannot be accounted for on the 

 principle of protection — Male fishes building nests, and taking 

 charge of the ova and young. Amphibians : Differences in 

 structure and colour between the sexes — Yocal organs. Kep- 

 TiLES : Chelonians — Crocodiles — Snakes, colours in some cases 

 protective — Lizards, battles of — Ornamental appendages — 

 Strange differences in structure between the sexes — Colours — 

 Sexual diffeiences almost as great as with birds .. Page 1-37 



CHAPTER XIIJ. 



Secondary Sexual Characters of Birds. 



Sexual differences — Law of battle — Special weapons — Vocal 

 organs — Instrumental music — Love-antics and dances — Deco- 

 rations, permanent and seasonal — Double and single annual 

 moults — Display of ornaments by the males 38-98 



9 Q (\ 9 n. 



^ '^ o Ai> 



