PAET II. 
SEXUAL SELECTION— 
CHAPTEE XII. 
SecojsDaky Sexual Characteks of Fishes, Amphibians, 
AND Keptiles. 
Fishes ; Courtship 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. Pep- 
tiles : Chelonians — Crocodiles — Snakes, colours in some cases 
protective — Lizards, battles of — Ornamental appendages — 
Strange differences in structure between the sexes — Colours — 
Sexual differences almost as great as with birds .. Page 1-37 
CHAPTEE XIII. 
Secondary Sexual Characters of Birds. 
Sexual differences — Law of battle — Special weapons — Yocal 
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 
