CHAPTER XII.

SECONDARY SEXUAL CHARACTERS OF FISHES, AMPHIBIANS, AND REPTILES.

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 conspicuous 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--Vocal organs. REPTILES: 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