CONTENTS vii 



CHAPTER VIII 



The senses of birds — Sight and its general high development — 

 Degree of perception of colonr-^j nfluence of colour, if any, 

 on courtship, and^the segregation ofjpecies — ^Perception of 

 the colour in various kinds of fobd — Smell, usually poorly 

 developed — ^Exceptions noted — ^Acuteness of hearing — Sense 

 of touch — Taste-perceptions . . . pp. 225-254 



CHAPTER IX 



The emotions of birds-^Mentality higher than is supposed, but 

 variable according to species or g'roups-^Strong- and weak- 

 minded birds — Intelligence and stupidity — The limitations 

 of instinct— Agression of the emotions and its relation to 

 courting d^play«—Love~ and ' sociability — Hatred and re- 

 .venge;— The police instinct — ^Monogamy, polygamy, and 

 polyandry — ^The problem of preferential mating pp. 255-280 



CHAPTER X 



Song and cries of birds^^Bird-language generally-^Extent to 

 which the notes are instinctively developed— ^The instinct of 

 mimicry — Species which can imitate human speech — ^Problem 

 of this ability and extent of exercise of the same — ^Possibility 

 of understanding of bird-language by man . pp. 281—292 



CHAPTER XI 



Weapons and fighting methods of birds — ^Their combats with 

 each other and with various natural enemies — Chief enemies 

 of birds — The passive resistance of birds to unfavourable 

 climate and surroundings — ^Natural defences — Perfection and 

 degeaieracy of plumage in this connection — Powder-coating of 

 some groups ...... pp. 293—302 



