X PREFACE 



amongst us with schemes for our regeneration, among 

 which " Sex-problems " are made to occupy a very con- 

 spicuous place. But no good can come of their cogita- 

 tions so long as they fail to realize the springs of behaviour 

 in this regard. The facts herein set down will, it is hoped, 

 help much towards this end. 



My labours in the preparation of these pages have been 

 materially lightened by the help and counsel of many 

 friends. To them I desire now to record my very grateful 

 thanks. More especially am I indebted to my friends 

 Mr. H. Eliot Howard, Professor Lloyd Morgan and Mr. 

 John Cooke. 



I must also thank those who have contributed towards 

 the illustrations which enliven these pages. The delight- 

 ful Frontispiece, and many of the plates scattered through 

 this work, I owe to the generosity of Messrs. Rowland 

 Ward, Limited. The excellent rendering of the Birds of 

 Paradise adapted in part from the work of Mr. G. E. 

 Lodge and the late J. G. Keulemans, and partly drawn 

 from specimens in the British Museum, is the work of 

 Mr. Roland Green. The very difficult, and less fascinating, 

 technical figures I owe to the skill of Mr. Philip Whelpley. 

 The wonderful photographs illustrating the " Display '* 

 of the Sun-bittern and the Kagu were taken by my friend 

 Mr. D. Seth-Smith. 



Finally I have to thank Mr. Roger Ingpen for the 

 immense amount of trouble which he has taken in seeing 

 these pages through the press. 



W. P. Pycraft. 



October, 191 3. 



