DUCKS AND EVOLUTION 3 



studied, for they are not only living, but accessible ; 

 the semi-wader at the beginning of the series, the 

 Australian Magpie-Goose"^ (Anseranas semipalmata) 

 is no rarity, and I have spent much time in study- 

 ing a full-winged specimen at Kew, while the 

 habits of many others of the family exemplifying the 

 gradations I have mentioned are accessible either to 

 direct observation or to any one who can look up 

 bird literature. 



In fact, the Duck famUy is one of the most inter- 

 esting of all animal groups for any one interested 

 in biological problems, owing to the wide distribu- 

 tion of its members, their essential and obvious 

 alliance combined with equally striking diflFerences 

 — some obviously adaptive, others more inexpHcable 

 —and I shall have a good deal to say about them 

 in the course of this book, especially as they are 

 familiar exhibits in many public parks, and thus 

 available for everybody's observation. 



The availability of birds, as a class, for study gives 

 them, in fact, an importance in the study of animal 

 habits which fairly outweighs their insignificance 

 from the morphological point of view ; and I 

 personally have never admitted that the study of 

 structure is more important than that of habit, 

 considering that it only acquires its pre-eminence 

 from the fact of demanding a professional training 

 which is the prerogative of a few only. When one 

 comes to think of it, we durselves only surpass the 

 other mammals in virtue of our habits, being 

 structurally simply monkeys on our hind legs ; yet 



