PREFACE vii 



for much information and many suggestions, especially in 

 reference to the Chapters on Mammals and Birds. In fact, 

 without Dr. Gadow's advice and influence the book would 

 probably never have appeared. Dr. A. G. Butler, Mr. G. A. 

 Boulenger, F.R.S., and other members of the Staff did every- 

 thing in their power to facilitate my work at the Natural 

 History Museum. To these friends, and also to the artists 

 who have supplied the figures, Miss S. A. Willis, Mr. H. 

 Gronvold, and Mr. E. Knight, I have much pleasure in 

 recording my gratitude. 



Apart from these contributions the book consists very 

 largely of facts and descriptions taken from zoological litera- 

 ture, and few of the facts are based on my own observations. 

 It is, indeed, for the most part, a compilation, and the only 

 part of it for which the author is specially responsible is the 

 theory, which by many will probably be considered the least 

 valuable part. Such an opinion may be really correct. I 

 would only ask that the theory I have tried to elaborate shall 

 not be condemned and rejected merely because it is in 

 opposition to the views which have the sanction of authority. 

 Mr. Arthur Balfour has maintained, with much ingenuity, 

 that authority is the surest foundation of belief. However it 

 may be in matters theological, history proves that, in matters 

 intellectual, authority is merely an obstacle to progress, and 

 that the only sound foundation for belief is reason. I appeal 

 to reason, and if my arguments are ultimately proved to be 

 unsound, no one will regret their demolition less than myself. 



J. T. CUNNINGHAM. 



Penzance, Nov. 1899. 



