viii Preface 



mainly from the lack of continuity and the overlapping 

 which such papers would present when printed together 

 under one cover, I have still determined upon this course. 

 It was my first intention to write a general introduction 

 to evolution, — an exposition and criticism of the great 

 theories, — and indeed such an intention is embodied in 

 a contract with the publishers of the ' Science Series ' ; but 

 it now becomes necessary to make that undertaking a 

 separate affair, since this volume makes no pretence to 

 completeness from such a point of view. I may add that 

 that purpose is indeed, to my mind, excellently served 

 by Professor H. W. Conn's able and readable book, The 

 Method of Evolution, along with which students may take 

 up also with profit the work Problems of Evolution, by 

 F. W. Headley. 



This change of plan once determined upon, it seemed 

 highly desirable that the original papers of Professors Os- 

 born and Lloyd Morgan should be liberally drawn upon, 

 both in the interest of cooperation — from the first most 

 cordial and friendly — and in that of advantage to our com- 

 mon views ; for their positions were reached from quite 

 different Hnes of approach, and the theory gains very 

 much from this diversity of presentation. I accordingly 

 secured their consent to my making liberal quotations 

 from their papers ; and, as I proceeded, it occurred to me 

 that instead of making detached citations here and there 

 the reader would profit more by longer quotations, — and, 

 indeed, that the authorities quoted would thus be much 

 more adequately presented. Hence the full citations 

 from these authorities in Appendix A.^ This method once 



1 The fulness of my personal recognition of them, as well as of another, 

 is expressed, though still inadequately, in the dedication of this volume. At 

 the same time, these writers are, of course, in no way implicated in the views 

 of the book, except as their own statements are quoted. 



