PREFACE TO THE FIRST EDITION 



The title of this book might more appropriately, if not 

 more concisely, have been "The Animal Mind as Deduced 

 from Experimental Evidence." For the facts set forth in 

 the following pages are very largely the results of the ex- 

 perimental method in comparative psychology. Thus 

 many aspects of the animal mind, to the investigation of 

 which experiment either has not yet been applied or is per- 

 haps not adapted, are left wholly unconsidered. This limi- 

 tation of the scope of the book is a consequence of its aim 

 to supply what I have felt to be a chief need of compara- 

 tive psychology at the present time. Although the science 

 is still in its formative stage, the mass of experimental ma- 

 terial that has been accumulating from the researches of 

 physiologists and psychologists is already great, and is also 

 for the most part inaccessible to the ordinary student, being 

 widely scattered and to a considerable extent published in 

 journals which the average college library does not contain. 

 While we have books on animal instincts and on the inter- 

 pretation of animal behavior, we have no book which ade- 

 quately presents the simple facts. 



Probably no bibliography seems to one who carefully 

 examines it entirely consistent in what it includes and what 

 it excludes. Certainly the one upon which this book is 

 based contains inconsistencies. The design has been to ex- 

 clude works bearing only upon general physiology, upon the 

 morphology of the nervous system and sense organs, or upon 

 the nature of animal instinct as such, and to include those 

 which bear upon the topics mentioned in the chapter head- 

 ings. Within these limits, the collection of references upon 



