PREFACE vii 



fruitful cause of the discredit which in certain minds 

 attaches to speculative morphology. Although the 

 distinction I have attempted to draw may be arbitrary 

 in some cases, my endeavour has been to show that 

 as long as we confine our speculations within the 

 limits of the great animal phyla or groups, compara- 

 tive morphology has supplied us with a number of 

 securely founded generalizations of real value, but 

 that when we attempt to unravel the inter-relation- 

 ships of the phyla to one another our speculations 

 are really valueless. 



The study of the past is interesting for its own 

 sake, and also for the doubtful rays of prophetic light 

 it may throw into the obscurity of the future. This 

 is my excuse for the last chapter, which is intended 

 to apply some of the principal ideas gathered in the 

 course of our argument to the present condition of 

 mankind, to his future prospects and to the influence 

 which he exerts upon other forms of life. 



The sources from which my facts have been 

 gleaned are certainly many, but perhaps the leading 

 ideas have been taken less from books than from the 

 traditional teaching which I have received in the 

 Oxford school of Morphology. 



G. S. 



NEW COLLEGE, OXFORD. 

 July 1911. 



