EVOLUTION 



BY 



PATRICK GEDDES 



PROFESSOR OF BOTANY, ST. ANDREWS UNIVERSITY 

 AND 



J. ARTHUR THOMSON 



REGIUS PROFESSOR OF NATURAL HISTORY, ABERDEEN 

 UNIVERSITY 



Joint Authors of " Ihe Evolution of ?#," etc. 



NEW YORK 

 HENRY HOLT AND COMPANY 



LONDON 

 WILLIAMS AND NORGATE 



