THE PRIMARY FACTORS 



OF 





ORGANIC EVOLUTION 



BY 



E. D. COPE, PH. D. 



MEMBER OF THE U. S. NATIONAL ACADEMY OF SCIENCES', PROFESSOR 



OF ZOOLOGY AND COMPARATIVE ANATOMY IN THE 



UNIVERSITY OF PENNSYLVANIA 



CHICAGO 



THE OPEN COURT PUBLISHING COMPANY 

 (LONDON: 17 JOHNSON'S COURT, FLEET ST., E. C.) 



1896 



