X LIFE AND WORKS OF COPE. 



search ; yet he himself discovered a number of his most im- 

 portant types. 



The fruits of the New Mexican journey appeared in 

 many bulletins and were finally collected in his second 

 great volume, " The Extinct Vertebrata obtained in New 

 Mexico by Parties of the Expedition of 1874.," Vol. IV., of the 

 Wheeler Survey. In 1874 appeared the first of his studies 

 upon the comparison of American and European horizons, 

 and of his contributions to the John Day fauna. His col- 

 lections were now accumulating so rapidly as to demand 

 more time for research and for many years he was fortunate 

 in securing the field services of Mr. C. H. Sternberg and 

 especially of Dr. J. 'L. Wortman. He continued to make 

 brief expeditions, among the last being his trip into the 

 Laramie region. ^ 



As. early as 1868 it may be said that he had laid the 

 foundations for five great lines of research, which he pur- 

 sued concurrently to the end. of his life ; these must, how- 

 ever, be followed separately to be understood and ap- 

 preciated. Only for comparatively brief intervals would 

 he pursue one line exclusively in order to complete some 

 special memoir, because his marvelous memory apparently 

 held and resumed the details of all the others with perfect 

 ease. 



Comparative Anatomy of the Fishes. 



Cope's work in Ichthyology would alone give him high 

 rank among zoologists. His friend. Professor Theodore 

 Gill* who has largely contributed to this section of the 

 biography, observed that it was among the Fishes that Cope 

 had rendered his greatest contributions. The same obser- 

 vation, however, has been made by Professor Baur in rela- 

 tion to the Amphibians, and by Scott and Osborn in refer- 

 ence to the fossil Mammalia. 



* Professor Gill has kindly allowed the writer to use the advance sheets of his 

 memorial address before the American Philosophical Society upon Professor Cope's 

 contributions to Ichthyology and Herpetology. 



