ASA GRAY 217 



cms, with no opportunity of comparison with the types. It is easy 

 to understand how incorrect determinations would be made, how 

 these would be perpetuated, and how descriptions would finally 

 be changed to suit the wrongly named plants. In Gray's first 

 work on the Flora he discovered that many American plants were 

 masquerading under false names; but to discover the real plant 

 to which a name belonged could only be done by examining the 

 type specimen. He felt that no more of the Flora should be pub- 

 lished until these types had been examined. Hence, although 

 accepting the Michigan appointment, he asked for and obtained 

 leave of absence to visit Europe, agreeing to serve the university 

 at the same time by buying books for the library. 



In November, 1838, he sailed, and entered upon those personal 

 relations with the most distinguished European botanists that 

 continued with increasing intimacy until his death. His letters 

 show that he met almost every distinguished worker in systematic 

 botany, and their strong personal liking and admiration for him 

 is still freely expressed in the great herbaria he visited. In addition 

 to the herbaria of England and Scotland, he visited those of Paris, 

 Lyons, Geneva, Munich, Berlin, Halle, Hamburg, and Vienna. 

 In all he made six more or less prolonged visits to Europe and put 

 the identity of the older described American plants upon a sure 

 basis. 



Upon Gray's return from his first trip to Europe, in 1839, his 

 leave of absence was extended by the University of Michigan. In 

 fact he never entered upon his duties there, the furlough merging 

 into his appointment at Harvard College. In the spring of 1842, 

 he visited Mr. B. D. Greene in Boston, and while there met 

 President Quincy of Harvard. Soon afterwards he was elected 

 to the Fisher Professorship of Natural History, and continued in 

 this position for the rest of his life. The large opportunity had 

 come at last, and it was at Harvard that Gray made his great repu- 

 tation, entering upon his duties there as teacher, author, and inves- 

 tigator with an enthusiasm and an ability that soon made Cam- 

 bridge the center of botanical instruction and investigation in 

 America. He was a most prolific writer, but a complete list of 



