4 PROCEEDINGS OF THE 



identify his specimens with some established species failed. 

 This caution and the absence of the craze for new species so 

 prevalent of late years accounts for the stability of most of the 

 names for which he is responsible. 



Coues says: " He was patient and laborious in the technic of 

 his art, and full of book-learning in the history of his subject; 

 with the result that the Cassinian period [of American Orni- 

 thology] , largely by the work of Cassin himself, is marked by its 

 bookishness, by its breadth and scope in ornitliology at large, 

 and by the first decided change since Audubon in the aspect of 

 the classification and nomenclature of the birds of our country. 

 The Cassinian period marks the culmination of the changes 

 that wrought the fall of the Audubonian sceptre in all that re- 

 lates to the technicalities of the science, and consequently repre- 

 sents the beginning of a new epoch." 



Cassin worked entirely at the Academy, spending his even- 

 ings, Sundays and holidays in the Museum when business de- 

 manded his attention at other times. During the last years 

 nt his active work he is described as occupying the back room 

 jf the library in the old Academy building at Broad and 

 Sansom streets, where mounted birds and ornithological books 

 were gathered together in large numbers, and where they re- 

 mained accumulating dust until his work upon them was com- 

 pleted, guarded meanwhile by an unwritten though well under- 

 stood law of "hands off." His jealousy of others in the same 

 lield who might be about the Academj', and his prior claim 

 upon the pri^dleges of the Wilson collection evidently accounted 

 for the absolute monopoly in matters ornithological at the in- 

 stitution which he maintained throughout his career. 



Notwithstanding the fact that it is the technical systematic 

 side that is emphasized in all Cassin' s writings, we would be 

 wrong to assume that he was solely a " closet naturalist." The 

 claims of business and the opportunities offered by the Museum 

 undoubtedly deterred him from taking extended trips or even 

 ilevoting much time to field work in the vicinity of his home. 

 The love of nature was ever present, however, and a large part 

 of his earlier years must evidently have been occupied in gain- 

 ing that thorough knowledge of the birds of Pennsylvania and 



