1898.] NATURAL SCIENCES OF PHILADELPHIA. 491 



of birds themselves. It must be remembered in this connection that 

 even as early as Aristotelian time, birds were classified into groups, 

 aud Pliny, adhering to much that had been done five centuries 

 before him, selected only the very obvious characters of the feet for 

 the purpose, which threw all the birds known to him, into three 

 divisions, of which a Hawk, a Hen, and a Goose were respectively 

 representative. Thus were associated the Ducks and Cormorants, — 

 the Rails and Robins, — and this is what the feet did. Ornithology 

 was placed upon a scientific basis about the middle of the seventeenth 

 century through the labours of Willughby and Ray. They were 

 the first to use the two main divisions of Land and Water birds, and 

 in subdividing, both the bills and feet were used as classificatory 

 characters. For the most part Linnseus followed Ray, and in doing 

 so kept many birds in taxonomic juxtaposition where the affinity 

 was quite remote. Mergansers and Albatrosses were kept together, 

 as were Divers and Gulls, — and so much for what bills and feet did 

 in those days. Improvement over early authors was very evident, 

 however, and many palpable errors were rectified. From such 

 beginnings the science has grown up, authors and classifiers being 

 more and more numerous with each succeeding generation. Some 

 used one set of characters and some another, but it is to be distinctly 

 noticed that the previous taxonomic schemes have always influenced 

 their followers in later years. Merrem, who in 1812, was perhaps the 

 first to publish a systematic arrangement of the groups of birds, was 

 doubtless influenced by all that had been accomplished prior to his 

 time, as the work of Nitzsch in pterylography, Cuvier in structure, 

 and Linnams and Ray in a number of external characters. His 

 scheme was a solid contribution to the classification of birds, based 

 as it was upon a variety of anatomical characters, as those drawn 

 from the sternum, those from the feathers, those from the osseous 

 system, and those from other parts, as the bills and feet. In fact 

 Merrem took a long step in the direction of the truth, or rather in 

 the discovery of the true relationships of birds in nature. 



De Blainville quickly followed Merrem, and again rearranged the 

 avian scheme of classification, fascinated as he was by the characters 

 presented on the part of the body of the sternum. In some direc- 

 tions further advancement was evidenced, however, and this advance- 

 ment later on was powerfully increased by the labors of Nitzsch 

 who brought into play the arterial system, the song-muscles, the 

 nasal glands, and other morphological features. 



