THE IBIS. 



NEW SERIES. 



No. XI. JULY 1867. 



XVI. — The Distribution and Migrations of North American 

 Birds*. By Spencer F. Baird^ Assist. Sec. Smithsonian 

 Institution, For. Mem. Z.S. 



[Abstract of a memoir presented to the National Academy of Sciences, 

 January 1865.] 



It is well known to all students of Natural History that the 

 zoology of America or the New World is very different from 

 that of the Old World, and that with these two grand divisions 

 there are, in each, various subdivisions of greater or less impor- 

 tance. To Dr. Sclater f is perhaps due the merit of having 

 been the first clearly to define the " Regions " into which the 

 animal life of the terrestrial globe, the birds especially, may be 

 divided, and to point out appi'oximately their relative magnitude 

 and boundaries as well as their comparative richness in species 

 of birds. Some of his details have been corrected and im- 

 proved by Mr. Wallace J ; but the conclusions of Dr. Sclater are 

 in the main those which have received the support of most 

 naturalists of the present day, and his details will ever mark an 

 era in the science of zoological geography. 



* From the ' American Journal of Science and Arts/ vol. xli. January, 

 March, and May 1866. 



t Journal of Proceedings of the Linnean Society : Zoology, ii. 1858, 

 p. 130. (Read June 16, 1857.) X Ibis, 1859, p. 449. 



N. S. — VOL. Ill, T 



