246 University of California Publicaiions in Zoology [Vol. 13 



II. Acknowledgments 



To Professor C. A. Kofoid, of the University of California, under 

 whose direct supervision this work was carried on, the writer is 

 especially grateful for his very valuable advice and suggestions, 

 and for his aid in the preparation of this paper. 



The writer is indebted to Dr. Joseph Grinnell, of the Museum of 

 Vertebrate Zoology of the University of California, for free use of 

 the specimens in the museum. He also wishes to express his appre- 

 ciation of the generous supply of material for study by the American 

 Museum of Natural History in New York, and the United States 

 National Museum in "Washington. Grateful acknowledgments are 

 due to Dr. W. T. Hornaday and Mr. Lee S. Crandall of the New 

 York Zoological Park for saving and sending molted feathers which 

 could not readily be procured from museum specimens. 



Other material was procured from the Memorial Museum in 

 Golden Gate Park, San Francisco, through Mr. W. G. Blunt of 

 the Natural History department. The writer is further indebted 

 to the California Academ}^ of Sciences in San Francisco, for the use 

 of its collection of water birds, and to the Bentley Ostrich Farm of 

 Oakland, California, for the supply of ostrich feathers, and assist- 

 ance in the examination of living birds. 



III. Historical 



The first thorough and reliable work on feathers was done by 

 Nitzsch, a German ornithologist. This work was edited and pub- 

 lished by Burmeister, and later translated into English and published 

 in the Transactions of the Ray Society in 1876, a few of the miscon- 

 ceptions of the original author being rectified in the process. 



This work, though dealing primarily with pterylography, contains 

 the first approximately accurate account of the structure of feathers 

 to "be found in the whole literature of the subject, and may justly 

 stand as a masterpiece. Following Nitzsch, a number of works on 

 the development and structure of feathers appeared, among which 

 may be mentioned especially Clement (1876), Studer (1878), Jeffries 

 .(1884), Klee (1886), Davies (1889), and Strong (1902); and, more 

 particularly on structure, Wray (1887b), Pycraft (1893), and 

 Mascha (1904). Many other less general but highly valuable papers 



