The Wilson Bulletin 



It a quarterly journal devoted to 

 the study of the birds as we find 

 them in the fields and woods. 



It is particularly concerned about the study 

 of the whole life-history of each species, 

 and about the effects of advancing civiliza- 

 tion upon the lives of all birds. It urges 

 the great importance of making a census 

 of our bird population for the purpose 

 of determining accurately what change 

 there may be in numbers due to changing 

 conditions. It is the official organ of the 

 Wilson Ornithological Club, which num- 

 bers among its members some of the 

 most prominent American ornithologists. 

 Carefully selected illustrations appear in 

 each number. 



IS cents a number; 50 cents a year 



Address 



LYNDS JONES, Editor, Oberlin, Ohio. 



Perfection Bird Houses 



FOR THE 



Purple 

 Martin 



We build them. 

 T went y-f i ve 

 years experience 

 in the study of 

 these fine birds, 

 and success in their colonization, has 

 taught us the exact requirements of 

 the House Martins and enables us to 

 construct ideal boxes for their use. 



Illustrated Booklet 10 cents 



The J. Warren Jacobs Bird House Co. 

 WAYNESBURG, PA. 



DEOPLE talk about a 

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 when one stops to think how 

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Send for circulars illustrat- 

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PRISM is/a little maga- 

 zine of lens information. 

 Send for copy. 



OUR NAME OS A PHOTOGRAPHIC LESS. 

 FIELD GLASS. M ICROSCOPE. LABOR ATORY 

 APPARATUS. SCIENTIFIC OR ENGINEERING 

 INSTRUMENT IS OUR GUARANTEE. 



Bausctj &?omb Optical (So. 



CARL ZEISS, Jena GEO. N. SAEGMULLER 



SAN FRANCISCO 

 WASHINGTON 



BOSTON \ I / LOHDO N 

 CHICAGO \1/ FRANKFORT 



offices: Y^B-L 



NEW YORK \ZjS 



ROCHESTER, X. Y. 



