LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Biological Survey, 

 ^yasJungton, D. C, July 17, 1907. 

 Sir: I have the honor to transmit herewith for publication as Bul- 

 letin Xo. 29 of the Biological Survey a report of progress on the work 

 in relation to the cotton boll weevil, b}'^ xVrthur H. Howell. 



As a result of investigations during the years 1906 and 1907, our 

 knowledge of the part birds play in restricting the ravages of the pest 

 was considerably increased, and a number of additional species were 

 found to feed upon the Aveevil. Practical suggestions are made in 

 the bulletin for increasing the numbers of swallows breeding in the 

 cotton districts, swallows having been ascertained to l)e among the 

 most important enemies of the pest. 



Respectfully, H. W. Henshaw, 



Acting Chief, Biological Survey. 

 Hon. James Wilson, 



Secretary of Agriculture. 

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