LETTER OF TRANSMITTAL. 



United States Department of Agriculture, 



Bureau of Biological Survey, 



Washington, D. C, January 28, 1909. 

 Sir : I have the honor to transmit herewith a report on the Brown 

 Rat in the United States, by Prof. David E. Lantz, and to recommend 

 its publication as Bulletin No. 33 of the Biological Survey. 



The rat is believed to be the worst mammalian pest known to 

 man. Not only does it damage property to the extent of many mil- 

 lions of dollars annually, but to this pecuniary loss must be added 

 the still greater harm it inflicts by the dissemination of the dreaded 

 plague and other diseases. Boards of health of many maritime cities 

 in this and other countries are now engaged in an active campaign 

 against rats, but thus far without very gratifying success. In Japan, 

 where the Government is awake to the seriousness of existing con- 

 ditions, the number of rats destroyed annually, according to Pro- 

 fessor Kitasato, varies "from several hundred thousand to a million. 

 Nevertheless at the present day no appreciable diminution in the num- 

 ber of rodents can be noticed. Reproduction keeps pace with de- 

 struction, so that we are at a loss to know how to proceed. " In order 

 to secure effective cooperation it is important to impress on the 

 public the need of concerted and sustained effort, and particularly 

 the necessity of depriving these noxious animals of the lavish supply 

 of food and shelter now unwittingly furnished them. In this con- 

 nection it is believed that the present bulletin will prove helpful. 

 Respectfully, 



C. Hart Merriam, 



Chief Biological Survey. 

 Hon. James Wilson, 



Secretary of Agriculture. 



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