TO DANIEL ELMER SALMON 



LARGELY THROUGH WHOSE LABORS THERE WAS ES- 

 TABLISHED IN THE UNITED STATES DEPARTMENT OF 

 AGRICULTURE THE BUREAU OF ANIMAL INDUSTRY 

 WHICH HAS MADE POSSIBLE EXTENSIVE INVESTIGA- 

 TIONS INTO THE NATURE OF EPIZOOTIC DISEASES 

 IN AMERICA AND WHO FOR TWENTY-ONE YEARS 

 DIRECTED THESE INVESTIGATIONS 



THIS VOLUME IS DEDICATED. 



. >-u F» /■» i~> o 



