METHODS OF RESEARCH 301 



adopted have met with complete success and in 

 many instances the results have been most beneficial, 

 but in others they have been less satisfactory than 

 was anticipated. Even unsatisfactory results may 

 be valuable, for they direct attention to factors 

 in the spread of the disease which have been 

 insufficiently studied and thus lead to researches, 

 which may eventually so increase our knowledge of 

 the processes involved in the production and trans- 

 mission of the disease as to render its complete 

 control practicable. 



