PRINCIPLES 



OF 



ECONOMIC ZOOLOGY 



BY 



L. S. DAUGHERTY, M.S., Ph.D. 



PROFESSOR OF ZOOLOGY, STATE NORMAL SCHOOL, KIRKSVILLE, MO. 

 AND 



M. C. DAUGHERTY 



AUTHOR WITH JACKSON OF "AGRICULTURE THROUGH THE LABORATORV 

 AND SCHOOL garden" 



IVITH 301 ILLUSTRATIONS 



PHILADELPHIA AND LONDON 



W. B. SAUNDERS COMPANY 



1915 



