CAMBRIDGE PUBLIC HEALTH SERIES 



UNDER THE EDITORSHIP OF 

 G. S. Graham -Smith, M.D. and J. E. Purvis, M.A. 



Ihiiversity Lecturer in Hygiene and University Lecturer in Chemistry 

 Secretary to the Sub-Syndicate for and Physics in their application 

 Tropical Medicine to Hygiene and Preventive Medi- 



cine, and Secretary to the State 

 Medicine Syndicate 



FLIES IN RELATION TO DISEASE 



NON-BLOODSUCKING FLIES 



