FLIES AND DISEASE 



By G. S. GRAHAM-SMITH, M.D. 



University Lecturer in Hygiene in the 



University of Cambridge. 



Most people probably regard Entomology, or 

 the study of insects, as an interesting hobby 

 followed by a few enthusiasts, who collect and 

 examine specimens, and recount fascinating tales 

 of the lives of many curious creatures. The earlier 

 students no doubt were actuated only by love for 

 their special subject, but for many years the 

 economic importance of insects has been recognized 

 and their habits have been studied in relation to 

 Agriculture, Forestry and many other subjects. 



Within the last forty years it has been shown 

 that insects, and especially flies, are important 

 agents in transmitting many serious and wide- 

 spread diseases both to men and to animals. 

 These discoveries are among the most important 

 in medical science within modern times, and have 

 led to far-reaching results. 



Once the causative microbe of a disease and its 

 mode of transmission are known, medical science 

 aims rather at the prevention of the scourge than 

 at the cure of individuals. Few appreciate the 



