PREFACE IX 



whether of man or animals. Special attention has been 

 devoted to the modes of life of the more important insects 

 mentioned, to the manner in which the infection is transmitted 

 from one host to another, and also to any preventive measures 

 directed either against the flies or the infections themselves. 



Hitherto those interested in this subject have been obhged 

 to refer to entomological treatises for a knowledge of the 

 insects, while information concerning the infections trans- 

 mitted was only likely to be contained in medical or zoological 

 publications. Thus there is danger of the interdependence of 

 the two subjects being overlooked. The entomologist work- 

 ing in this field, without a more or less complete knowledge 

 of the factors influencing the transmission of any particular 

 malady, is liable to waste his efforts in unprofitable directions ; 

 whilst the Medical Officer or Administrator who is ignorant 

 of the main results of entomological research is equally handi- 

 capped in his attempts to combat the group of diseases under 

 discussion. It is hoped, therefore, that this book will appeal 

 to both classes and at the same time that its significance for 

 the prevention of disease will be apparent to that wider public 

 already indicated. 



The present volume together with that published by 

 Dr Graham-Smith in the same series^, covers the whole field 

 marked out by their general title, Flies and Disease. 



It may be useful to give the reader some idea of the general 

 arrangement of the subject matter that we have adopted. 

 After a short introduction, follow chapters on the structure 

 and classification of the Diptera, accompanied by a list of 

 biting flies known to transmit any infection. Each family, 

 including any such carriers of disease, is then dealt with 



"- Graham-Smith. Flies and Disease — N on-bloodsucking Flies. Cambridge 

 Public Health Series. 



