INTRODUCTION 5 



This investigation has been the most complete organised study 

 of the fly as a vector of micro-organisms that has yet been 

 made, and in the subsequent pages I have made full use of the 

 contents of the five reports which have appeared n]) to the time 

 of writing ^ 



Mv own studies were beyun in 1U05, at wliieh time no com- 

 plete studv of the anatomy or cle\elopment of the house-fly had 

 been matle,. and the gradual realisation of the economic status 

 of the fly made such a study not only desirable but necessary in 

 view of our profound ignorance on the subject. A preliminary 

 account of the life-history was published in 1906. In the 

 following year (1907) a detailed account of the anatomy of the 

 fly was published, this being the first part of a monograph on 

 the structure, development and bionomics of Musca domestica. 

 The second part of this monograph was published in 1908 and 

 gave an account of the breeding-habits, development and bio- 

 nomics of the larva. The concluding part of the work was 

 published in 1909, and in it were described the bionomics of the 

 house-fly, its allies and parasites and its relation to human disease. 



In additi(m to the investigations which I have continued 

 since that date, other investigators have added to our know- 

 ledge of the bionomics of the house-fly with the result that, 

 although our knowledge of the insect cannot be said to be com- 

 plete, we have decreased our previous unfortunate ignorance of 

 the commonest insect to a marked degi'ee and have furnished 

 a solid basis for further studies along particular lines, and infor- 

 mation necessary to a consideration of the means of control and 

 prevention. 



Description of Musca domestica. 



Musca domestica was first described in 1758 by Linnaeus in 



his Systema Naturae: his description is as follows: 



"Antennis plumatis pilosa nigra, thorace lineis 5 ol).soletis abdominc 

 iiitidulo tessellato: minor. Habitat in Europe domibus, etiam Americ-ae- 

 Larvae in simo equinae. Pupae parallele cubantes." 



It was more fully described by Fabricius in his Genera 

 Insectorum. 



' A Further Report, No. 6, has appeared since the above was written. 





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