INTRODUCTION 3 



relating to their connection with disease have only been made 

 within the last few years. 



In 1895 Howard in the United States began to study the 

 bionomics of the house-fly, and, soon recognizing its potentiality 

 as a carrier of disease, has continued his observations up to 

 the present time. The investigations relating to the outbreaks 

 of typhoid fever in the military camps during the Spanish- 

 American and South African wars further attracted attention to 

 the subject in England and America. The work of Hewitt, 

 Newstead and Austen, isolated observations by various writers 

 at home and abroad, and the investigations carried out for the 

 Local Government Board have added considerably to our know- 

 ledge and have helped to definitely establish some important facts. 



Articles dealing with the disease carrying possibilities of the 

 house-fly have been published recently in large numbers, and 

 interest in the subject has spread to all parts of the world, so 

 that we may hope within a few years to be in possession of accu- 

 rate information relating to the connection between house-flies 

 and the spread of various infectious diseases. 



" In the United States a very active campaign is being 

 waged on all sides against the house-fly, as it is considered to 

 be a serious factor in the transmission of zymotic diseases, and 

 as being synonymous with insanitary conditions. No small 

 credit for this activity is due to the primary and continued 

 efforts of Dr L. O. Howard, the Entomologist of the United 

 States Department of Agriculture. As illustrating the popular 

 feeling with regard to the fly campaign in the United States it 

 may be mentioned that the Mayor of the capital of one of the 

 States was elected almost solely on the strong stand which he 

 had taken in advocating anti-fly measures. This sudden change 

 of opinion, which has already affected and is reflected in the 

 bye-laws relating to public health matters, is of more than 

 ordinary interest, and is fully in keeping with the spirit of the 

 age." (Hewitt, 1912, p. 4.) Howard (191 1, p. xvi) has in fact 

 proposed the name ' typhoid fly ' as a substitute for the name 

 'house-fly,' now in general use. He admits that "strictly 

 speaking the term ' typhoid fly ' is open to some objection as 

 conveying the erroneous idea that this fly is solely responsible 



