R. STEWART MACDOUGALL. The Common House-fly (Alusca do- 



mestica). Trans. High, and Agric. Soc. Scottland, vol. XXI 

 PP- I35-I74. 



Although several species of fly are found in our houses, this is 

 by far the commonest. 



Dangers due to the Housefly. Domesticated animals are plagued 

 by these flies when the flies are present in great numbers; but it 

 is as a menace to the health of human beings that we would de- 

 nounce tne house-fly and argue for a campaign against it. 



That danger may attend the presence of the house-fly is clear 

 from much evidence that these insects can and do carry infection 

 : and comestibles. It is not pleasant to reflect that these 

 house-flies may have come directly from filth or garbage, and that 

 germs of disease attached to their hairs or voided in their excre- 

 ment can be deposited on meat, or confectionery, or fruit, or eata- 

 bles generally, or be washed off into milk, where the germs may 

 multiply and be the cause of disease. 



Such infective matter carried to milk-that not uncommon grave 

 -can in the summer-time, when flies are abundant, be re- 

 sponsible for the prevalence of summer diarrhoea in children so 

 baneful in result. A high percentage of the deaths of children from 

 infantile diarrhoea is due to infection conveyed by house-flies. 



The spread of typhoid fever has in well authenticated cases 

 been proved to be due to the carriage of the bacillus of typhoid 

 by house-flies. The bacillus of consumption can also be carried 

 fly, not only externally attached to hairs on its body but 

 also internally, the bacilli after being voided not having lost their 

 virulence. 



Experimentally, too, it has been shown that where flies were 

 d on cultures of the cholera germ, the germs were found up to 

 our days later in the intestines of the flies and in their excrement. 

 The germ of anthrax may also be carried. 



Protective Measures. Protect exposed comestibles by means of 

 gauze. 



Do away with exposed heaps of stable manure, and arrange 

 that such manure be in closed receptacles. 



Howard found that chloride of lime applied to manure piles 

 lestroyed the maggots. He recommends the regular cleanina out 



stables, and each time that a day or two's accumulation is 



