158 THE HOUSE FLY— DISEASE CARRIER 



practically everywhere in midsummer, both as to the 

 swarms of flies and the lax care of excreta among 

 small children, it is impossible to avoid the conclusion 

 that flies bear a very important relation to the number 

 of cases and therefore to the number of deaths. 



Nuttall and Jepson have abstracted a number of pub- 

 lished papers on this subject, with the following re- 

 sults : 



'The relation of flies to the spread of summer diar- 

 rhea has aroused special interest of recent years. Fraser 

 (1902), referring to epidemic diarrhea in Portsmouth, 

 states that 'on visiting the houses in question I find 

 that in all, almost without exception, the occupants 

 have suffered from a perfect plague of flies. They told 

 me every article of food is covered at once with flies. 

 * * * I repeat that to this, and this alone, I at- 

 tribute the diarrhea in the Goldsmith Avenue district.' 



''Nash (1903, p. 128) pointed out that there were 

 twenty-three cases of the disease in Southend-on-Sea in 

 1 90 1, whilst there were none in the summer of 1902. 

 M. domestica was completely absent in the wet summer 

 of 1902, but appeared in September of the same year; 

 coincident therewith there occurred thirteen cases of 

 infantile diarrhea. Nash (1904) considers that M. 

 domestica is the chief carrier of diarrhea-causing bac- 

 teria. 



"Newsholme (1903, p. 21) has expressed the opin- 

 ion that food in the houses of the poor can scarcely 

 escape fecal infection. 'The sugar used in sweetening 

 milk is often black with flies, which may have come 



