THE HOUSE FLY 41 



One of the most significant publications in recent years was issued 

 in 1908 by the Merchants' Association of New York City on the pol- 

 lution of New York Harbor. 10 The fecal matter of the sewerage dis- 

 charge into the water attracted swarms of flies, many of which were 

 caught in traps placed on the piers and afterward examined in the 

 laboratory for bacteria. One individual fly carried more than 100,000 

 fecal bacteria. The same publication contains a chart sbowing the 

 location where each individual death from intestinal diseases occurred 

 during the season, and they were by far the most prevalent in the 

 downtown districts near the water front, where sewerage and fly con- 

 ditions are worst. Infantile diarrhoea was the cause of many of these 

 deaths, and the author of this publication, Dr. Jackson, attributes 

 much of the infection to the agency of flies. 



"Washburn only last year 11 investigated a typhoid outbreak, and 

 found flies chiefly responsible for the spread of this disease on the Iron 

 Range of Minnesota. Many other cases might be cited. 



Local Conditions to be Avoided 



Many persons go from their homes in the cities to spend their vaca- 

 tions at shore resorts or mountain camps, and are soon taken sick with 

 typhoid. The imperfect sanitary conditions at many of these places 

 make it hard to prevent the spread of the disease if a case of it occurs, 

 and where a large number of persons are brought together from differ- 

 ent localities there is always danger. 



Large gangs of laborers in quarries, lumber camps and on construc- 

 tion work are, on account of carelessness and ignorance, liable to suffer 

 from the spread of typhoid fever by flies, and what has been said of 

 typhoid would doubtless be equally true of cholera and dysentery. 



In looking about our cities and towns for breeding places of the 

 house, fly, what do we find ? In many stables manure is allowed to ac- 

 cumulate untreated as long as there is room for it, then it is carted 

 away to the suburbs and piled upon the land. Carloads of manure 

 from the large cities are drawn through our towns and allowed to 

 stand on sidings for several days, perhaps, before reaching their destina- 

 tion and being unloaded. Streets are often so filthy as to attract flies, 

 and when cleaned, the sweepings are dumped on vacant lots or drawn 

 into the parks for fertilizer and allowed to remain in heaps sev- 

 eral months. In many streets water closets are not installed, and 

 uncared-for dry closets are still in use. All of these conditions are 

 favorable for the breeding of flies, and we should remember that in 



10 D. ~D. Jackson, "Pollution of New York Harbor," Merchants' Associa- 

 tion of New York, July, 1908. 



11 F. L. Washburn, Eeport of State Entomologist of Minnesota, 1909-1910, 

 p. 135. See also Popular Science Monthly, August, 1911, p. 137. 



