THE HOUSE FLY 



73 



on the Rand than there might have been if the 61,943,000 

 had been left alive to propagate their species. The diseases 

 chiefly spread by flies are : enteric fever, diarrhoea, dysen- 

 tery, tuberculosis, and pneumonia. To take the case of 

 enteric first, the following comparative figures (for the 

 Municipality of Johannesburg all races) for the first four 

 months of 1913 and 1914 tell a tale calculated to convert 

 the most case-hardened sceptic into an implacable enemy 

 of the fly : 



1913. 1914. 



67 



13 



65 



20 



44 



10 



30 



4 



These figures give the following totals for the four 

 months : 



Cases. Deaths. 

 272 69 



1914 



Cases. Deaths. 

 157 26 



All the diseases mentioned compare as follows for the 

 months of March and April, 1913 and 1914, the figures 

 given being deaths in the Johannesburg Municipality for 

 all races : 



1913- 



March. April. 



Enteric . . . . 13 20 



Diarrhoea, &c. . . -53 33 



1914. 



March. April. 

 IO 4 



18 10 



Tuberculosis 

 Pneumonia 



35 



135 



37 

 101 



27 

 18 



21 

 21 



Totals . . . 236 191 73 56 



These figures represent for the two months a decrease in 



