10 



FARMERS BULLETIN 851. 



voided, not only in the excrement of the fly, but also in small droplets 

 of regurgitated matter which have been called "vomit spots." 

 When we realize that flies frequent and feed upon the most filthy 



substances (it may be the excreta 

 of tjT^hoid or dysentery patients 

 or the discharges of one suffering 

 from tuberculosis), and that sub- 

 sequently they may contammate 

 human foods with their feet or ex-, 

 creta or vomit spots, the necessity 

 and importance of house-fly control 

 is clear. 



In army camps, in mining camps, 

 and in great 2)ublic works, where 

 large numbers of men are brought 

 together for a longer or shorter time, 

 there is seldom the proper care of 

 excreta, and the carriage of t^^phoid 

 germs from the latrines and privies 

 to food b}^ flies is common and 

 often results in epidemics of t^-phoid 

 fever. 



And such carriage of typhoid is 

 ])y no means confined to great tem- 

 porally camps. In farmhouses in 

 small communities, and even in 

 badly cared for portions of large 

 cities, tjT^hoid germs are carried 

 from excrement to food l)y flics, 

 and the proper supervision and 

 treatment of the breedmg places 

 of the house fly become most im- 

 portant elements in the prevention 

 of t}T)hoid. 



In the same way other intesti- 

 nal germ diseases, such as Asiatic 

 cholera, dysentery, and infantile 

 diarrhea, are aU so carried. Then- 

 is strong circumstantial evidence 

 also that tuberculosis, anthrax, 

 yaws, ophthalmia, smallpox, tropical sore, and the eggs of parasitic 

 worms may be and are carried in this wa}'. Actual laboratory proof 

 exists in the case of a number of these diseases, and where lacking is 

 replaced by circumstantial evidence amomiting almost to certaintyo 



Fig. 12.— The house centipede {Sail Ujera forceps) 

 Adult. Natural size. (Marlatt.) 



