. Guide leaflet. THE FOOT OF THE FLY Fig. 9 colonies of bacteria, each developed from a single germ plantedthere by the foot of the insect. Even more serious, perhaps, is thedanger that disease germs ingested by a fly from privy contents, orother infected material, may be voided in its excrement (fly specks)or in small droplets which are regurgitated by the insect. Experi-ments have shown that many kinds of disease germs may passthrough the intestines of the fly and be discharged in its excrement inan active and virulent state. K> INSECTS AND DISEASE The spoiling of foods may obviously be h
. Guide leaflet. THE FOOT OF THE FLY Fig. 9 colonies of bacteria, each developed from a single germ plantedthere by the foot of the insect. Even more serious, perhaps, is thedanger that disease germs ingested by a fly from privy contents, orother infected material, may be voided in its excrement (fly specks)or in small droplets which are regurgitated by the insect. Experi-ments have shown that many kinds of disease germs may passthrough the intestines of the fly and be discharged in its excrement inan active and virulent state. K> INSECTS AND DISEASE The spoiling of foods may obviously be hastened by ordinaryputrefactive germs introduced in such ways and, if the fly has beenfeeding upon human discharges (tuberculous sputum tor example, orthe contents of an outside closet used by an incipient typhoid case)specific human diseases may easily Fig. 10. BACTERIAL COLONIES DEVELOPED ON AN AGAR PLATE FROM GERMS PLANTED BY THE FEET OF A FLY WHICH WALKED OVER IT The number of microbes actually carried by flies varies greatlywith the general amount of filth in their surroundings. Studies madeby the New York Association for Improving the Condition of thePoor gave an average of 13,986 bacteria per fly (on the outer surfacesof its body) in clean localities, against 1,106,017 in dirty germs of typhoid fever and Asiatic cholera have been isolatedfrom the bodies of flies caught during epidemics of these diseases,and we have, in our museum of living bacteria at the AmericanMuseum, one strain of typhoid bacilli isolated in this way in thecourse of an outbreak in New Jersey. 17 AMERICAN MUSEUM GUIDE LEAFLETS It was the experience of the American troops in the SpanishWar which first forcibly called attention in this country to the dangerof the transmission of disease by flies. About one out of five of ourvolunteer soldiers
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectnatural, bookyear1901
