— 16 — 



filth, and as an adult fly it feeds on all kinds of decaying and fecal matter, as 

 well as the sweets and liquids of the dining table. Its feet and proboscis are ad- 

 mirably adapted for carrying those bacterial germs that cause typhoid fever, 

 cholera, dysentery, diarrhoea, tuberculosis, etc. Moreover, it has been shown 

 that typhoid bacilli swallowed by the house-fly when it feeds on and crawls over 

 contaminated substances survive the passage of the alimentary canal, so that "fly- 

 specks" may contain many active typhoid germs. 



It has been shown also that several other species of flies that frequent houses 

 may also convey typhoid bacilli. The "little house-fly". (Fanna canicula ri s), 

 the Latrine-fly (Fannia scalaris), the blow-fly (Calliphora erythrocephala), 

 Muscina stabiilans, the cluster-fly (Pollenia rudis), and the stable-fly (Stomoxys 

 calcitrans)have all been found guilty and precautions should be taken to guard 

 against their presence. 



The charges proven against the house-fly as an active agent in disseminating 

 not only typhoid fever but also cholera, dysentery and tuberculosis are over- 

 whelming. This insect pest should therefore be banished from our midst. If we 

 do not care for our own health we shou'ld at least protect the helpless children 

 who are perhaps the greatest suft'erers. 



(For further particulars the excellent works of Doctors Hewitt and Howard 

 should be consulted). 



Stable-Fly and Infantile Paralysis. 



The stable-fly (Stomoxys ca'lcitrans), the horn-fly (Haematobia serrata), 

 gad-flies (Tabanus and Chrysops), and the black-fly (Simulium) have both pierc- 

 ing and sucking beaks and are true blood-suckers. As such they are liable to 

 introduce virus into the human blood. 



Through the investigations of Doctors Brues, Rosenau and Sheppard of 

 Massachusetts and of Doctors Anderson and Frost of Washington, published in 

 1912 and 1913, there is fairly conclusive evidence that infantile paralysis is mainly 

 transmitted by the bites of the stable-fly. The reasons for suspecting the relation- 

 ship are (Brues) : — 



"i. — The blood-sucking habits of the adult fly suit it for the transfer of 



virus present in the blood. 

 "2. — The seasonal abundance of the fly is very closely correlated with the 

 incidence of the disease, rising rapidly during the summer and reach- 

 ing a maximum in July and August; then slowly declining in Septem- 

 ber and October. 

 "3. — The geographical distribution of the fly is, so far as can be ascertained, 

 wider, or at least co-extensive with that of poliomyelitis (infantile 

 paralysis). 

 "4. — Stomoxys is distinctly more abundant under rural conditions than in 



cities and thickly populated areas. 

 "5. — While the disease spreads over districts quickly and in an erratic way 

 it often appears to follow along lines of travel, and it is known that 

 Stomoxys will often follow horses for long distances along highways. 

 "6. — In a surprisingly large number of cases it appeared that the children 

 affected had been in the habit of frequenting places where Stomoxys 

 is particularly abundant, i. e., about stables, barn-yards, etc." 



