118 THE HOUSE FLY—DISEASE CARRIER 
organs of the fly and may be deposited with its excre¬ 
ment.” 
There were many other important conclusions which 
bear upon the fly question. For example, it was shown 
that every regiment in the United States service in 
1898 developed typhoid fever, nearly all of them within 
eight weeks after assembling in camps. It not only 
appeared in every regiment in the service, but it be¬ 
came epidemic both in small encampments of not more 
than one regiment and in the larger ones consisting of 
one or more corps. All encampments located in the 
Northern as well as in the Southern States exhibited 
typhoid in epidemic form. The miasmatic theory of 
the origin of typhoid fever and the pythogenic theory* 
were not supported by the investigations of the com¬ 
mission, but the doctrine of the specific origin of fever 
was confirmed. The conclusion was reached that the fe¬ 
ver is disseminated by the transference of the excretions 
of an infected individual to the alimentary canals of 
others and that a man infected with typhoid fever may 
scatter the infection through every latrine or regiment 
before the disease is recognized in himself, while germs 
may be found in the excrement for a long time after 
the apparent complete recovery of the patient. Infected 
water was not an important factor in the spread of 
typhoid in the national encampments of 1898, but about 
*This theory is founded upon the belief that the colon germ 
may undergo a ripening process by means of which its virulence 
is so increased and altered that it may be converted into the 
typhoid bacillus or at least may become the active agent in the 
causation of typhoid fever. 
