546 HOWARD 



germ may adhere to the fly and be mechanically transported. 

 In the second place, it is possible that the typhoid bacillus may 

 be carried in the digestive organs of the fly and may be depos- 

 ited with its excrement." 



There were also many important conclusions which bear upon 

 the fly question. For example, it was shown that every regi- 

 ment 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 became epidemic both in small encampmefits 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 pytho- 

 genic theor}^ ^ were not supported by the investigations of the com- 

 mission but the doctrine of the specific origin of fever was con- 

 firnred. The conclusion was reached that the fever is dissemi- 

 nated by the transference of the excretions of an infected indi- 

 vidual to the alimentary canals of others and that a man infected 

 with typhoid fever may scatter the infection in 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 one-fifth of the soldiers in the 

 national encampments in the United States during that summer 

 developed this disease, while more than 80 per cent, of the total 

 deaths were caused by typhoid. 



In the work carried on by the writer and under his super- 

 vision in the investigation of the insect fauna of human excre- 

 ment which is here described, he was assisted by Messrs. D. 

 W. Coquillett, E. A. Schwarz, W. II. Ashmead, F. C. Pratt, 

 Nathan Banks, and Aug. Busck, of his office force. Mr. Co- 

 quillett is responsible for the determination of all of the species 



' 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 maj' become the active 

 agent in the causation of typhoid fever. 



