162 THE HOUSE FLY— DISEASE CARRIER 



weeks ending July 27th and August 3d, and also that 

 the deaths from intestinal diseases rose above the nor- 

 mal at the same time at which flies became prevalent, 

 culminated at the same high point, and fell off with a 

 slight lag at the time of the gradual falling off of the 

 prevalence of the insects. 



Tuberculosis 



The typhoid fly also possesses importance as a dis- 

 seminator of the bacilli of tuberculosis. We have seen 

 on an earlier page the method by which the adult fly 

 feeds upon sputa. They are attracted to all sputa and 

 feed upon them with avidity. One of the writer's as- 

 sistants (himself a tuberculous patient) more than ten 

 years ago wrote him from a Colorado resort telling of 

 the lax care of the sputa of the consumptives, and 

 stating that he had seen numbers of patients sitting 

 upon a veranda and occasionally expectorating over the 

 railing upon the ground where numerous flies had con- 

 gregated and were feeding. The significant part of the 

 letter, however, was the statement that the open win- 

 dows of the kitchen were not many feet away from this 

 particular portion of the veranda. 



It is not difficult to understand the danger of the 

 transfer of the causative organisms of the diseases of 

 the alimentary tract by flies, but in regard to tubercu- 

 losis of the lungs, it should be stated that the observa- 

 tions of Nicolas and Descas (quoted by Cobb) indi- 

 cated that fasting dogs fed with bouillon containing 

 quantities of bacilli were shortly after examined and 



