fly is found "wherever man is found."

In the summer of 1898 a commission was appointed to investigate the
prevalence of typhoid fever in the United States Army Concentration
Camps. The following are some of the conclusions as reported by Dr.
Vaughan:

"FLIES UNDOUBTEDLY SERVED AS CARRIERS OF THE INFECTION

"My reasons for believing that flies were active in the
dissemination of typhoid may be stated as follows:

"_a._ Flies swarmed over infected fecal matter in the pits and then
visited and fed upon the food prepared for the soldiers at the mess
tents. In some instances where lime had recently been sprinkled
over the contents of the pits, flies with their feet whitened with
lime were seen walking over the food.

"_b._ Officers whose mess tents were protected by means of screens
suffered proportionately less from typhoid fever than did those
whose tents were not so protected.

"_c._ Typhoid fever gradually disappeared in the fall of 1898, with
the approach of cold weather, and the consequent disabling of the
fly.

"It is possible for the fly to carry the typhoid bacillus in two
ways. In the first place, fecal matter containing the typhoid 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 deposited
with its excrement."

In Dr. Daniel D. Jackson's report to the Merchants' Association of New
York on the "Pollution of New York Harbor as a Menace to the Health by
the Dissemination of Intestinal Diseases Through the Agency of the
Common House-fly," he shows graphically that the prevalence of typhoid
and other intestinal diseases is coincident with the prevalence of
flies, and that the greatest number of deaths from such diseases occurs
near the river front where the open or poorly constructed sewers scatter
the filth where the flies can feed on it, or along the wharves with
their inadequate accommodations and the resulting accumulation of filth.

FLIES AND OTHER DISEASES

Not only is the house-fly an important factor in the dissemination of
typhoid fever, but it has been definitely shown that it is capable of
transmitting several other serious diseases.

The evidence that flies carry and spread the deadly germs of cholera is
most conclusive. The germs may be carried on the body wher