12 THE HOUSE FLY—DISEASE CARRIER 
foul with excremental products, if they were kept moist 
and at a suitable temperature. He also reared adult 
flies from decaying vegetables thrown away as kitchen 
refuse, and on such fruits as bananas, apricots, cherries, 
plums, and peaches, .which were mixed when in a rot¬ 
ting condition with earth to make a more solid mass. 
He succeeded in rearing them in bread soaked in milk 
and boiled egg and kept at a temperature of 25 0 C., 
but he was unable to rear them to maturity in cheese. 
The preference which the typhoid fly has for horse 
manure as a breeding nidus has been clearly shown 
by a multitude of observations. One of the early ex¬ 
periences of the writer consisted in an effort to keep 
the stables of the U. S. Department of Agriculture at 
Washington in a strictly sanitary condition. The ma¬ 
nure was swept up and placed each day in a screened 
closet. As a result there was a notable diminution of 
flies in all of the buildings for hundreds of yards 
around for several weeks; whereas up to the time when 
the experiment began they had been a nuisance through¬ 
out that portion of the city. One of the many letters 
received which bear upon this point may be quoted: 
Washington, D. C, February 10, 1908. 
“Dr. L. O. Howard, 
Department of Agriculture, 
Washington, D. C. 
“Dear Dr. Howard : 
“For the greater part of the last two years I have oc¬ 
cupied a room on the third floor of the Faculty Club on 
the Campus of the University of California at Berkeley, 
Calif. During most of the time the number of flies in 
