238 THE HOUSE FLY—DISEASE CARRIER 
ible numbers under buildings, between the earth and 
the floor. 
Dr. J. A. Lintner, in his Ninth Report of the State 
Entomologist of New York (Albany, 1893), gave a 
number of instances of like occurrences of this fly in 
houses, both in spring and in winter, in various parts of 
New York State. A good description was given by a 
correspondent of the Washington Bureau of Entomol¬ 
ogy, living in Lasalle County, Illinois. The corre¬ 
spondent stated that the cluster fly had been a pest in 
her household for fifteen years. She wrote, “They 
seem to prefer to occupy the rooms on the north side 
of the house and those that are used but little. They 
gather in large bunches in the corners and along the 
edge of the ceiling of the room. They cannot be driven 
out as other flies, but must be killed outright to get 
rid of them, and when you mash them the odor is like 
that of honey. We have tried nearly everything that 
we heard of that was recommended to us, with no ef¬ 
fect. It seems impossible to get rid of them or to keep 
them out of the house, for they crawl in through the 
smallest places in the windows.” 
Other correspondents have reported the odor of the 
crushed bodies as being very disagreeable. 
Incredible as it must seem, practically nothing is 
known about the early stages of this abundant and trou¬ 
blesome fly. European writers either admit that they 
know nothing about it or give rather vague statements. 
Robineau Desvoidy, speaking of the genus Pollenia as 
a whole, states that their eggs are laid in decomposing 
