mately 100 flies were fed for 24 hours
on milk and water infected with Salmonella
enteritidis. At the end of the
24 hour period 10 flies were trapped
and anesthetized with ether. One wing
of each was clipped and the flies placed
in a sterile cage with approximately 100
uninfected, unmarked flies. The flies.
making up this population were fed
fresh uninfected milk and water daily.
Each day all dead flies and from 10
to 20 live unmarked flies were removed
and examined by washing for 10 minutes
in a mixture of 1 per cent sodium
hydroxide, 1 per cent aerozol and 5
per cent formaldehyde, followed by
washing from three to five times with
nutrient broth. The washed flies were
then ground in a sterile mortar and
the residue examined for the presence
10 unmarked flies from the second
group.