Since in the following experiments,
with Salmonella enteritidis as the test
organism, it was desirable to reduce
surface contamination of the flies to a
minimum, two methods of feeding were
used. In the first of these a small
cylindrical glass cup was filled to within
2 to 2.5 mm. of the top with infected
food (10 ml. of an 18 hour broth culture
of Salmonella enteritidis in equal
parts of milk and water).
Over this
was placed a fine mesh screen. It was
intended in this manner to prevent the
flies from standing on or falling into the
liquid food.