60 
GENERAL PRECAUTIONS, 
It will be unnecessary to enter into a detailed description of the 
laboratory and apparatus used, for both were such as are always re- 
quired for preliminary bacteriological studies. In general it can be 
stated that all the customary cleanliness and precautions Avere success- 
fully observed. The apparatus was thoroughly cleansed after using, 
and either disinfected or sterilized. Glassware requiring it was placed 
in sulphuric acid for a time, subsequently washed, rinsed in alcohol, 
and sterilized. Test tubes in which cultures had been made were first 
filled with water, again plugged, and boiled for a couple of hours, kill- 
ing the germs and lessening the danger of accidental infection from es- 
caping spores. After boiling, the tubes were washed quite clean in 
water and placed in sulphuric acid over night. The following day they 
were washed, rinsed in alcohol, and sterilized. When making trans- 
fers of cultures from old to fresh media, the needles were always first 
dipped in acid and sterilized, then in distilled water, and again ster- 
ilized. To some these may seem to be extreme precautions, but the fact 
that the sterilizing, filtering, and culture inoculating was all done in 
the same small room, fully justifies them. That cleanliness and 
thorough disinfections were constantly practiced, may be concluded 
from the fact that at no time were any stock media lost through acci- 
dental infection or faulty sterilization. At no time was a culture lost 
through accidental contamination. 
The incubator was provided with a thermostat, and the temperature 
controlled at will for any given purpose or set of conditions. 
The infection experiments were carried on in another portion of the 
city. Two large rooms were fitted up, thoroughly cleaned and fumi- 
gated. In one the experiments with the particular microbe under study 
would be carried on, in the other the check experiments. Six-inch 
flower pots, covered with netting, were used as cages. These were 
thoroughly washed with a disinfectant before being employed in any 
experiment. For each experiment a different pot was used, to avoid 
the danger of mixing the germs. After each experiment, the room 
was thoroughly fumigated before another was begun. 
CULTURE MEDIA. 
Many media could be profitably experimented with in the study of 
reducing the problem of insect diseases to a practical basis. When, 
however, immediate practical results are wrongly considered the pri- 
mary objects and experimentation is inaugurated upon that basis, it 
becomes impossible to use, at first, more than a few of the standard 
media. Those used in this work were beef broth, broth agar- agar, 
broth gelatine, and potato. The two most extensively used were beef 
broth and broth agar-agar, and for the purposes of this report it will 
