100 NEW YORK ZOOLOGICAL -SOCIETX 
oyster was normal in every respect, and its heart was pulsating 
when opened. In oyster No. 2, 25 per cent. of the organisms iso- 
lated from it were found to be Bacillus typhosus. On opening 
this oyster no signs of life could be detected. No. 3 was dead be- 
yond doubt, and had turned black; and in this case all organisms 
tested were found to be B. typhosus. 
The two little-neck clams examined looked normal in every 
way, except that no pulsation could be noticed in clam No. 2. No 
typhoid bacilli could be found in No. 1, whereas No. 2 showed all 
organisms to be B. typhosus. 
It was seen from this that this method of infecting the tanks 
could not be used, so in all further work the tanks were infected 
in the following manner: 
The bacilli were sown on agar planted in flasks. They were 
incubated for 24 hours. At the end of 24 hours about 20 c.c. of 
sterile sodium chloride solution was placed in the flask, and the 
growth washed off the agar into this solution. This was poured 
into the tank, and more fresh sodium chloride solution placed in 
the flask, to wash the remaining bacilli off, as the whole growth 
could not be removed at the first washing. This was also added 
to the tank. 
After this the oysters were removed at the end of certain pe- 
riods for examination. After the first experiment five oysters 
were removed each time. These were washed and scrubbed to re- 
move as many organisms as possible from the shell. The oyster 
was then opened by cracking off the edge and inserting a sterile 
platinum needle and stirring it around, then draining the juice 
into a sterile beaker glass. One-tenth of a c.c. of this juice was 
used to inoculate each tube of plate media. The plates were in- 
cubated for 48 hours, and then either 20 or 40 colonies were 
planted in bouillon—that is, 20 or 40 colonies from each oyster of 
the 5 removed, making either 100 or 200 colonies examined. At 
the end of 24 hours the bouillon cultures were tested in the hang- 
ing drop, with the serum of a young goat immunized to B. typho- 
sus, and having great agglutinative power for this organism. The 
dilution used was 1-800. If the organisms in the tube did not 
agglutinate, they were thrown out, and no further test was made 
on them. If they showed agglutination, they were planted in 
Dunham’s solution, and tested for indol, also in lactos bouillon 
for gas production, and in milk for coagulation; but later in my 
work I relied wholly on the agglutination test. | 
It will be seen from Chart I, that when the oysters remain in 
the infected water the B. typhosus may remain present until the 
