PLANT PARASITES INOCULATED INTO ANIMALS. _ 183 
IV. Twotrout. Each two shallow pricks in the throat outside near the junction of the gill arches. 
V. Two trout.. Each inoculated in the eye-socket. This time the skin was cut with a scalpel 
and a 2-mm. loop of the white bacterial slime was inserted. 
VI. Two trout. Each inoculated inside of the mouth at the base of the tongue by means of 
several needle-pricks. 
VII. Four roach. Each inoculated in the eye-socket. The skin was cut and a 2-mm. loop of 
the bacteria inserted. : 
VIII. Two roach. Each received several needle-pricks in the vicinity of the anus. 
IX. Fifty salmon trout fry (2 to 3 cm. long). They were put over night into 2 liters of water 
into which the remnant of the 4 agar cultures had been washed. The next morning they were trans- 
ferred to running water in the ordinary shallow hatchery boxes. 
Inoculations of April 4, 1908.—For these, 5 slant agar cultures 3 days old were used. 
The copious growth was washed off into 20 ce. of distilled water, making a milky suspension. 
All of the inoculations were made with the hypodermic syringe. 
X. Three leopard frogs. Each received icc. of the very cloudy fluid. This was injected into 
the muscles of the right thigh. 
XI. Three leopard frogs. Each received icc. under the skin on the abdomen. In one of these 
it was thought that the needle entered the abdominal cavity and for this reason it was kept separate, 
but the result was not different. 
XII. Two leopard frogs and 3 green frogs (Rana clamitans). Each received }cc. in the right 
eye-socket. 
XIII. Three brook trout. Each received }cc. in the eye-socket. 
XIV. Three brook trout. Each received jcc. of the very cloudy bacterial suspension. This 
was injected into the peritoneal cavity, the needle being set in just behind the ventral fins. 
XV. The virulence of the cultures was determined by making inoculations on four young daisy 
plants. These promptly contracted the disease. On June 1 these plants bore, where inoculated, 
tumors which were over an inch long by 0.50 to 0.75 inches broad and thick. 
Results: The results so far as tumor production is concerned were either negative or 
uncertain; all the fish have not been sectioned. The experiment was complicated by the 
discovery after the inoculations were begun that some of the fish were suffering from car- 
cinoma of the tongue, gills and thyroid region. Thenceforth, I examined each fish and 
inoculated only such as appeared to be sound, but nevertheless some of them may have 
then been about ready to develop such tumors as subsequently appeared. On March 25, 
1908, I caught and examined 50 of the 100 check fish and found 3 with carcinomatous throat 
tumors. Additional cases of this disease appeared in the checks, especially as the season 
advanced. Consequently the tumors which developed on the inoculated fish may have 
been due altogether to this disease, at least under the circumstances I could not be certain 
that they were not so caused. 
The frogs proved very resistant. None developed tumors. Most were finally chloro- 
formed at the end of the experiment. The few that died earlier gave no plain evidence of 
being in any way injured by the bacteria. 
Of the roaches one died the day after inoculation. The rest died in from 17 to 32 
days. None of the latter developed tumors. All were more or less inflamed, both roaches 
and trout. 
The inoculated trout (except the fry which showed no signs of disease attributable 
to the bacteria) died off faster than the checks in the main tank. They were, however, not 
under altogether the best conditions, 7.e., they were rather too crowded at the beginning 
of the experiment and the water was several degrees too warm toward the close of the experi- 
ment, but at the same temperature as that given to the check fish. If I were to do over 
this experiment in a climate like that of Washington, I would begin in the autumn, so as 
to allow the experiment to run for at least six months in cool weather. 
