36 5 
being sometimes as many as five to a field, but, as a rule, they were 
scanty. A few posterior nuclear forms were found on the 
thirtv-second day, at a time when the total number of parasites in 
the blood was about five to a field. The animal rapidly lost weight. 
Before infection it weighed 650 lbs., five days before death 548 lbs. 
The temperature remained constant, between 103° and 103 8° F., 
until a few hours before death, when it fell to 99 0 F. On the 
twenty-fourth day after inoculation the animal appeared ill for the 
first time. A few days later distinct swelling of the skin, 
subcutaneous tissues below the eyes and over the nasal bones was 
noticed. This condition was accompanied by some slight loss of 
hair and persisted until death. On the thirty-fifth day the animal 
was very ill. It had lost nearly 100 lbs. in weight, could hardly 
stand and refused food. The cornea of the left eye was hazy, and 
the conjunctiva slightly injected. The next day the animal was 
down and could not get up. Death occurred on the thirty-eighth 
day. At the time of death parasites were present in the blood in 
fair numbers (4-5 to a field). 
Mice. 
Rhodesian strain. Twenty experiments. 1 he disease ran an 
acute course. The animals were inoculated intraperitoneally with 
5 c.c. of blood containing approximately 5 00 trypanosomes to a 
cubic millimetre. Parasites were usually present in fair numbers, 
and the posterior nuclear forms frequently found. Incubation 
period, two to five days; average three days. Duration, three to 
twenty days; average eleven days. 
Rats. 
Rhodesian strain. Forty-five experiments. The strain has been 
preserved by passage through these animals. In each case the rats 
were inoculated intraperitoneally with 1 c.c. of infective blood well 
diluted with citrated saline solution—a cover-slip preparation of 
which showed, as a rule, one to five trypanosomes to a field. The 
disease was fairly acute, and parasites were often present in the 
blood in considerable numbers. Posterior nuclear forms were 
usually found when the blood contained numerous parasites. Very 
