2t 
were present. At the twenty-fourtli hour after injection a count 
gave red, 5,050,000 ; white, 46,000. The blood was negative. The 
leucocytes remained high for a couple of days and then fell; in none 
of the phagocytes could any remains of trypanosomes be found. 
Treatment: ro c.c. of ten per cent, solution was given twice a week. 
The animal increased in weight. The auto-agglutination of the 
corpuscles began to be less accentuated, and the number of erythro¬ 
cytes and the haemoglobin rose. The local oedema disappeared. 
On the thirty-ninth day dysentery appeared, and the animal 
succumbed on the forty-eighth day after injection. The autopsy 
showed a very severe haemorrhagic and necrotic enteritis, with 
slightly enlarged spleen. Kidneys normal. Glands, small; inguinal 
group haemorrhagic. The blood was non-infective in amounts of 
ro C.C., but infective if 15 c.c. of pure blood was used. Unfortunately, 
the arsenic was discontinued on the appearance of dysentery. A 
second monkey, inoculated from the first Rhesus just before treat¬ 
ment was begun, was treated with the same doses of arsenic; the 
parasites disappeared in the same way, but the animal quickly 
succumbed to dysentery. 
' Many rabbits inoculated with this strain have been treated. It 
was found that unless treatment was started early that the majority 
of animals died as it was so exceedingly virulent. With these animals 
treatment was begun earlier and higher doses given than with the 
standard " Gunjur” strain. Despite treating the animals early, some 
died. With this strain treatment had to be kept up longer. Some 
rabbits have survived eight months after injection, while all the 
controls have died in fourteen to thirty-six days. Guinea pigs 
infected with this strain do not react so well to the treatment. Rats 
must be treated early and with high doses if treatment is to be 
successful Mice infected with this strain react if treatment is 
commenced early enough. The action of atoxyl on the various 
trypanosomes has been studied, and after numerous observations, 
continued for the whole period during which the drug was adminis¬ 
tered, the effect appears to be as follows: - 
■ On administration of arsenic compounds into an animal showing 
numerous parasites in the blood the following action on the trypano¬ 
somes will be noticed. For the first three-and-a-half to four hours, 
depending on the dose used, very little change in the parasites can 
