1908.] New Variety of Trypanosomiasis. 549 
to March 8. The former animal died at sea during a heavy gale, while the 
other was sent to the Brown Institute after my arrival in London on April 6. 
Rabbits —One was injected intraperitoneally with 2 cc. of the blood of the 
ox on March 2 while the other was injected, at the same time, with 
2 c.c. of the same blood, subcutaneously. 
The subcutaneously injected rabbit was despatched from the port of 
Marseilles to M. Mesnil, at the Pasteur Institute in Paris, and I have had 
the pleasure of several reports from him on the matter. It would seem 
that no trypanosomes have ever appeared in that animal, which remains still 
in good health. The intraperitoneally injected animal was taken by me to 
the Brown Institute and there I found several trypanosomes in the blood. 
They were, however, extremely few and appeared very sluggish as compared 
with those seen in the horses and the ox. 
fiats—Two large grey rats were fed with infected horse blood on 
February 14 but never seemed to have become infected. 
Description of the Trypanosome. 
Its length as seen in the blood of the horses appeared to be from 13 p to 
16», the mean being 15y. The breadth measured from 0°75 uw to 1:25 p, 
the mean being 1. The blunt end is sometimes rounded but in many it 
tapers to a sharp point. 
The nucleus is placed about 4yufrom the blunt end and measures from 
2 to 3p in length, being most usually about 2. The breadth 
approximates to 1 «4 but extremes may be found from 0°75 uw to 1:25 p. 
The thickness of the parasite is usually greatest between the centrosome 
and the nucleus. The centrosome, which rarely showed evidence of division, 
is placed close to the blunt extremity; sometimes a space about 1 yw in 
extent intervenes between it and the actual extremity. 
In size, this trypanosome somewhat resembles the 7. dimorphon, but is 
smaller and rather more delicate. M.Mesnil, who has kindly given me his 
opinion on the parasite, confirms me in this view, and states that he also 
considers it as being different from the 7’. congolense, which latter M. Laveran 
considers as distinct from the 7’. dimorphon. 
On my arrival in London, the infected guinea-pig, rabbit, and monkey 
were placed under the charge of Professor Rose Bradford, who kindly 
arranged to have further investigation made of this interesting parasite. 
I take this opportunity of expressing my thanks to him for his kind 
assistance. 
