26 Col. Sir D. Bruce and others. Zrypanosome [July 22, 
inoculated with a drop of blood from the heart of an ox, Experiment 450, 
dead of Trypanosoma vivax disease, is as follows :— 
March 3, 1909.—-Inoculated six tubes. The trypanosomes are very scarce in the blood. 
March 6.—Tube No. 1 has been examined daily for signs of growth. Nothing living 
has been seen. The tube remains sterile. 
March 8.—To-day many very active trypanosomes are seen. ‘They are single or in 
small groups of ten or twenty or so. The cell-contents are granular. The cells possess 
flagella, but no obvious undulating membranes. There are’ many dividing forms to be 
seen, and division is evidently going on rapidly, as many individual trypanosomes appear 
to be undergoing fission into three or more at the same time. 
March 9.—Since yesterday an immense multiplication has taken place. The trypano- 
somes are still very active. They appear to have free flagella and long-pointed, finely 
granular posterior extremities. 
March 11.—Many highly active trypanosomes seen. They are elongated, thin, and 
have a long free flagellum, sometimes as long as the body itself. 
The trypanosomes remained alive and active up to 20 or 30 days, when the 
tubes became contaminated, or dried up, and were thrown away. 
Size—Cultural forms of Z'rypanosoma vivax vary much in size. At first, 
when they begin to multiply, on or about the sixth day, the individuals 
forming groups are about 15 microns in length. Next day they are longer and 
thinner, and later many are seen 50, 60, or more, microns in length. | 
Shape.—At first, the young forms are oval or elliptical in shape; after- 
wards they become more attenuated; and later still may be seen as huge 
trypanosomes with undulating membranes and long free flagella. 
Contents of Cell_—In the living unstained condition this appears to be 
finely granular. 
Undulating Menbrane—In the smaller forms composing the groups no, 
obvious undulating membrane can be made out. 
Flageilum.—This is free and well developed. 
Motion.—The single forms are extremely active. 
B. Fixed and Stained (Plate 5). 
Protoplasm.—tIs homogeneous, but contains many irregular granules and 
vacuoles. | 
Nucleus.—Is usually broken up and diffuse. 
Micronuclews.—Often difficult to distinguish. Sometimes placed anterior, at 
the side of, or posterior to, the nucleus. 
Flagellum.—Well developed free flagellum. 
Undulating Membrane.— Present in the older free forms. 
