•20 
Blood Parasites 
granules arranged in a radial manner. The centrosome is usually round, 
sometimes oval or rod-shaped, and stains very deeply with Giemsa’s 
stain. Its position in the body varies according to the size, and 
therefore probably the age, of the parasite. In the smallest forms it 
lies near or actually in contact with the nucleus, whilst in the larger 
forms it is placed somewhat near the rounded end of the pear-shaped 
structure. It usually measures about 1 fx in diameter. 
A hagellum starts from, or more generally near, the centrosome and 
is in some cases thickened or V-shaped at first. It is usually about 
4 to 5 /u, in length, of which 3'5 fx is free. In a few there are two flagella, 
originating from or near a single centrosome, and these are distinctly 
separate in their course inside and outside the body. 
The average size of the immature trypanosome was 6'3/ir in length 
and 2'7/a in breadth, but larger forms measuring 7'5 fx by 4'5 were seen, 
containing two nuclei and two centrosomes placed side by side with 
two flagella to each centrosome. (Plate II, fig. 9.) 
One circular body measuring about 5 /r in diameter was found in 
which there were eight nuclei arranged in a ring lying towards the 
margin of the cell. This showed no evidence of flagella, and as 
unfortunately all these preparations were mounted in so-called neutral 
Canada balsam they have faded too much to say whether there was any 
indication of a centrosome, but camera lucida drawings made at that 
date show no such signs. 
Adult Trypanosomes. These somewhat resembled T. leiuisi but 
were very much smaller, possessed a relatively long flagellum, and were 
generally very much curled up, so that the posterior end came in 
contact with the anterior end, and they resemble to some extent the 
letter Q. (Plate II, fig. 8.) 
During life they are very active, coiling and uncoiling, but do not 
make much progress. The nucleus is situated somewhat nearer the 
anterior than the posterior or aflagellar end; it shows a radiate 
structure. The centrosome is generally round and is placed very near 
the posterior exti’emity, but it is not actually at the tip, as the extreme 
posterior end terminates in a very fine sharp point which is 1 to 1*5 /x 
from the middle of the centrosome. The latter is relatively large, and in 
some cases seems to project beyond the margin of the body proper. 
From or near the centrosome the border of the undulating membrane 
starts, and runs with few turns to the anterior extremity, becoming free 
as a somewhat long Hagellum which is about two-thii’ds the length of 
the body. 
