4 o 
film lias been under examination for some time. The 
processes occasionally break off and float about. 
Shorter and more granular processes emitted by the 
red cell are even commoner (Fig. u). 
Distinction of Species in Fresh Films 
Malignant Tertian.—The young rings are the 
smallest seen. The red cells in which they occur have 
sometimes, especially perhaps in severe infections, a 
slightly crenated appearance and peculiar dark colour 
(globuli rossi ottonati, old-brass coloured red cells). 
Pigment is rare. 
Simple Tertian. —I. The red cell is enlarged and 
pale. 2. The young rings are more flimsy (but are 
often extremely difficult to see), and the medium sizes 
may shew several pseudopodia. 3. Their motion is 
greater. 4. The pigment is very fine, reddish brown ; 
in the larger forms it is more easily recognizable. 
Quartan. —1. Red cell unchanged. 2. Motility 
slight. 3. Pigment compact and dark chocolate. 
Flagellation 
Select a case of malignant tertian* infection in 
which parasites have been found. On examining the 
patient about a week later, crescents (gametes) will be 
found in the blood. In about twenty minutes, or in 
hot weather in England in five minutes or less, many 
of these will be seen to become spherical and to get 
free of the corpuscle in which they were situated. 
Two varieties may be distinguished—the male, in 
which the pigment is distributed over the whole of 
the parasite, and the female, in which the pigment is 
* Flagellation may of course be studied also in simple tertian and quartan. 
