Abstract
The circulation changes in canaries infected with Plasmodium cathemenum were studied by use of a quartz rod micro-illuminator at 96 X magnification. As the parasitic count rose, white cells stuck to the endothelium of the venules, followed by plasma leakage, then sticky clumps of red cells formed, transient thromboses occurred and the blood became progressively more sluggish. Larger numbers of thromboses occurred and death soon followed.