T. gondii stages visualized by light microscopy. A. Extracellular tachyzoites from the peritoneum of a mouse seven days post infection, stained with H&E. (63x) B. Replicating parasites inside a monocyte, stained with H&E. (63x) C. Bradyzoites found in the brain of a chronically infected mouse, stained with H&E. (40x) D. Unstained cyst from brain homogenate (40x).