English: Fig. 1.—Trypanosoma gambiense in the blood from a case of sleeping sickness in a European. The ilmlulatory membrane is clearly seen; the head of the organism with its micro nucleus is in Contact with a red blood corpuscle. Magnification 2000 diameters.

Fig. 2.—A. and B. The spirochaete pallidum. A shows the organisms seen in a section of mucous tubercle stained by Levaditi’s silver method; the lowest with 8 equal spirals and a pointed end is the most typical. Magnification 1200. B. Spirochetes in a smear preparation stained by Leishman. Magnification 2260.

Fig. 3.—Section of the brain of a European who died of sleeping sickness, showing an enormous increase of large branching neuroglia cells around a small vessel of the cortex. Magnification 450.

Fig. 4.—Very marked syphilitic arteritis, showing great diminution of the lumen, mainly caused by an inflammatory thickening of the inner coat. Magnification 5.

Fig. 5.—Section of the base of the brain of a monkey that died of experimental sleeping sickness caused by inoculation of the Trypanosoma gambiense. Magnification 250.

Fig. 6.—Longitudinal section of a perivascular sheath of the cortex of a monkey that died of experimental sleeping sickness. The lar e branching neuroglia cells are seen undergoing pro life ration. Magnification 600.

Fig. 7.—Longitudinal section of a small vessel of the cortex from a case of well-marked general paralysis of the insane. Magnification 250.

Fig. 8.—Transverse section of a small vessel of the cortex from a case of sleeping sickness, showing the perivascular cell infiltration of lymphocytes and plasma cells. Magnification 250.

Fig. 9.—Transverse section of a small vessel of the cerebral cortex from a case of syphilitic gummatous meningitis, showing the same perivascular cell infiltration of lymphocytes and plasma cells as seen in figs. 7 and 8. Magnification 250.