Science: Tsetse Fly

The blackest horror in darkest Africa is sleeping sickness. Very different from encephalitis lethargica, the sleeping sickness found in the U. S., this disease is caused by trypanosomes (parasitic protozoa) carried by the tsetse fly. Its toll is about 100,000 human victims a year and all the domestic animals the tsetse fly can find.

The earliest description of the disease was given by British Naval Surgeon John Atkins on his return from West Africa in 1734. He wrote: "The Sleepy Distemper (common among the Negroes) gives no other previous Notice, than a want of...