The scientific studies of Mary Kingsley (1862-1900) added much to European knowledge of African wildlife. She brought back one previously unknown species of fish, six new subspecies that had not been named, a previously unknown snake, and eight new insects. It was a great achievement for someone with no scientific training.

Mary Henrietta Kingsley was born in London on October 13, 1862, four days after her parents' wedding. Her father, a wealthy physician, and her mother, his cook, had an uneasy marriage. Her mother did not fit into her father's social world, and retreated to her bedroom, claiming ill health, for the rest of her life. Kingsley's father, George, was a personal physician to various aristocrats, traveled extensively--for months and sometimes for years--and was seldom at home.

The family lived in an unusual house, in which all the front windows had been bricked in. Inside the house, darkness reigned because...