Modern texts continue to cite Broca's 1861 study of a single patient, Tan, as the first definitive localization of a cerebral function, specifically, articulate speech. We describe the development of Broca's theory from his initial support in 1861 for Bouillaud's view that speech is localized in both frontal lobes to his description in 1865 of a center for articulate speech in the third left frontal convolution. We have translated Broca's 1865 French report. Despite the revival of "classical" anatomically based concepts of discrete aphasic syndromes, numerous clinicoanatomical correlation studies have failed to confirm the specific language impairment described by Broca. Broca's own descriptions of language development in the third right frontal convolution following left hemisphere damage also raise questions about the validity of theories of brain-behavior relationships based on punctate localization of specific mental functions.