This is the first English-language publication of the complete works of the great Spanish neurohistologist, Santiago Ramon y Cajal, on the cerebral cortex. The new translations include all Cajal's very early contributions on the cortex of small mammals, relevant chapters from his definitive textbook, and all his great works on the human cerebral cortex made at the peak of his career. The book also presents Cajal's surveys of cortical structure, which date from his later years. The book is extensively annotated, and the authors have verified and completed all Cajal's references. Special introductory chapters review the state of knowledge during each period covered, and the work concludes with an extensive essay on modern cortical neurohistology in which the quality and lasting significance of Cajal's contributions are highlighted.