Portrait of Santiago Ramón y Cajal.

Source: U.S National Library of Medicine, History of Medicine Division Photographer unknown Kindly provided by U.S National Library of Medicine

Santiago Ramón y Cajal

Photo: Legado Cajal. Instituto Cajal (CSIC). Madrid.

Santiago Ramón y Cajal at work, ca 1915.

Photo: Legado Cajal. Instituto Cajal (CSIC). Madrid.

Santiago Ramón y Cajal in his laboratory in Madrid, surrounded by some of his students, ca 1915.

Photo: Legado Cajal. Instituto Cajal (CSIC). Madrid.

Santiago Ramón y Cajal at his desk, ca 1890.

Photo: Legado Cajal. Instituto Cajal (CSIC). Madrid.

Self-portrait of Santiago Ramón y Cajal in his laboratory in Valencia, ca 1885.

Photo: Legado Cajal. Instituto Cajal (CSIC). Madrid.

Pyramidal cells of the cerebral cortex of a cat.

Source: U.S National Library of Medicine, History of Medicine Division Photographer unknown Kindly provided by U.S National Library of Medicine

A schematic illustration of a section of the spinal cord depicting the nerve roots. Illustration by Cajal from the book Recuerdos de mi vida.

Source: U.S National Library of Medicine, History of Medicine Division Photographer unknown Kindly provided by U.S National Library of Medicine

Neuroglial cells of a cat. Illustration by Cajal from the book Recuerdos de mi vida.

Source: U.S National Library of Medicine, History of Medicine Division Photographer unknown Kindly provided by U.S National Library of Medicine

Detail of neural connections. Illustration by Cajal from the book Recuerdos de mi vida.

Source: U.S National Library of Medicine, History of Medicine Division Photographer unknown Kindly provided by U.S National Library of Medicine

Various types of nerve structures. Illustration by Santiago Ramón y Cajal from the book Die Retina der Wirbelthiere, Tafel II.

Source: U.S National Library of Medicine, History of Medicine Division Photographer unknown Kindly provided by U.S National Library of Medicine