Galen (Claudius, Galenus) 130-200
Galen was born at Pergamun. He was carefully educated by his father who as the result of a dream chose him to enter the medical profession in which he became very celebrated. He studied at Pergamun, Smyrna, Corinth and Alexandria. He practiced in his native city and finally in Rome he became physician to the Emperor Marcus Aurelius.
He wrote a large number of works on medical and philosophical subjects. Eighty-three treatises attributed to him are still extant.
His anatomical investigations were unrivalled in antiguity for their fullness and accuracy. He was an indefatigable dissector and also may be regarded as the founder of experimental physiology. After Hippocrates he was the most distinguished physician of antiquity. He acknowledged his obligations to Hippocrates and Alexandrian anatomists. His physiological investigations were revolutionary. One of his greatest contributions was that arteries contain blood not air. He described valves of the heart, and probably knew about anastomosis of vessels. He partially grasped the principle of lesser circulation. Galen's best work is in connection with the brain, nerves and spinal cord. He understood the need of nerves in causing muscles to move.
Galen's work marked the close of the ancient period and no botanical investigator of note is known until Albertus Magnus.