The character of Sylvius was contemptible. He was a man of vast learning and at the same time was rough, coarse and brutal. His avarice led him to endure the cold winters of Paris without the benefit of a fire; in severe weather he would play at football, or engage in other violent exercise in his room, to save the cost of fuel. Once, and once only, did his friends find him hilarious; they wondered and asked the cause. Sylvius said he was happy because he had dismissed his “three beasts, his mule, his cat and his maid”. He was notoriously rigid in exacting his fees from students, and on one occasion he threatened to stop his lectures until two delinquents should pay their dues. Although he was supposed to have amassed great wealth, little of it was found after his death, and these sums were secreted in secluded places. In 1616, when his former residence in the _rue Saint-Jacques_ was demolished, numerous gold pieces were found. His reputation for miserliness followed him beyond the grave, as witness his epitaph: _Sylbius hic situs est, gratis qui nil dedit unquàm,_ _Mortuus et gratis quod legis ista dolet._ “Sylvius lies here, who never gave anything for nothing: Being dead, he even grieves that you read these lines for nothing.” In controversies he was violent and vindictive—a pastmaster in the use of bitter language. Jealous of the fame of other anatomists, he was particularly enraged when, in later years, he was opposed by Vesalius. Sylvius spoke of him not as Vesalius, but as _Vesanus_, a madman, who poisoned Europe by his impiety and clouded knowledge by his blunders. Such was the man who, in the mid-part of the sixteenth century, filled the position of highest honor in the Medical Faculty of the Collége de France[13]. Sylvius rendered valuable service in naming the muscles which, prior to his time, were designated by numbers. These, says Northcote[14] “were differently applied by almost every author; so that it was the description, and not the name, that must lead one to know what part was meant by such authors; and this required a previous thorough knowledge of anatomy”. He is the first writer who mentions colored injections and is supposed to have discovered this useful adjunct of anatomical study. He was the first anatomist who published satisfactory descriptions of the pterygoid and clinoid processes of the sphenoid bone, and of the os unguis. He gave a good account of the sphenoidal sinus in the adult but denied its existence in the child, as had been affirmed by Fallopius[15]. Sylvius also wrote intelligently concerning the vertebrae but incorrectly described the sternum. His observation concerning the valves in the veins gave rise to much discussion; the honor of priority in the discovery, however, belongs to other anatomists—Estienne and Cannanus. His discoveries in cerebral anatomy have caused his name to be attached to the _aqueduct_, the _fissure_ and the _artery of Sylvius_.