RUYSCH (Frederic), son of Henry Ruysch commissary of the States-general, was born in 1638, and proved one of the greatest anatomists that ever appeared in Holland. He studied at Leyden and at Franeker, where he took his degree as doctor of physic, and settled at the Hague. A piece which he published in 1665, De vasis lymphaticis & lacteis, procured him an invitation to be professor of anatomy at Amsterdam; which he gladly accepted, and where he was continually employed in dissections, to examine every part of the human body with the most scrupulous exactness. He died in 1731, after having writ several books, in which he published many discoveries, yet not so many as he himself from his confined reading imagined.