FRANCIS, a celebrated natural historian, was the only son of Sir Francis Willughby, and was born in 1635. He was fond of study from his childhood, by which means he attained great skill in all branches of learning, and particularly in the mathematics. But to the history of animals, which was in a great measure neglected by his countrymen, he particularly applied himself; and for this purpose carefully read over what had been written on that subject by others. He prosecuted his studies in Trinity College, Cambridge, where he took the degree of A.B. in 1656, and of A.M. in 1659. In the following year we find him residing at Oxford for the benefit of the public library. He then travelled in search of natural knowledge, several times over his native country, and afterwards into France, Spain, Italy, Germany, and the Low Countries, attended by his ingenious friend John Ray. He was Wilming- humble, sober, honest, and pious. This learned gentle- man died on the 3d of July 1672, at the age of thirty-seven, having impaired his health by his application. He wrote, Ornithologiae libri tres, 1676, fol. It was afterwards trans- lated into English, with an appendix, by Ray. Historia Piscium libri quatuor, 1686, fol. Letters of Francis Willughby, Esq., added to Philosophical Letters between the learned Mr Ray and several of his correspondents, and published by Dr Derham. Several Ingenious Papers in the Philosophical Transactions. (See Ray.)