In the spring of 1663 Ray started together with Willughby and two other pupils (Philip Skippon and Nathaniel Bacon) on a tour through Europe, from which he returned in March 1666, parting from Willughby at Montpellier, whence the latter continued his journey into Spain. He had previously in three different journeys (1658, 1661, 1662) travelled through the greater part of Great Britain, and selections from his private notes of these journeys were edited by George Scott in 1760, under the title of Mr Ray's Itineraries. Ray himself published an account of his foreign travel in 1673, entitled Observations topographical, moral, and physiological, made on a Journey through part of the Low Countries, Germany, Italy, and France. From this tour Ray and Willughby returned laden with collections, on which they meant to base complete systematic descriptions of the animal and vegetable kingdoms. Willughby undertook the former part, but, dying in 1672, left only an ornithology and ichthyology for Ray to edit; while Ray used the botanical collections for the groundwork of his Methodus plantarum nova (1682), and his great Historia generalis plantarum (3 vols., 1686, 1688, 1704). The plants gathered on his British tours had already been described in his Catalogus plantarum Angliae (1670), which formed the basis for later English floras.