Wray was ordained on December 23, 1660, possibly in part due to Trinity's requirement that fellows should take orders. However, he forfeited his fellowship in August 1662, as he felt unable to accept the terms of the Act of Uniformity. After this time, he began to travel, seeking natural philosophical observations, particularly related to botany.
In the early-1650s, Wray began work on a catalogue of the plants in the Cambridgeshire countryside. His Catalogus plantarum circa Cantabrigiam nascentium (1660) described 558 species of native plant. By 1658, Wray was exploring outside Cambridgeshire. He undertook several tours throughout England, and by August 1660 had travelled to Scotland. In April 1663 he set sail for the continent, along with Willughby, Philip Skippon and Nathaniel Bacon. They travelled through Flanders, the Netherlands, southern Germany, Italy, Sicily, Malta, Swizerland and France. Wray returned to England in April 1666. On 7 November, 1667, he was elected a fellow of the Royal Society. In 1670, Wray dropped the initial ‘W' of his name in order to facilitate the Latinizing of his name.
Ray's travels had created material for his collaboration with Willughby, including observations of insects, fish, birds, language, customs and antiquities. Study of this material would keep Ray occupied for much of the remainder of his life. His Catalogus plantarum Angliae was published in 1670 and Fasciculus stirpium Britannicarum in 1688. This is considered a thorough work with extensive medical and pharmacological notes along with the descriptions of plants. Ray attempted to make new classifications of plants, though his retention of a primary division between trees, shrubs and herbs restricted the validity of his findings.
Historia plantarum, published in three volumes in 1686, 1688 and 1704, is considered the peak of Ray's botanical career. Around 6,100 species of plant were described in the first two volumes, with a further 10,000 species in the supplementary third volume. Sadly, the volumes lacked illustrations, mainly due to worries about their cost.
Willughby died in 1672, leaving Ray both an annuity and the care of his two young sons. On June 5 1673, Ray married Margaret Oakeley. Following disagreements with Willughby's widow, Ray and his wife returned to Essex. In 1679, they moved to the family house at Dewlands, where they lived for the rest of their lives. Between 1684 and 1689, the couple had four daughters, all of whom would later assist their father in his studies.
In the 1670s and 1680s, Ray revised Willughby's notes for a natural history of fish. Historia piscium was published in 1686, with 187 plates commissioned and financed by the Royal Society. In the 1690s he produced works on quadrupeds, snakes, birds and fish, before an examination of insects which was left unfinished at his death. In his later years, Ray was regularly in great discomfort. He died at Dewlands on 17 January 1705.
Sources:
Mandelbrote, Scott, John Ray, Oxford Dictionary of National Biography
[http://www.oxforddnb.com/view/article/23203, accessed 18 Feb 2011]