Carl Linnaeus a rare book, if he let Linnaeus stay with him, and Burman accepted. On 24 September 1735, Linnaeus moved to Hartekamp to become personal physician to Clifford, and curator of Clifford's herbarium. He was paid 1,000 florins a year, with free board and lodging. Though the agreement was only for a winter of that year, Linnaeus practically stayed there until 1738. It was here that he wrote a book "Hortus Cliffortianus", in the preface of which he described his experience as "the happiest time of my life." (A portion of Hartekamp was declared as public garden in April 1956 by
Carl Linnaeus he sometimes recognised taxa of a lower (unnamed) rank; these have since acquired standardised names such as "variety" in botany and "subspecies" in zoology. Modern taxonomy includes a rank of family between order and genus and a rank of phylum between kingdom and class that were not present in Linnaeus' original system. Linnaeus' groupings were based upon shared physical characteristics, and not simply upon differences. Of his higher groupings, only those for animals are still in use, and the groupings themselves have been significantly changed since their conception, as have the principles behind them. Nevertheless, Linnaeus is credited with establishing