Series I. deals with "Reports of Field Experiments, Experiments on Vegetation, &c., published 1847-1900 inclusive," and contains 101 papers. These reports on plants are concerned chiefly with the results obtained by growing some of the most important crops of rotation separately, year after year, for many years in succession, on the same land without manure, with farm-yard manure, and with various chemical manures, the same description of manure being, as a rule, applied year after year on the same plot. Amongst the numerous field experiments conducted on these lines one of the most interesting is the field known as Broadbalk field, in which wheat has been grown continuously for over 60 years. The results show that wheat can be grown for many years in succession on ordinary arable land if suitable manure be provided and the land be kept clean. Even without manure of any kind the average produce for 46 years--1852 to 1897--was nearly 13 bushels per acre, about the average yield per acre of the wheat lands of the world. On this field it was found that mineral manures alone gave very little increase, whilst nitrogenous manures alone gave a much greater increase than mineral manures alone, but the mixture of the two gave much more than either alone. It is estimated that the reduction in yield, due to exhaustion, of the unmanured plot over 40 years--1852 to 1891--was, provided it had been uniform throughout, equivalent to a decline of one-sixth of a bushel per acre. It is related that a visitor from America, when being shown over the Broadbalk field, said to Sir John Lawes, "Americans have learnt more from this field than from any other agricultural experiment in the world." Another set of field experiments of exceptional interest is that relating to the "Mixed Herbage of Permanent Grass Land." The land was divided into twenty plots. Two plots have received no manure from the commencement of the experiment, two have received a dressing of farm-yard manure each year, whilst the remainder have each received a different kind of artificial or chemical manure, the same kind being applied year after year on the same plot, except in a few special cases. Repeated analyses have shown how greatly both the botanical constitution and the chemical composition of the mixed herbage varied according to the kind of manure applied.