It might appear that the merit of Antoine de Jussieu is rated too low, when we praise him chiefly and simply for providing the families with characters; but this praise will not seem small to those who know the difficulty of such a task; very careful and long-continued researches were necessary to discover what marks are the common property of a natural group. Jussieu’s numerous monographs show with what earnestness he addressed himself to the task; and it must be added, that he was not content simply to adopt the families established by Linnaeus and by his uncle and the limits which they had assigned to them, but that he corrected their boundaries and in so doing established many new families, and was the first who attempted to distribute these into larger groups, which he named classes. But in this he was not successful. His attempt to exhibit the whole vegetable kingdom in all its main divisions, to unite the classes themselves into higher groups, was also unsuccessful, for these larger divisions remained evidently artificial. The three largest groups on the contrary, into which he first divides the world of plants, the Acotyledons, Monocotyledons, and Dicotyledons are natural; but they had been already partly marked out by Ray, afterwards by Linnaeus, and finally in Bernard de Jussieu’s enumerations. Still it is the younger Jussieu’s great and abiding merit, to have first attempted to substitute a real division of the whole vegetable kingdom into larger and gradually subordinate groups for mere enumerations of smaller co-ordinated groups,—an undertaking which Linnaeus expressly declared to be beyond his powers. If then Jussieu’s system was far from giving a satisfactory insight into the affinities of the great divisions of the vegetable kingdom, yet it opened out many important points of view, from which they could afterwards be discovered, and it certainly became the foundation for all further advance in the natural method of classification; for this reason it is necessary to give a view of it in the following table:— A. L. de Jussieu’s System of 1789.