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 Rh is no more invariable than other characters, and even more uncertain than such as are founded on insertion, or the connexion of one part with another. Against these inconveniences the author of this System has provided an all-sufficient remedy. At the head of every Class and Order, after the genera which properly belong to them, he enumerates, in italics, all the anomalous species of genera stationed in other places, that, by their own peculiar number of Stamens or Styles, should belong to the Class or Order in question, but which are thus easily found with their brethren by means of the index.

It is further to be observed that Linnæus, ever aware of the importance of keeping the natural affinities of plants in view, has in each of his artificial Orders, and sections of those Orders, arranged the genera according to those affinities; while at the head of each Class, in his Systema Vegetabilium, he places the same genera according to their technical characters; thus combining, as far as art can keep pace with nature, the merits of a natural and an artificial system. His editors have seldom been aware of this; and Murray