A comparison between the classification of the _Methodus Nova_ and that of the _Tables of Plants_ shows that whilst he left the Trees and the Shrubs almost unaltered, Ray remodelled his arrangement of the Herbs. Whereas, in the _Tables_, he had proceeded along three distinct lines of classification indicated by the characters of leaf, flower, and seed-vessel respectively, all regarded as equally important; in the _Methodus_, the leaf-character is subordinated to those of flower and fruit, and these are not kept distinct but are combined; a fundamental change of principle which is no doubt to be attributed to Morison's criticisms on the _Tables_. As Ray put it in his Preface: _Methodus haec differentias sumit a similitudine et convenientia partium praecipuarum, radicis puta, floris et ejus calicis, seminis ejusque conceptaculi_. The result is that many of the sub-divisions consist of groups of plants which are really natural, the precursors of several of the recognized Natural Orders of Phanerogams; such as Polygonaceae, Chenopodiaceae, Compositae, Umbelliferae, Rubiaceae, Boraginaceae, Labiatae, Cucurbitaceae, Scrophulariaceae, Cruciferae, Leguminosae, Gramineae. The principles adopted were capable of yielding even better results, had they been more rigorously applied and had the investigation of the plants been more minute. For instance, in genera xxi and xxii, with a little more attention to floral characters, the Ranunculaceous might have been separated from the Rosaceous genera, and all of them from the Malvaceae: similarly in genera xxvi-xxviii, the Scrophulariaceous, and possibly also the Campanulaceous genera, might have been segregated. One of the principal achievements is the recognition of the group Stellatae (Rubiaceae) as independent of, but related to, the Umbelliferae. For this, as well as other features, Ray was indebted to Cesalpino (conf. p. 11), as he acknowledges in his Preface. Nor does Ray fail to acknowledge his obligations to Joachim Jung, and to Morison whose _Preludia_ and _Historia_ he cites. But if Ray's _Methodus Nova_ owed something to Morison's _Historia_ (_Pars secunda_), at a later stage the _Historia_ (_Pars Tertia_) was even more indebted to the _Methodus Nova_. It is striking to observe how many of the groups constituted in the _Pars Tertia_ and in the _Sciagraphia_ (see p. 23) agree with those of Ray. It is this close association, amounting almost to mutual dependence, of the systems of these two botanists, that makes comparative criticism of them an impossibility. Their relative position may, in fact, be summed up in the statement that both of them adopted the principles of Cesalpino, and that Ray eventually proved to be more successful than Morison in their application.