That the French botanist had acquainted himself with the principles of Ray’s classification is unquestionable; in fact, Jussieu possessed the happy art of adapting the labors of others to perfecting his own conceptions. He made use of the simple language and accurate descriptions of Linnæus, divested of his pedantry. Ray had demonstrated that rigorous definitions in natural history are impossible, and, accepting the decision, Jussieu does not attempt to found his family orders or genera on any single character belonging to objects so various in their habits and organization as plants. During the last forty or fifty years other botanists have attempted various systems of classification. In those of De Candolle, Endlicher, Lindley, and of Brongniart, the distribution of plants into groups is founded, as in those of Ray and Jussieu, on the consideration of the cotyledons; of the polypetalous, monopetalous, and apetalous flowers; finally, upon the mode of insertion of the stamens. Names have changed; things remain the same; and if in their details the series of families or orders present certain differences, it only arises from the fact that a linear series is incompatible with the natural system, and that the connection of the intermediate groups may be expressed in various ways without affecting the general principles of the system. “The formation of natural orders by Jussieu,” says Ad. Brongniart, “is even now a model which directs botanists in their studies to the affinity which connects the various forms of vegetation. Many of these orders have doubtless been subjected to important modifications, both in extending and limiting them; the numbers have been more than doubled; but the number of species now known is increased more than sixfold. Since the publication of the _Genera Plantarum_, many points in the organization of plants which were either scarcely touched upon or were altogether unsuspected, have now been considered, and it is found that they do not destroy, but confirm, and perfect the work of Jussieu. One is even astonished to find that the numerous discoveries in the anatomy and organography of plants since the beginning of the century have not introduced greater modifications into the constitution of the natural groups admitted by the author of the _Genera Plantarum_. It is here that we recognize the sagacity of the savant who established them, and the soundness of the principle which guided him.” [Illustration: Flowers, Curious and Beautiful 1, Edelweiss; 2, Nigella Arvensis; 3, Parnassia; 4, Rhododendron; 5, Ophrys Arachnites; 6, Cypripedium Calceolus; 7, Nepenthes; 8, Gnaphalium Dioicum; 9, Ophrys Muscifera]