Page:Aspects of nature in different lands and different climates; with scientific elucidations (IA b29329668 0002).pdf/218

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with "foliis simplicibus," and the rest with pinnate leaves. The genus Aralia shews still greater independence in the form of the leaves: "folia simplicia, integra, vel lobata, digitata et pinnata." (Compare Kunth, Synopsis Plantarum quas in itinere collegerunt, Al. de Humboldt et Am. Bonpland, T. iii, p. 87 and 360.)

Pinnated leaves appear to me to belong chiefly to families which are in the highest grade of organic devolopment, namely, the Polypetalæ; and among these, in the Perigynic class, to the Leguminosæ, Rosaceæ, Terebinthaceæ, and Juglandeæ; and in the Hypogynic, to the Aurantiaceæ, Cedrelaceæ, and Sapindaceæ. The beautiful doubly-pinnated leaves which form one of the principal ornaments of the torrid zone, are most frequent among the Leguminosæ, in Mimoseæ, also in some Cæsalpinieæ, Coulterias, and Gleditschias; never, as Kunth remarks, in Papilionaceæ. "Folia pinnata" and "folia composita" are never found in Gentianeæ, Rubiaceæ, and Myrtaceæ. In the morphological development presented by the abundance and variety of form in the appendicular organs of Dicotyledones, we can at present discern only a small number of general laws.