of plants do we find analogous groups? I am unable satisfactorily to answer the question, but still I cannot help thinking as I shall by and by show that pa- rallel circles or groups may yet be found, and probably, when once traced will prove as self evident, even to the most casual observer, as the animal ones now are. The same remark is applicable to the Annulosæ and Exogens, where the parallel circles have not, so far as I am aware, been traced in the two kingdoms, but probably may readily be so, when the attempt is made by a competent ob- server who has made himself acquainted with the Zoological system, which, in first principles at least, seems to have gone far ahead of the Botanical.
Dr. Lindley in his elements of Botany has presented us with sketches of two circular arrangements of plants; each perhaps superior to those of any of his cotemporaries, but in which, so far as my comparatively limited acquaintance with the subject of circular arrangements, and indeed with the relationships of the vegetable kingdom generally, enables me to follow him, he does not appear to have succeeded in bringing out the affinities and analogies of his vegetable circles so clearly as Zoologists have their animal ones. In this opinion I may perhaps be greatly in error and in venturing to express it may only be exposing my own ignorance of the subject, but still, such is the impression conveyed to my mind by their examination. The first series of analogies between the two kingdoms is however known, and when Botanists have succeeded in tracing the second it seems probable the subsequent ones will prove less difficult, as the mass of knowledge of vegetable structure and function already acquired, but hitherto only sparing- ly applied to such purposes, will supply many new elements well adapted for forwarding the work of systematic arrangement. Jussieu founded his secondary divisions, in the Exogens, on the absence or presence of petals and on their be- ing one or more: hence his apetalous monopetalous and polypetalous groups: and his terteary ones on the relative position of the ovary to the flower, that is, whether the stamens have an inferior (hypogynous) superior (epigynous) or middle (perigynous) attachment. DeCandolle has adopted this method with con- siderable modifications, but I do not think improvements as a natural arrange- ment, though well calculated to facilitate its use in practice.
Professors Lindley and Endlicher have each constructed arrangements of the natural orders, or Natural Systems of Botany, both very different from each other and from their apparently more simple, though less natural predecessors. This improvement they seem to have accomplished by the avoidance of what may be called linear characters, which must inevitably, in some part of their course, become constrained and artificial; causing, like the Adjutant's measur- ing rod, the widest separation of brothers, simply because the one happens to be the tallest the other the shortest man in. his Regiment. By allowing greater scope or circularity to their divisional characters, they have been enabled to
