It is very necessary to premise, that the plants observed and collected upon the North-west Coast, during the late voyages, are not to be considered as even a distant approach to an entire Flora of that extensive line of shore; since the long-established droughts of the seasons (as already remarked) in which the greater part of that coast was visited, had wholly destroyed plants of annual duration, with most of the Gramineae, and had indeed generally affected the mass of its herbaceous vegetation.  The collections, therefore, can simply be viewed as a gleaning, affording such general outlines of characteristic feature, as will enable the botanist to trace its affinity to the more minutely defined vegetation of the other equinoctial shores of the continent, as well as perceive its general, and, in some instances, almost total want of relation to the botany of other parts, in the more temperate or higher latitudes, where certain striking peculiarities of the Australian Flora more particularly exist.

Upon a general comparison of those collections that were thus formed on the North-west Coast, with the plants of the North and East Coasts, aided also by some few observations made during the voyages, it appears that (with the exception of Gompholobium, Boronia, Kennedia, and one or two unpublished species not referred to any family) the genera (of which several are proper to India) are the same, although the species are very distinct upon the several coasts.

Notwithstanding an identity of genera has been remarked upon their opposite shores, there are, nevertheless, certain others, frequent upon the East Coast, that appear wholly wanting on the north-western shores:  of these, the existence of some, even in the tropical parts of New South Wales, seems governed by the primary formation of the coast, its mountainous structure, and consequent permanency of moisture in a greater or less degree; namely, almost all the genera of Filices, the parasitical Orchideae, Piper, Dracontium and Calladium (genera of Aroideae) Commelina and Aneilema, Calamus and Seaforthia, Hellenia a solitary Australian genus of Scitamineae, some genera of Rubiaceae, particularly Psychotria and Coffea, certain genera of Asphodeleae, as Cordyline, and a genus allied to it, whose fructification is at length obtained, a solitary plant of Melastomeae, and an individual Nymphea.

Other genera also, but little influenced by those local circumstances of situation on the East Coast, that are excluded from the opposite shores, are Leucopogon (the only equinoctial genus of Epacrideae observed during the late voyages) the families Bignoniaceae, Jasmineae, the genus Erythrina, and of Coniferae, Araucaria of Norfolk Island.  This absence of several orders of plants on the north-western shores, existing in New South Wales, or opposite coast, as well as the consideration (at the same time) of the evident causes of such a disparity of species on the former coast, would suggest the opinion, that such