ofS.E. $ S.W. Australia.] 
INTRODUCTORY 
*Adenantho3 . 
♦Beaufortia 
*Agonis . . 
Phebalium . . 
♦Hypocalymna 
Trachymene . 
Podolepis . . 
♦Anarthria . . 
Opercularia 
Myoporum . 
Atriplex . . 
Caasytha . . 
Thelymitra 
' 
Ealoragia 
*Aatartea 
Hclichrysum 
•Halgatiia . 
*Microcorys 
Rhagodia 
*Synnphea . 
Caauarma . 
*Viiniiiaria . 
Dportant differential features of south-< 
aye, and I ■would point out: — 1. ilou 
This instructive table puts the most i 
western Australia prominently before the 
genera of the south-western Flora are, there being SO genera with upwards of 10 species in its 
column, and only 55 in the south-eastern. 2. That the 55 genera of the south-eastern Flora contain 
about 1,260 species, and the 55 highest of the south-western 1, 7.-7 species. 3. That of these 55 south- 
Altogether, I find the proportion of genera to specie- in the south-weatern Flora to be l : 6, and 
in the south-eastern 1:1. This increased number of genera in south-eastern Australia over the 
south-western is mainly due to the presence of more Antarctic, European, New Zealand, and Poly- 
nesian genera in the south-east, to which I shall hereafter allude. 
The proportion of species belonging to peculiar or endemic genera in the south-west is about 
one- third of the whole, and in the south-east one- sixth. 
The proportion of species common to other countries in the south-west is about one-tenth 
of the Flora, and in the south-east one-sixth. 
There are about 180 genera, out of about GOO, in south-western Australia that are cither not 
found at all in south-eastern, or that are represented there by a very few species only, and these 180 
genera include nearly 1,100 species. 
Of generally diffused Australian genera that are absent in the south-west, 1 find Viola, Poly gala, 
Epacris, Lycopiis, Aj/u/a, Smilax, and Eriocaulon ; and of European genera which occur in that 
/•;*■/ 
Orobanche, AUhema, and Lrptvms, several of which I suppose to be introduced, and, if so. will 
soon be found in other colonics. 
This curious case of great differences in the genera and species of the two quarters of a small 
continent, accompanied by an increased number of species in the -mailer and more isolated quarter 
of the continent, which is, further, by far the most uniform in physical conditions, will no doubt 
eventually be found to offer the best means of testing whatever theory of creation and distribution 
may be established. In the meantime, the theories which I have sketched in the early pages of this 
Essay cannot, in the present state of our geological knowledge of Australia, be brought to bear 
fully upon it. That no Natural Order, but that many genera, and a whole Flora of species, should 
