cases to peculiarly Australian Orders or 
tabulating the genera and species of each 
of our knowledge, be very vague, they may 
Bnce, which it is all the more important to 
allcl in the geography of plants. These 
/,,■ S<iti//t-,i!s/< ,',./ Vlura, i admit mj Tasmania. 
Natural Orders .... 126 
Genera 700 
Species 3,000 
Distribution of Genera.] INTRODUCTORY 
genera belong to the same Natural Orders, and in ma 
divisions of Orders. 
I have endeavoured to estimate this difference 1 
country, and though the results must, in the present sta 
serve to give an approximate idea of the amount of din* 
do because I believe the phenomenon to be without a r 
Floras T estimate as containing about — 
South-icedrrn. 
Natural Orders .... 90 
Genera 600 
Species 3,000 
As far as I can make out, about one-fifth of the south-eastern species arc found beyond that 
area; but only one-tenth of them are found in south-western Australia. 
I need not remind my readers that these countries are in the same parallel of latitude, are not 
remarkably different in physical conditions, or indeed by any means so different as others Greece 
and Spain for example) that present no such contrast, 
only 1700 miles, with continuous land throughout. 
judging from analogy with other countries, favour the idea that south-eastern Australia, from its 
far greater area, many large rivers, extensive tracts of mountainous country and humid forests, -would 
present much the most extensive Flora, of which only the drier type- could extend into south-western 
Australia. Hut such is not the case altogether, for though the far greater area is much the best 
explored, presents more varied conditions, and is tenanted by a larger number of Natural Orders 
and genera, these contain fewer species by several hundreds. 
Of the largest genera of south-eastern and south-western Australia there arc very few species 
common to both countries, as the following list, arranged in order of their magnitude, will show * 
Grevillea 
Eucalyptu: 
Pultena-a 
South-eastern Australia. 
133 
Bp. 
uund in 

B.W. 
Melaleuca 
67 


Ilelichrysum 
Braehveome 
50 

Xerotes 
50 

Prasophylluui 
40 

Pterostylia . 
36 
1 
30 
Carei 
27 
1 

ist is very far from complet 
\ but 
, i„ so 
far founded on exa 
ct data as t 
Per*., 
satisfied myself 
of the whole number of species alluded to in the first column of figures being absent in the collections I ha 
examined from *outh-we-t Australia, except when otherwise stated. Future observations will no doubt modify i 
details without vitiating the general result. 
