THE FLORA OF SOUTH AUSTRALIA. 67 
not extend the limits of the flora farther than the 34th degree of south 
latitude, the proportion becomes as 7 : 2, and therefore holds the mean 
between the proportions which prevail in Van Diemen's Land and 
New South Wales; while in Western Australia (nearly agreeing with 
the more extended observations here) the number of Monocotyledons 
is surpassed more than fourfold (2 : 9), and the Acotyledons more than 
sixfold, by the Dicotyledons. 
The Composite and Leguminose here exceed numerically all other 
families, to so great a degree, that taken together they embrace nearly 
one-third of the Dicotyledons, and in the southern districts actually 
form more than one-fifth of the entire vegetation ; indeed, if we extend 
the limits of our comparison back to the subtropical districts, they 
compose nearly one-fourth of the entire flora. Of this the Composite 
alone constitute one-eighth, a proportion which is higher than in any 
other part of Australia, and little less with reference to the entire mass, 
than it is in South Africa. Van Diemen's Land participates most in 
this superabundance of Composite. 
These comparisons, it is to be observed, were instituted in a level 
district, which corresponds tolerably well with that of Tasmania, and 
founded on collections from such tracts of land as show the most 
strongly marked contrasts, namely, in Western Australia, between the 
Swan River and King George’s Sound; and in the east, between the 
33rd and 36th degree of south latitude. 
We must not however place too implicit reliance upon the numerical 
proportions here set forth, but rather regard them for the present as 
approximative only, since, even in the regions of Australia just com- 
pared, whose flora we have only learnt to know with the present cen- 
tury, there is a residue too important to be left out of consideration ; 
moreover, the difficulty of instituting a comparison is much increased 
by the want of a general work on the plants of this fifth continent, 
until the appearance of which the attempt to take a comprehensive 
view will remain greatly disturbed. 
The entire number of species indigenous to the province of South 
Australia, I estimate at not much less than 2000; of which up to this 
time between 1300 and 1400 have been discovered. But to these, 
nearly 100 species are already to be added, which, having migrated, 
partly from Europe, partly from the Cape, have become naturalized 
here, beyond the possibility of extirpation. Probably, too, the number 
