COLOKIAL FLORAS. 
505 
In point of area the Australian Flora is much the largest, ex¬ 
tending from Lat. S. 10° to 44° and Long. E. 113° to 153°: the Cape 
Flora embracing only from Lat. S. 23|° to 34 \° and Long. E. 
from 15° to 35°. The Australian Flora includes a considerable 
tropical area, which the South African does not; but this is met in 
part by the facts that many more tropical African plants extend 
beyond the tropic of Capricorn in Africa than Asiatic plants do 
beyond the same tropic in Australia ; and that the Australian tropi¬ 
cal Flora is an extremely poor one. On the other hand a vast number 
of desert tropical forms extend in both the Australian and South 
African regions to very high South Latitudes, namely, to 
Adelaide in Lat. 35° and to Lat. 30° in South Africa. 
Then with regard to the comparative temperatures of the Austra¬ 
lian and South African areas under consideration, the isotherm of 60°, 
which passes through South-East and South-West Australia, 
also touches the Cape of Good Hope, near Cape Town; whilst the 
isotherm of 70° cuts the tropic of Capricorn obliquely in each conti¬ 
nent. The average rain-fall is about the same in extra-tropical 
Southern Africa and Australia, and the equatorial limit of the fall of 
snow at the level of the sea passes through the Cape Colony and that 
of Victoria in Australia. Here then are certain very marked physical 
features common to Australia and South Africa; to which may be added, 
that the average amount of mountain area is not widely different in 
each, that in both the Alps reach about the same elevation, and in both 
areas there is a most striking difference between the vegetations of 
their Eastern and Western halves. This latter difference, though 
coincident with some climatic differences, is far greater than is found 
to obtain between Eastern and Western Europe, where much greater 
climatic differences prevail. The main difference between the two 
countries is however in area, that of the Cape Flora being less than 
one fourth of the Australian, and perhaps more exactly representing 
in extent and conditions the colonies of Queensland, New South 
Wales, and Victoria. 
Proceeding now to compare the volumes, we have in Australia 39 
Orders, from Banunculacese to before Leguminosse, and in the Cape 
40 the ordinal differences between the Floras being the presence 
in Australia only of in the Cape only of 
Dilleniaceae. 
Magnoliaceae. 
Tremandreae. 
Guttiferae, 
Simarubeae. 
Stackhousieae. 
Of genera there are 
Of species „ 
Eesedaceae. 
Tamariscineae. 
MeliantheaB. 
Chailletiaceae. 
Connaraceae. 
Australia 243, Cape 165. 
„ 1072, „ 1316. 
* A correction is here introduced for certain Orders in the Cape Flora ranked 
as sub-orders in the Australian; and for a few Orders being included as Thalamiflorac 
in the Cape Flora, but referred to other divisions in the Australian, or vice versa . 
