Dispersal of Herbaceous A agio sperms. 583 
of which the flora is largely Malayan and tropical, was left out of con- 
sideration. The results of this analysis are briefly set forth in the following 
table: 
Indigenous species : 
Total Species . 
Herbs. 
% Herbs . 
Australia (excluding Northern Territory) 
5,7” 
i,74i 
624 
30 
Queensland 
1,786 
1,833 
35 
New South Wales 
640 
35 
New South Wales (Moore) 
2,352 
843 
35 
Victoria ........... 
1,186 
683 
54i 
45 
Tasmania 
323 
47 
Western Australia 
2,578 
614 
24 
Non-endemic species 
586 
361 
62 
Endemic species of non-endemic genera . . 
1,101 
703 
64 
Species of the 398 endemic genera . . . 
4,024 
677 
i7 
The larger part of Australia, and that which supports by far the 
greatest number of species, is outside the tropics, and the characteristic 
vegetation of the continent flourishes under climatic conditions somewhat 
like those in the southern United States. The climate of Tasmania, on the 
extreme south, is very similar to that of England. Despite this temperate 
character of the climate, however, woody plants are very much more 
abundant than in the corresponding regions of the northern hemisphere, 
constituting from 50 per cent, to 75 per cent, or more, instead of from 
12 per cent, to 25 per cent., of the dicotyledonous vegetation. Tasmania 
has more than four times as great a proportion of woody plants as Great 
Britain. The flora of the endemic genera contains a still smaller percentage 
of herbaceous plants. 
The flora of Australia, therefore, strongly resembles that of a typical 
oceanic island, since woody plants form a comparatively large part of the 
indigenous vegetation, and an overwhelming part of the endemic. This 
renders it probable that the predominance of woody forms in both regions 
is due to the same cause. We have suggested that the greater part of 
the herbaceous flora of the world has had its origin in the land-mass of the 
northern hemisphere during Tertiary time, as an adaptation to the pro- 
gressive refrigeration of the climate, and that subsequently it has spread 
thence over all the accessible parts of the globe. Oceanic islands or other 
isolated regions which were not open to copious immigration would thus be 
expected to show a predominance of the ancient woody vegetation. Such 
an hypothesis, which easily accounts for the paucity of herbs in the vegeta- 
tion of oceanic islands, explains the same phenomenon in the flora of the 
island continent of Australia. All the evidence at hand seems to indicate 
that there has been no unbroken land connexion between this continent and 
Asia since early Tertiary times. The immigration of northern vegetation 
has consequently been greatly hindered ; but plants can cross much wider 
oceanic barriers than can most land animals, and it is therefore not surprising 
to find a considerable number of genera in Australia which are obviously 
