i86 
AMERICAN JOURNAL OF BOTANY 
[Vol. io. 
The region which shows most similarity to West Australia in its flora is 
the Cape region of South Africa. There is a similar development of Pro- 
teaceae, as well as certain Compositae common to the two, and the true 
heaths (Ericaceae) of the Cape are very similar in many respects to the 
Australian Epacridaceae. There are, however, many differences, and any 
land connections that may have existed must have disappeared at a very 
remote period. There is clear evidence of a connection of all the southern 
land masses in the Permian—the so-called “Gondwana Land,” but the 
evidences for later connections are, at present, more or less problematical. 
However, it seems pretty certain that some connection between South 
Africa and Australia did exist, perhaps in the Tertiary, and that there is 
a real relation, although remote, between their floras. 
It may be that further investigation will show that in the Tertiary, as 
was the case in the northern hemisphere, there was a practically uniform 
flora, occupying a more or less continuous land mass connecting the now 
widely separated regions of South America, Australia, and South Africa. 
It is possible that the common elements in the floras of Australia and South 
Africa are descendants of this ancient flora, which through long isolation 
have diverged from each other. 
The complete isolation of Western Australia has resulted in a remarkable 
degree of specialization among a relatively small number of original types, 
with almost no admixture of immigrants subsequent to the severing of the 
connection of Australia with the land to the south. 
EXPLANATION OF PLATES 
Plate XXI 
Fig. i. Tree ferns, Botanical Gardens, Melbourne. 
Fig. 2. Banksia grandis, Perth. 
Fig. 3. Chaparral formation, National Park, Victoria. The trees are Casuarina sp. 
Fig. 4. Desert vegetation, transcontinental railway. 
Fig. 5. Coastal vegetation, Perth. The largest tree is a red gum (Eucalyptus calo- 
phylla ). 
Plate XXII 
West Australian grass trees (Xauthorrhoea reflexa). Photograph furnished by Mr. C. 
E. Lane-Poole. 
