20 
POPULAR SCIENCE REVIEW. 
by Dr. Unger, of Vienna, one of the most distinguished and 
cautious of leading botanical palaeontologists, to account 
for the similarity, not to say identity, of vegetable forms 
existing in the Eocene beds of Europe and the present flora 
of Australia. Dr. Unger employs, in his essay on this subject 
[Journal of Botany , British and Foreign , vol. hi. pp. 39-70), 
the same method by which he proved so satisfactorily the 
former existence of the island of Atlantis [Journal of Botany , 
iii. p. 12), and it may be interesting to give here the result 
of his labours, adding such observations as may suggest 
themselves. 
New Holland and the neighbouring islands are characterized 
by a vegetation at present not met with in other parts of the 
world. Several natural orders and genera of plants are there 
found in such overwhelming majority that the vegetation 
derives from them its distinguishing character. There are, 
for instance, certain Myrtaceous plants — Eucalypti, or gum- 
trees — diffused over New Holland in such numerous species, 
and the species represented by such innumerable individuals, 
that they alone determine the character and the condition of 
the forests. The same remark applies to a countless multitude 
of those heath-like plants, the Epacrids , which are to New 
Holland what the Ericas are to the Cape of Good Hope. The 
peculiarity of these trees and shrubs, and their abundance, 
have induced botanical geographers to designate the extra- 
tropical part of New Holland “the region of gum-trees and 
Epacrids.” But these are not the only types characteristic of 
this part of the globe : the Proteacece , Santalece , Monimiacece, 
and Anthobolece , are equally prominent. True, some of them 
have sent outposts to other continents, but their principal 
army is stationed in New Holland and the adjacent islands; 
the Proteacece especially are spread over the whole continent 
of Australia in numerous genera and species. Nor must we 
omit to mention several genera of Leguminosce and Coniferce. 
There are also the Acacias, with numerous species, and curious 
enlarged leafstalks, peculiar to the Australian types; and 
amongst the Coniferce , the genera Araucaria , Podocarpus , and 
partly Callitris. 
Let us now see how far these characteristic plants of New 
Holland are represented in our European Eocene formation. 
Not only do we meet with the polymorphous order Myrtacew , 
but it is plain the genus Eucalyptus itself is represented 
amongst the fossils. Of several species the peculiar leaves 
as well as the fruit have been found. The same is the 
case with the Epacrids. But much more stress has been 
laid upon the Proteacece, as the characteristic plants of 
the Eocene period, than the Myrtacece and Epacrids . We 
