48 NEW HOLLAND IN EUKOPE. 
coral reefs, but by lueaus of a continental highway tliat existed in the 
same place, that the Arancarias^ Pro(eace(Sy Santalem^ and numerous 
other arboreous and herbaceous plants still undetermined, reached our 
contiuent, where, after myriads of years, they are still preserved as fos- 
sils. The continental connection of Australia and Europe during the 
Eocene period is consequently a necessary assumption. But sup- 
posing that the highway indicated had been sufficiently practicable to 
permit masses of emigrants, to whom their native land in the south 
had become too limited, to reach Europe, the problem still remains, 
how did it come to pass that they could make so difficult a journey, 
extending over thousands of years, without obtaining on foreign Asia- 
tic soil conditions favourable to their existence ? Unfortunately, the 
geological investigations of that continent do, as yet, not enable us to 
make even a surmise, but it is certain the ranks of these Australian emi- 
grants were increased in Asia by a number of species which continued 
with them their onward march to Europe, — at that time, it should 
be remembered, not a cold country. In order to make my meaning 
clearer, I must state an important fact. It would be erroneous to 
believe that the Eocene beds contain only plants having an Australian 
character. Though such pi'edominate, they are accompanied by epecies 
which must have originated in a country far distant from Australia. 
We are forced to this conclusion from finding the genera and species 
allied to them only in Asia. Amongst such plants as are as character- 
istic of the latter continent, as Gum-trees, Araucarias, Proteacea, etc., 
are of New Holland, I instance the widely-diffused species of Ghjpto- 
drobm {G. Euroj;6eus, Brongn., and G, (Eningmsis, A, Braun), both 
of which but slightly differ from the species indigenous to Southern 
China (G. MeropJiyllm, EndL). Of decidedly Asiatic origin are the 
species of Ailanihus, occurring in the Eocene beds of Europe, of which 
two have been found {A, Confucii, Ung., in EadoboJ, and A, Gigas, 
Ung., in Sotka), whilst at present only four species exist,, all of which 
{A. excelm, Koxb., Malabarica, DC, Mohwcana, DC, and glandu- 
lom^ Desf.) are natives of Asia. Planeria Ungeri^ Ett., widely dif- 
fused in the Eocene and even in more recent beds, must also be 
regarded of Asiatic origin ; and we have further to add several Fio-g 
Oaks, Laurels, Jjegumimm^ and others. This shows incontrovertibly 
what I have already maintained, that the highway by which the 
New Holland plants passed to Europe led through Asia, and that 
