XE^V HOLLAND IN EUROPE. 45 
Eut even by thus limiting the climate of Europe during the Eocene 
period we have not proved more than that this part of the world could 
possibly support a vegetation which required a much milder climate. 
To us it is more important to ascertain how the vegetation of a conti- 
neutj situated at our very antipodes, coidd find its way hither. It is 
comparatively easy to account for the spreading of the plants of an ad- 
jacent milder cliumte to our northern zone, or to comprehend how 
the plants of a northern subtropical region came to us; but the oc- 
currence of representatives of the southern hemisphere in the northern 
certainly demands a very peculiar set of conditions. 
If not able to solve this geographical problem, I will, at all events, 
endeavour to advance its solution by studying geogi*aphy, prehistoric 
geogi'aphy though it be, bv the assistance of botany. About a year 
ago I endeavoured to deal with a similar problem. It was necessary to 
explain how it came to pass that at a time when lignite was formed 
(?, e. in the Molasse or Miocene period, more reeent tlian the one now 
spoken of) the plants agreed in such a striking manner with those of 
the southern parts of North America. An examination of this singu- 
lar phenomenon showed that it can only be explained by assuming 
a direct coimection of two continents now^ widely separated. Sufficient 
help was derived from geology to make this assumed connection pro- 
bable, andj curiously enough, an ancient tradition about the sinking of 
the island of Atlantis came to onr aid.* 
But how does the case stand with respect to the connection of Eu- 
rope and New Holland, at a period long previous to that of the Miocene ? 
Has any continental connection between these two quarters of the globe 
been possible or probable? Are there any proofs similar to those 
by which we supported the former connection between Europe and 
America? None whatever; moreover, geological investigations re- 
specting this point are still so unsatisfactory that we gain no support 
from them in this instance. We are here in the same predicament as 
in that question ; to explain a contemporaneous and homologous vege- 
tation in two such extensive corners of the globe nothing remains 
but to assume the existence of several centres of creation, or the 
transmission from one locality to the other of the greater part of these 
» 'The Sunken Island of Atlantis,' Journ. of Bot. 1865, p. 12. I must here 
draw attention to an important historical paper bearing on the subject. " Ame- 
rikas Entdectung im Alterthiun/' in Kriiger's 'Nordische Bliitter/ 1858, pp. 
213-263. 
