1877.] The Geographical Distribution of Animals. 159 
willows, planes, alders, dogwood, and cypress, together with 
such American forms as magnolias, sassafras, and liriodendrons. 
There are also a few not now found in America, as Araucaria 
and Cinnamomum, the latter still living in Japan.. This remark- 
able flora has been found over a wide extent of country, New 
Jersey, Alabama, Kansas, and near the sources of the Missouri 
in the latitude of Quebec, so that we can hardly impute its pe- 
culiarly temperate character to the great elevation of so large an 
area. The intervening Eocene flora approximates closely in 
North America to that of the Miocene period, while in Europe 
it seems to have been fully as tropical in character as that of the 
preceding Cretaceous period, fruits of Nipa, Pandanus, Anona, 
Acacia, and many Proteacex occurring in the London clay at 
the mouth of the Thames. 
These facts appear, at first sight, to be inconsistent, unless we 
suppose the climates of Europe and North America to have been 
widely different in those early times; but they may perhaps be 
harmonized on the supposition of a more uniform and a some- 
what milder climate then prevailing over the whole northern 
hemisphere, the contrast in the vegetation of these countries be- 
ing due to a radical difference of type, and therefore not indica- 
tive of climate. The early European flora seems to have been a 
portion of that which now exists only in the tropical and sub- 
tropical lands of the eastern hemisphere, and as much of this 
flora still survives in Australia, Tasmania, Japan, and the Cape 
of Good Hope, it does not necessarily imply more than a warm 
and equable temperate climate. The early North American 
flora, on the other hand, seems to have been essentially the same 
ìn type as that which now exists there, and which in the Mio- 
cene period was well represented in Europe; and it is such as 
now flourishes best in the warmer parts of the United States. 
But whatever conclusion we may arrive at on the question of cli- 
Mate, there can be no doubt as to the distinctness of the floras of 
the ancient Nearctic and Palzarctic regions; and the view de- 
rived from the study of their existing and extinct faunas — that 
these two regions have, in past times, been more clearly sepa- 
tated.than they are now — receives strong support from the unex- 
pected evidence now obtained as to the character and mutations 
of their vegetable forms, during so vast an epoch as is comprised 
ìn the whole duration of the Tertiary period. 
The general phenomena of the distribution of living animals, 
Combined with the evidence of extinct forms, lead us to conclude 
