114 
ORIGIN OF LIFE IN AMERICA 
In a later chapter I shall mention many of these. I would 
only here draw attention to a striking botanical example 
which seems to me due to direct migration from Europe to 
western North America and not by way of Bering Strait. 
Anemones are so much cultivated now in gardens that 
almost everyone is familiar with them. Their geological 
history no doubt has been a very remarkable one. Not a 
single fossil anemone is known to science, because the plant 
contains no part that might readily be preserved, and yet it 
can be asserted that the genus must have originated in very 
remote times. The occurrence of many species in isolated 
mountain regions, the extremely discontinuous and wide 
range of others, and especially the high percentage of 
endemism, clearly imply that we have to deal with an ancient 
genus. Dr. Ulbrich,* to whom we are indebted for a splendid 
monograph of the genus Anemone, is of opinion that some 
of its sections were already developed in early Tertiary times. 
His view is, of course, entirely derived from what we might 
call circumstantial evidence, just as Dr. Stejneger’s was in 
regard to the age of the genus Cinclus. One of these species 
of anemone (A. baldensis), a well-known alpine plant, is, 
according to Dr. Ulbrich, probably of Miocene age. It grows 
also in the Carpathians, the Apennines, the Pyrenees and 
northern Spanish Mountains, but nowhere in Asia. Never¬ 
theless, the same species occurs in the highest elevations of 
the Sierra Nevada in California, in the Cascade and Rocky 
Mountains. A very closely-allied form of anemone (A. teto- 
nensis) lives at a height of over 10,000 feet in Idaho, and 
another (A. jamesoni) at about the same elevation in the 
Andes of Ecuador. All these nearly related forms, there¬ 
fore, are confined to Europe and western America. 
Among all the older American forms both of animals 
and plants, other possible routes of migration besides the 
Bering Strait one have to be taken into consideration. Re¬ 
turning to the birds again, it seems to me that the genus 
Regulus to which the European golden-crested wren belongs, 
must have entered North America in Pliocene times along 
with the great mammals alluded to in the last chapter. In 
* Ulbrich, E., “ Geograph. Verbreitung d. Gattung Anemone,” p.325. 
