132 ESSAYS. 
ing the few cases which point in the opposite direction (e. q: 
Eriocaulon septangulare, Spartina, Subularia, Betula alba), 
the general statement will be seen to be well sustained. Also, 
in the “Journal of the Proceedings of the Linnzan Society,” 
ii. p. 84, Mr. Bentham “calls to mind how frequently large 
American genera (such as Eupatorium, Aster, Solidago, Sola- 
num, ete.) are represented in eastern Asia by a small number 
of species, which gradually diminish or altogether disappear 
as we proceed westward toward the Atlantic limits of Europe ; 
whilst the types peculiar to the extreme west of Europe (ex- 
cluding of course the arctie flora) are wholly deficient in 
America. These are among the considerations which suggest 
an ancient continuity of territory between America and Asia, 
under a latitude, or at any rate with a’ climate, more merid- 
ional than would be effected by a junction through the chains 
of the Aleutian and the Kurile Islands.” 
I shall presently state why connection in a more meridional 
latitude need not be supposed. 
The deficiency in the temperate American flora of forms at 
all peculiar to western Europe is almost complete, and is most 
strikingly in contrast with the large number of eastern 
American forms repeated or represented in eastern Asia. Of 
genera divided between eastern North America and Europe, 
I can mention only Ostrya, Narthecium, Psamma, the mari- 
time Cakile, and perhaps Scolopendrium. Hottonia might 
have been added, but for a species accredited to Java. And 
if we extend the range across our continent, we add only 
Cercis and Leeflingia. Of the ampler genera at all charac- 
teristic of the European flora, I can enumerate from the flora 
of the northern United States nothing more important than 
Helianthemum and Valerianella, two or three species of each 
(but those of the former hardly congeners of the European 
ones), adding that Hieracia and perhaps Cirsia are somewhat 
more plentiful in eastern than in western America. Let it 
also be noted, that there are even fewer western European 
types in the Pacific than in the Atlantic United States, not- 
withstanding the similarity of the climate ! 
That representation by allied species of genera peculiar or 
