290 Prof. Gray's Address before the 
and in the subsaline vegetation there are some close alliances 
with the flora of the steppes of Siberia. And along the crests 
of high mountain ranges the arctic-alpine flora has sent south- 
ward more or less numerous representatives through the whole 
length of the country. 
If we now compare, as to their flora generally, the Atlantic 
Uhited States with Japan, Mandchuria, and Northern China, 
2. e., Hastern North America with Eastern North Asia—half the 
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Mandchuria, along with many other peculiar plants divided be- 
wo. ere are plants enough of the one region 
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even most of the genera and species which are peculiar to North 
erica as compared with Europe, and largely peculiar to 
Atlantic North America as compared with the Californian region, 
are also represented in Japan and Mandchuria, either by identi- 
cal or by closely similar forms. The same rule holds on a more 
northward line, although not so strikingly. If we compare the 
plants, say of New England and Pennsylvania (lat. 45°—AT’) 
with those of Oregon, and then with those of North 
Asia, we shall find many of our own curiously repeated in the 
latter, while only a small number of them can be traced along 
the route even so far as the western slope of the Rocky Moun 
tains. And these repetitions of Eastern American types 1? 
Japan and neighboring districts are in all degrees of likeness: 
character; sometimes the two would be termed marked vate 
ties i they grew naturally in the same forest or in the same 
region ; sometimes they are what the botanist calls re resentar 
tive species, the one answering closely to the other, but wit 
some differences regarded as specific; sometimes the two ar@ 
merely of the same genus or not quite that, but of a single or 
very few species in each country,—when the point which mee = 
ests us is that this eters limited type should occur in tw? 
antipodal places and nowhere else. 
