xhii INTRODUCTION. 
Japan to the continent. This is so in the latitude of Peking; but the more southern 
province of Hupeh, for instance, would show a much higher percentage than Peking, 
and possibly even higher than Japan, inasmuch as the Polypetale of the whole of China 
proper, so far as known *, contain 41°34 per cent. of endemic species, and there is no 
doubt that the further exploration of the interior provinces will materially raise this 
percentage. 
Maximowicz very elaborately analyses the affinities of the endemic species in the 
areas named, from which it appears that it is only in Japan that there is a considerable 
development of endemic species of what he terms the Chinese type. On the other 
hand, the “levantine type” is apparent in 13°9 per cent. of the endemic species of 
Mongolia. To be brief, Maximowicz sums up this question in words to the effect that 
the plants of the plains of Northern and Central Europe constitute the greater part of 
the flora eastward to the Pacific coast, if not in identical forms, at least by forms 
connected by intermediates with European species f. 
It would carry us too far to attempt to give the exact eastern limits of the Mediter- 
ranean region in Asia, as it would involve a discussion of the vegetation of the various 
provinces of this subregion. The southern limits of the northern region in the Old 
World may be indicated approximately as the tropics, varying in different longitudes. 
‘It includes the alpine and temperate Flora of the Himalayas, and in Africa it extends 
to the Great Atlas f. 
The subregions of the northern region in the New World are five, namely :—Arctic, 
Boreal, Atlantic, Central, and Pacific, which may be roughly defined. Briefly the 
Arctic is a continuation of the same subregion in the Old World; the Boreal is a 
westward extension of the hardier elements of the Atlantic subregion, and perhaps 
better regarded as a province of it; the southern or Mexican province of the Central 
subregion is fully described in the Appendix; and further particulars of the characteristics 
of the whole Rocky-Mountain Flora will be found in the joint essay, by the late Dr. A. 
Gray and Sir Joseph Hooker, previously cited. The distribution of the North-American 
Flora generally is admirably summarized by the latter §, who distinguishes the Sink 
country between the Rocky Mountains and the Sierra Nevada as a separate Flora, while 
admitting that cacti and yucca attain their maximum development further south in the 
same meridian. Professor Sargent describes his northern forest-region as extending 
southward to the fiftieth parallel on the Atlantic coast and to the fifty-fourth at the 
hundredth meridian ||. 
* « Index Flore Sinensis,”’ Journ. Linn. Soc. xxiii. 
+ Ina recent collection of about 500 species, made in Mandshuria by Mr. H. E. M. James, nearly a third 
are British species (see ‘ Proceedings of the Royal Geographical Society,’ 1887, p. 548). 
t For an account of the vegetation of these mountains consult Hooker and Ball’s ‘ Tour in Morocco,’ 1878. 
§ Proceedings of the Royal Institution of Great Britain, 1878. 
|| Report on the Forests of North America, p. 3. 
