232 ESSAYS. 
The still greater richness of northeast Asia in arboreal 
vegetation may find explanation in the prevalence of particu- 
larly favorable conditions, both ante-glacial and recent. The 
trees of the Miocene cireumpolar forest appear to have found 
there a secure home; and the Japanese islands, to which 
most of these trees belong, must be remarkably adapted to 
them. The situation of these islands — analogous to that of 
Great Britain, but with the advantage of lower latitude and 
greater sunshine, — their ample extent north and south, their 
diversified configuration, their proximity to the great Pacific 
gulf-stream, by which a vast body of warm water sweeps 
along their accentuated shores, and the comparatively equable 
diffusion of rain throughout the year, all probably conspire to 
the preservation and development of an originally ample in- 
heritance. 
The case of the Pacific forest is remarkable and paradoxi- 
eal. It is, as we know, the sole refuge of the most charac- 
teristic and widespread type of Miocene Conifera, the Se- 
quoias; it is rich in coniferous types beyond any country 
except Japan; in its gold-bearing gravels are indications that 
it possessed, seemingly down to the very beginning of the 
Glacial period, Magnolias and Beeches, a true Chestnut, 
Liquidambar, Elms, and. other trees now wholly wanting to 
that side of the continent, though common both to Japan and 
to Atlantic North America.1. Any attempted explanation of 
this extreme paucity of the usually major constituents of for- 
ests, along with a great development of the minor, or conifer- 
ous, element, would take us quite too far, and would bring us 
to mere conjectures. 
Much may be attributed to late glaciation ;* something to 
the tremendous outpours of lava which, immediately before 
1 See, especially, “ Report on the Fossil Plants of the auriferous gravel 
deposits of the Sierra Nevada,’’ by L. Lesquereux ; “ Mem. Mus. Comp. 
Zoodlogy,’’ vi. No. 2.— Determinations of fossil leaves, ete., such as these, 
may be relied on to this extent by the general botanist, however wary of 
specific and many generic identifications. These must be mainly left to 
the expert in fossil botany. 
2 Sir Joseph Hooker, in an important lecture delivered to the Royal 
Institution of Great Britain, April 12, insists much on this. 
