222 ESSAYS. 
comparatively small area, not only most coniferous trees, but 
a notably larger number of trees altogether than any other 
part of the northern temperate zone? Why should its only 
and near rival be in the antipodes, namely, here in Atlantic 
North America? In other words, why should the Pacific and 
the European forests be so poor in comparison, and why the 
Pacific poorest of all in deciduous, yet rich in coniferous 
trees ? 
The first step toward an explanation of the superior rich- 
ness in trees of these antipodal regions, is to note some strik- 
ing similarities of the two, and especially the number of 
peculiar types which they divide between them. The ulti- 
mate conclusion may at length be ventured, that this richness 
is normal, and that what we really have to explain is the ab- 
sence of so many forms from Europe on the one hand, from 
Oregon and California on the other. Let me recall to mind 
the list of kinds (7%. e. genera) of trees which enrich our At- 
lantic forest but are wanting to that of the Pacific. Now al- 
most all these recur, in more or less similar but not identical 
species, in Japan, north China, ete. Some of them are like- 
wise European, but more are not so. Extending the com- 
parison to shrubs and herbs, it more and more appears, that 
the forms and types which we count as peculiar to our At- 
lantie region, when we compare them, as we first naturally 
do, with Europe and with our West, have their close counter- 
parts in Japan and north China; some in identical species 
(especially among the herbs), often in strikingly similar 
ones, not rarely as sole species of peculiar genera or in related 
generic types. I was a very young botanist when I began to 
notice this; and I have from time to time made lists of such 
instances. Evidences of this remarkable relationship have 
multiplied year after year, until what was long a wonder has 
come to be so common that I should now not be greatly sur- 
prised if a Sarracenia or a Dionza, or their like, should turn 
up in eastern Asia. Very few of such isolated types remain 
without counterparts. It is as if Nature, when she had 
enough species of a genus to go round, dealt them fairly, one 
at least to each quarter of our zone; but when she had only 
