148 ESSAYS. 
through a few generations, the traditions of centuries, and so 
tell us something of the history of their race. Fifteen hun- 
dred annual layers have been counted, or satisfactorily made 
out, upon one or two fallen trunks. It is probable that close 
to the heart of some of the living trees may be found the 
circle that records the year of our Saviour’s nativity. A few 
generations of such trees might carry the history a long way 
back. But the ground they stand upon, and the marks of 
very recent geological change and vicissitude in the region 
around, testify that not very many such generations can have 
flourished just there, at least in an unbroken series. When 
their site was covered by glaciers, these Sequoias must have 
occupied other stations, if, as there is reason to believe, they 
then existed in the land. 
I have said that the Redwoods have no near relatives in 
the country of their abode, and none of their genus anywhere 
else. Perhaps something may be learned of their genealogy 
by inquiring of such relatives as they have. There are only 
two of any particular nearness of kin; and they are far away. 
One is the Bald Cypress, our southern Cypress (Taxodium), 
inhabiting the swamps of the Atlantic coast from Maryland 
to Texas, thence extending — with, probably, a specific differ- 
ence — into Mexico. It is well known as one of the largest 
trees of our Atlantic forest-district, and although it never — 
except perhaps in Mexico, and in rare instances — attains the 
portliness of its western relatives, yet it may equal them in 
longevity. The other relative is Glyptostrobus, a sort of modi- 
fied Taxodium, being about as much like our Bald Cypress as 
one species of Redwood is like the other. 
Now species of the same type, especially when few, and the 
type peculiar, are, in a general way, associated geographically, 
i. €., inhabit the same country, or (in a large sense) the same 
region. Where it is not so, where near relatives are sepa- 
rated, there is usually something to be explained. Here is an 
instance. These four trees, sole representatives of their tribe, 
dwell almost in three separate quarters of the world: the two 
Redwoods in California, the Bald Cypress in Atlantic North 
America, its near relative, Glyptostrobus, in China, 
