FOREST GEOGRAPHY AND ARCHZOLOGY. 217 
nor a Hornbeam ; barely one Birch-tree, and that only far 
north, where the differences are less striking. But as to 
Coniferous trees, the only missing type is our Bald Cypress, 
the so-called Cypress of our southern swamps, and that de- 
ficiency is made up by otherthings. But as to ordinary trees, 
if you ask what takes the place in Oregon and California of 
all these missing kinds, which are familiar on our side of the 
continent, I must answer, nothing, or nearly nothing. There 
is the Madrofia (Arbutus) instead of our Kalmia (both really 
trees in some places); and there is the California Laurel 
instead of our southern Red Bay tree. Nor in any of the 
genera common to the two does the Pacific forest equal the 
Atlantic in species. It has not half as many Maples, nor 
Ashes, nor Poplars, nor Walnuts, nor Birches, and those it 
has are of smaller size and inferior quality: it has not half 
as many Oaks; and these and the Ashes are of so inferior 
economical value, that (as we are told) a passable wagon- 
wheel cannot be made of California wood, nor a really good 
one in Oregon. 
This poverty of the western forest in species and types may 
be exhibited graphically, in a way which cannot fail to strike 
the eye more impressively than when we say that, whereas the 
Atlantic forest is composed of sixty-six genera and one hun- 
dred and fifty-five species, the Pacific forest has only thirty- 
one genera and seventy-eight species. In the appended dia- 
grams, the short side of the rectangle is proportional to the 
number of genera, the long side to the number of species. 
Now the geographical areas of the two forests are not very 
different. From the Gulf of Mexico to the Gulf of St. Law- 
rence about twenty degrees of latitude intervene. From the 
southern end of California to the peninsula of Alaska there 
1 We take in only timber trees, or such as attain in the most favorable 
localities to a size which gives them a clear title to the arboreous rank. 
The subtropical southern extremity and Keys of Florida are excluded. 
So also are one or two trees of the Arizonian region which may touch the 
evanescent southern borders of the Californian forest. In counting the 
coniferous genera, Pinus, Larix, Picea, Abies, and Tsuga are admitted to 
this rank, but Cupressus and Chamecyparis are taken as one genus. 
