astward and have extended the forest areas in that
direction. Freshets, floods, and overflows have been even more active in
carrying seeds, sprouts, and even trees into new territories. Waves and
currents have likewise played a similar part. Wherever the soil of the
region into which the species have been carried is moist and nutritious,
the forest growth has usually extended.

=The Pine Family.=--The pine family includes the various species of pine,
tamarack, spruce, hemlock, fir, juniper, larch, cypress, and cedar. A
few members of the family thrive in the warmer parts of the temperate
zone, but for the greater part they flourish between the fortieth and
sixtieth parallels. Most of the species found in low latitudes are
mountain-trees. They constitute the greater part of the American and
Russian forests. The American pine forest is thought to be the largest
in the world.

The _white pine_ (_Pinus strobus_) is the most valuable member of the
family. Its value is due in part to the fact that the wood is soft,
clear, and easily worked, and in part to the accessibility of the
forests. Not much inroad has yet been made upon the great Russian
forest, owing to the fact that the timber is too far away from seaports
and water transportation. Rough lumber becomes too expensive for use
when transported by land, but it will stand the expense of shipment by
water many miles.

The _Georgia_ or _long-leafed pine_ (_Pinus palustris_) is also
commonly called _pitch pine_, _turpentine pine_, and _southern pine_; it
grows chiefly along the south Atlantic coast and in the northern
counties of Georgia. It is harder than white pine and makes excellent
flooring.

The _sugar pine_ (_Pinus lambertiana_) occurs mainly in Oregon and
California. The grain is fine and soft and the trees reach a large
girth.

The _loblolly pine_ (_Pinus taeda_) has a considerably larger area than
the Georgia pine, extending into Indian Territory. The _short-leaf pine_
(_Pinus echinata_) occurs in small areas from New York to the Gulf of
Mexico, and across to Missouri; it is the Chattahoochee pine of Florida.
The _pitch pine_ (_Pinus rigida_) occurs in various areas mainly north
of the Ohio River and west of the prairies. The lumber cut annually from
these pines aggregates about thirty billion feet.

The common _white cedar_ (_Chamaecyparis thyoides_) occurs along the
Atlantic and Gulf coasts nearly to the Mississippi. On account of its
fine grain it is muc