ash of several kinds, elm, sugar maple, honey locust,
hackberry, linden, hickory, cotton wood, pecan, mulberry, buckeye,
sycamore, wild cherry, box elder, sassafras, and persimmon. In the
southern and eastern parts of the State are yellow poplar, and beech;
near the Ohio are cypress, and in several counties are clumps of yellow
pine and cedar. On the Calamick, near the south end of lake Michigan, is
a small forest of white pine. The undergrowth are redbud, pawpaw,
sumach, plum, crab apple, grape vines, dogwood, spice bush, green
brier, hazle, &c.

The alluvial soil of the rivers produces cotton wood and sycamore timber
of amazing size.

For ordinary purposes there is now timber enough in most parts of the
State, to say nothing about the artificial production of timber, which
may be effected with little trouble and expense. The black locust, a
native of Ohio and Kentucky, may be raised from the seed, with less
labor than a nursery of apple trees. It is of rapid growth, and, as a
valuable and lasting timber, claims the attention of our farmers. It
forms one of the cleanliest and most beautiful shades, and when in
blossom gives a rich prospect, and sends abroad a delicious fragrance.

6. _Knobs, Bluffs, Ravines, and Sink-holes._ Under these heads are
included tracts of uneven country found in various parts of the State.

_Knobs_ are ridges of flint limestone, intermingled and covered with
earth, and elevated one or two hundred feet above the common surface.
This species of land is of little value for cultivation, and usually has
a sprinkling of dwarfish, stunted timber, like the barrens.

The steep hills and natural mounds that border the alluvions have
obtained the name of _bluffs_. Some are in long, parallel ridges, others
are in the form of cones and pyramids. In some places precipices of
limestone rock, from fifty to one or two hundred feet high, form these
bluffs.

_Ravines_ are formed amongst the bluffs, and often near the borders of
prairies, which lead down to the streams.

_Sink-holes_ are circular depressions in the surface, like a basin. They
are of various sizes, from ten to fifty feet deep, and from ten to one
or two hundred yards in circumference. Frequently they contain an outlet
for the water received by the rains. Their existence shows that the
substratum is secondary limestone, abounding with subterraneous
cavities.

There are but few tracts of _stony ground_ in the State; that is, where
loose