The Republican. [volume] (Oakland, Md.) 1877-current, 1888-05-05

have inspected the soil within virgin
forests, the earth is occupied by a host
of larval insects, principally belonging
to the group of beetles, but including
also many orthOpterOus insects. These
creatures in the course of their life I'M
foreground displace a good deal Of soil,
a portion of which is thrown upon the
surface, the greater part, however, be-
ing merely dislodged beneath the sur
face. The effect, however, is to COM
mingle and to break up the soil, and
| thus favor its communion. Although
the roots of trees do by far the larger
part of the rending which is accom-
plished in the soil layer. they do not
bring about much commingling of the
soil. The thrusts which they apply to
| it shear the materials about, and so to
a certain extent mix them, but by far
the larger part OF the commingling is
effected by the animal life which dwells
beneath the forest bed.
Where the woods are wet and favor
the development of the crayfsh the
effect of this group of animals on the
overturning of the soil is extremely
great 1t probably exceeds that which
is accomplished in our ordinary fields
by the action of the earth-worms. A
single crayfsh will often bring in the
course of single seasons activity not
less than half cubic foot of earthly
matter to the surface. In certain dis
tricts where these animals abound there
| appear TO be not less than thousand
TO each acre of surface. If such be
their number, it is evident that not less
| than five hundred cubic feet of matter
is brought to the surface from q con-
siderable depth in the course of year.
As this matter is generally of Il rather
fine nature and easily dissolved in water,
itrapidly washes away and forms IL thin
sheet on the surface. / am inclined to
believe that large areas of our wet
woods and the open border lands along
our streams are completely overturned
to the depth of two feet or more
in the course of half century
by the actions of these animals.
1t is not impossible, indeed. that
the very fine division of the soil
which characterizes the regions inhab-
tied by these creatures may be in good
part due to their action. In this man
ner the creatures may have in part
worked to bring about the very condi-
tons which best serve their needs. "ln
open grounds, in natural prairies or
grass-plains, the smaller species of ants
are extremely effective agents in over
turning the spoils. Wherever the
ground remains for some time uu-
plowed, it becomes occupied by those
creatures. In the sandy soils of East
ern Massachusetts, the overturning ac-
complished by these creatures assumes \
geological Importance. For many years
| have been puzzled by the fact that the
glacial terraces and plains of this re-
gion were extensively covered to the
depth of q foot or more by Il coating
of fine sand and very small pebbles,
while below the depth of foot pebbles
of larger size are very numerous and
the spaces between them but imper-
fectly occupied with any material. 1t
is obviously impossible to explain these
conditions through the action of earth.
worms, for the reason that these crea-
lures are rarely found in soils of this
description. From much observation l
have become convinced that this coat
ing of sandy material is to q great ex-
tent to be explained by the action of
various species of ants, in the forest
condition by the work of the larger
black ants, and in the condition of open
plains by that of the smaller species.
The amount of material which these
creatures bring to the surface in
single season is surprising. At several
points in Eastern Massachusetts, | have
found the surface to contain at least
one ant-hill to each square foot of area,
or about forty thousand hills to the
acre. This is probably an exceptionally
great number; it will perhaps be safer
to estimate the number at twenty thou
sand to the acre. The incoherent heaps
OF excavated matters which these crea-
lures form are quickly washed away by
the rain, or in many eases are blown
away by strong winds. and so scat
tered over the surface. AS soon as de-
stroyed they are, in most cases, re-
builded, the result being that a single
hill is reconstructed at least half u
dozen times during the season. have
estimated that the amount Of material
brought to the surface often exceeds
three cubic inches to each square foot
of surface in single year, or about u
fiftieth of an inch of the whole area
each year. Thus, in the term of fifty
years, the accumulation of material on
the surface would amount to as much
as an inch and, reckoning the soil as
having an average depth Of one foot, a
total overturning would be accom-
plished in less than one thousand years.
1t is likely that in some cases, over con-
siderable areas, a tolerably complete
overturning is brought about in less
than quarter of this time.
The effect of this action of ants on
the soil material is peculiar. The ten
dency is like that noted by DR.. Darwin