NOTES ON BIRD'S-EYE MAPLE.
W. J. BEAL.

THE wood of some trees of Sugar Maple, Acer saccharinum Wang,
on removing the bark is found to be irregularly covered with conical pits which are more or less rounded at the bottom. In many
instances these pits are irregular in outline; some are longest up and
down the tree, and not infrequently two or more are partially united.
The pits generally, though not always, have a depth equal to the
greatest diameter. The largest pits are about a quarter of an inch in
diameter and vary in size to the smallest, which can barely be seen
with the unaided eye.

If the wood be split parallel with the bark, the side of the stick so
removed toward the heart of the log will contain more or less conical
projections such as come from the pits left in the counterpart of the
block.

On removing the bark, numerous small cones are displayed on it,
such as descended and just filled the pits in the outer wood.

By examining many radial sections, one will frequently find instances where the "birds-eye" is just beginning, usually very small. From this beginning, the pits usually grow larger and broader as we
successively look at the older wood. Sometimes a pit runs of even
size for many years; sometimes it abruptly disappears as we view the
wood from that which is younger to that which is older, and sometimes
it becomes so broad that for an inch or more it will be filled with
bark. There may be some interruptions, where the bark disappears
to reappear after a few years.

I have not been able to find any tree showing "bird's-eye " until they
had acquired a diameter of about three inches or more, and then the
marks were very small. Such young trees have all been rather
crooked and knotty, with irregular swellings on the trunk compressed
in some places.

A smooth, straight, thrifty, healthy looking maple seldom shows the
"bird's-eye" to any extent.

The "bird's-eye " marks may be abundant and well marked on one
side or perhaps half or two-thirds of the circumference of the tree.
They may be well shown all around the lower part of a tree and partially disappear after a few feet above. "Bird's-eye " is rarely found
on the limbs of a tree, and seldom shown on the trunk above the
lower limbs.

Mixed with the bird's-eye" or more or less independent of it, will
often be found "blisters" and waves and curls of all conceivable
shapes. When such wood is split open, parallel with the bark, it of-
ten presents the appearance of folds of rich satin.

Where " bird's-eye" Maple is cut for market, most of the Maple trees
of the forest show somewhere, the peculiarity to a greater or less ex-
tent, but to be very valuable, this peculiarity should be abundant and
extend clear around the trunk, and should extend far enough up the
trunk to furnish logs of sufficient length to pay for marketing. These
logs should be destitute or nearly so, of deep pits containing bark or
bark streaks or shakes, and the thicker the sap wood the better, as the
dark colored or heart-wood is not saleable.

At Vanderbilt-in Otsego county, Mr. John Berry says the best trees
are found on the richest land with clay subsoil, where perhaps one
tree in twenty-five is marketable, while on thinner soil, the trees
are not so nice, and the proportion of marketable trees may be one
in forty.

No one can for certain select a good tree without peeling or cutting
out chips here and there, in several places on the tree, after cutting a
pole to lean against the trunk to enable a man to make examinations
at a height of ten or fifteen feet. The logs are finally cut in lengths
of two to eight feet, thoroughly steamed, placed in a secure position
to be turned over and over against a long knife which cuts off the
veneer.

I have found several other species of trees showing the "bird's-
eye" to a greater or less extent, usually only affecting the tree in a
slight degree, not sufficiently to be used as a veneer.

Notably among these, is the wood of the beech and more rarely,
the wood of hickory, white ash, black cherry, American elm, Nor-
way pine, red maple, silver maple, and probably many other species.

In some cases which I have seen, the depressions instead of being
circular, are narrow and lengthened, sometimes half an inch or more.
In some specimens of sugar maple and beech, these long narrow de-
pressions run up and down the tree; while in some observed in
sugar maple, they extend transversely around the tree across the
grain.

The wood of sugar maple, beech, white ash, and sometimes other
species is regularly curly, with the hollows and crests of the waves
well seen by splitting the stick parallel with the medullary rays or the
radius. These waves vary in length from three-eighths of an inch to
a foot or more from the crest of one wave to the crest of another.
In white ash and sugar maple and beech and rarely in black walnut,
and probably in other species, the waves occur irregularly on the
wood, parallel with the bark. Such wood is often used as a veneer,
and in case of white ash, it is spoken of as "calico-ash."

Instead of small pits in the wood as seen after removing the bark
of "bird's-eye" maple, the wood of several kinds of trees occasion-
ally contains more or less protuberances or cones, while in the bark,
there is a corresponding pit. These have been seen in the red maple,
sugar maple, hickory, American elm. In some cases, they appear to
have come from adventitious buds.

What causes "bird's-eye " in maple, beech or other woods?

The Indians of Northern Michigan have always attributed it to the
damage done the trees by the woodpeckers. I can give nothing in fact
to warrant such an opinion. Occasionally maples are pecked by these
birds, but such places do not become pits in the wood, as is the case
with " bird's-eye."

In case of the beech, sometimes, larvæ of an insect are found in the
inner bark extending to the cambium which they injure more or less.
Sometimes the insect kills a small spot of the cambium and a brown
spot on the wood and bark is the consequence. This dead spot is
sometimes enlarged in succeeding years by the action of more insects
and probably by the presence of fungi. In some instances the insect
seems to merely check the growth of the cambium in the spot
where it grows and a pit appears in the wood at this place. In
other cases, "birds-eye" beech seems to start without the aid of any
insect.

I have found no insects in the bark of the sugar maple which cause
the "birds-eye," yet when fresh living specimens are examined in the
summer, the cambium at the bottom of the pits appears to be more
or less injured showing minute spots of a yellowish brown color.