Evening star., 1911-01-22

cause, this possibility. say the patholo-
gists, should be investigated A leak Oh
any considerable size kills quickly, OFTEN
in a few hours, but small leak may re-
suit simply in an unhealthy condition OF
a single tree or the death of only part
of it. Even the expert may be deceived
in such cases.
The symptoms of gas poisoning in fatal
cases. it is explained, are fairly cnar-
acteristic. but difficult to describe. The
first effect is yellowing and whiting of the
foliage, with partial or complete defolia-
ton. The sapwood is usually discolored.
and if the injury occurs in the CROWNS
season it has Very marked ana char-
acteristic odor.
Trees are subject to mysterious epidem-
ic diseases as well, or as badly, as human
beings. -,
"Thus." said Mr.. Metcalf. during the
summer of 1907 many trees. especially
NAPLES, were affected with an apparent
disease Of the leaves. in which the syinp,
toms ranged from partially Dleacheu
spots in the leaf to dead tips and edges
or even completely dead leaves and con-
seuuent defoliation. Such leaves were II
yariably found to be gored with staISn.
While there can be little doubt that TINS
trouble finds its explanation in the pc
culiarities of weather and water supply
of the season in which it occurs. II Is ps
no means to be attributed to more SIM
ME conditions producing somewhat SIM
lar results, but Is H1OTe piODoDis -
mite physiological disease
X x
II has been remarked by one OF the
forest enthusiastically inchneo u
tho ns,rrv uuip and quaint jest Wlthai-
that although a tree with a cold hasn
eot cough it may have bad bark
ubich reveals the injury. However, al
+houpb the diseased condition of the tls-
smes of a tree fatally injured by the WIN
tr,y blasts may be manifested, as soon as
they have thawed. by exterior inuicatiois,
in MANY cases the winter kilnng does not
become evident until the vigorous CIV y,
IF early summer begins. tree afflicted
with one form of cold has the water
talxen ont Of it's tissues and changed TOT
tho time into ice If the tissues are un-
able to take water again they necessarily
die. -,
under certain conditions are liable re-
sembles the grip. in that 1t may pave the
way for other disease. Many trees, espe-
cially smooth-barked ones. have their
trunks and larger branches injured on
the southwest side by the freezing and
consequent death of patches of bark.
During the warmer days of winter there
is sufficient heat at noon to stimulate por-
tions of the growing layer INTO prema-
ture growth, which tissue Is killed II cold
does not become manifest until we'll into
the summer. The diseased Tissue forms a
favorable place for the growth OF certain
organisms, and such tree usually dies
in few years.
X i,
There is a winter disease from which
trees in certain sections are likely to
suffer and which the government tree
doctors are only now beginning to dis
tinguish from tree grip. il the term be
allowable. This affection is accompanied
by drying out of the tissues. and occurs
principally In the higher attitudes OF the
west, where the dry and rarefied air
and bright sun favor evaporation from
the tree surface of more water than the
roots can obtain from the cold and fire.
quently sandy or gravelly soil Thus
prevailing principally in the regions men-
toned. the disease, 1t is said, is liable
to occur anywhere. Evergreens are es-
fpecially subject to this trouble, since their
leaves last to some extent throughout
THE winter. This diseasej is readily