The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1909-01-24

plasts (young cells) in such a way as to
form new kinds of plant growths called
gall structures. The parts affected
show an excessive growth (hypertro-
phy) due to a stimulus proceeding from
the parasite, because the plant forms
wall to protect itself against further
injury The fungus gall is thus COM
posed of corky cells, which the parasite
cannot injure. The simplest form of
fungus gall growth consists of few
degenerate spots indicating changed
cells in the center of large area of
plant tissue These resemble small
scars or warts. A gall called the AL
pine rose arises on a small rhododen-
dron of the Alps. It varies from the
size of a pea to that of a small apple,
and is yellow, but rosy-cheeked like a
ripe fruit. The leaves of the mountain
ash and of the garden pear tree some
times show conspicuous growths of a
reddish-yellow hue-forms resembling
tubercles with horns.
Laurels and blue pines often bear fun
gus gals on their stems. Cabbages and
the roots of the alder may exhibit gals
that involve the entire plant, those of
the alder being about the size of a wal
nut, with the roots twining around
them. Many fruit trees have their roots
dllCtttQ ny d UlSCdct
that is very contagious from irrigation,
and may ruin the entire orchard If the
diseased trees are not promptly re-
moved. The common juniper has nut
like gals from which project yellow
tongues consisting of masses of spores
fungus germs, seeds) imbedded in a
mucilage. Fruit trees and the silver
fir may show a uniform swelling all
around certain spots on branches, while
the larch shows a sunken and colored
spot from which rOsin flows; little cups
appear, red within and white outside;
the trees soon turn to a pale yellow
and then die. The curl disease of the
peach and almond is marked by over
growth and by brilliant celebration of
the leaves The pistils of the poplar.
plum and wild cherry may support
/ gals; and numerous other plants show
similar enlargements in various parts,
all due to the same causes.
II-eaIIs Produced by insects.
/ Most frequently gals are produced
by the attacks of certain insects which
| penetrate the tissues of plants and Law
/ their eggs therein. The insects mainly
/ responsible for the formation of these
exereseences are called gall mites, gall
gnats and gall flies or wasps. Calls
| thus produced are of three kinds: Felt
/ gals, mantle gals and solid gals The
| first consists of a layer added to the
/ surface of the plant; the second is a
/ hollow structure formed around the
/ part affected: the third an exeres-
cence produced by the piercing Of some
! spot and the Staying therein of an in-
/ sect egg. Later the larva will bore its
| way out of this snug winter home.
The Felt Calls.
Most felt gals are produced by gal
mites; they form cottony growths OF
parts of otherwise smooth leaves and
stems. The horse chestnut, grape, wal
nut, poplar, oak and aspen are specially
subject to these forms. Such gals art
usually brown in color; their hairy coy
erings were formerly supposed to be
fungus growths. but are now known
to be epideEmal cells grown in reactios
to the stimulus caused by the deposit oi
the eSgs Of mites in the plant tissue.
The Mantle Calls.
Mantle gals arc produced by insects
| that bore on the surface of the leaves
and attach their eggs to them. The
leaves show cavities in which the in
| sects live. They often form as scroll.
along one side of a leaf, as in this
cranesbiH. buckthorn and honeysuckle
| while plated gals occur on the curran
bush and the clematis. Globular anC
horn-like gals may occur on eims, aid
ers, naples and strawberry vines. Il
the covering gals. another kind of tbs
mantle type. the plant tissue grows
around the insect till the latter is com
| pletely rooted in. This occurs in the
ash, the singing nettie, the elm, tn,
poplar and in the Chinese nut gals q
commerce On the poplar leaf a pecu-
liar gall forms on the petrole; it ha: