, 1894-06-09

'i0A VII Y - - " NV C~ANN GPNO
nible red spots scattered about som If the
internodts, has been neutralised or absorbed,
and so far as external appearances 90, the
plant looks healthy, and is often supposed to
be so. But if, after the lapse Of a couple
Of months. say in September, q plant
which showed signs Of unllealthiness in the
previous May, be now taken and cut up
through the centre. it will. be seen that the
scarcely perceptible red ) ots that were re-
cOgnised in July, have now become compact
masses of mysilial deposit in tie centre of
white spots, which are surrounded by dark
red and cloudy oxygenised eferment, i'll the
first stage Of putridity. These whiAN spots
gradually become larger till they take up the
whole Of the internal portion Of the cane,
which varies from one sixteenth of an inoh
to one inch in depth. 1t is at this eruptive
phase of the disease that one or either, OF all
Of the three species of xylophaga or woodcut-
tiers, enter the cane, more, | believe, IN the
capacity of sanitary agents than malefaotors,
which combined conditions soon put an end to
the accretive functions Of the host plant, and
it dies from exhaustion.
OF the twelve species of fungi which vege-
tate ON the cane, six species prey upon the
sheath Of the blade, two species on the mid
rib Of the blade, one S%oecies on the parenchy-
ma of the blade, the other three species be-
ing found attached to injuries on the stem of
the cane. -Four out of the six species which
are parasi zeal on the sheath Of the blade are
the most destructive of the twelve species.
Their order Of antecedence and position on
the sheath of the blade not being constant,
] will cOnine my remarks to the species
which ] consider does the most injury. This
fungus is produced from what is technically
called a Sp0rangiam, or spore case, In which
is Secreted the spawn or vital matter from
which the species is propagated, and may be
named ASmodium intestans, and shortly de-
sclibed as follows-Sessile, pallid, slightly
granular, s%porangium spherical; the average
size of spOrangia one sixteenth OF al inch IN
greatest diameter, terminating by minute
buds or beads Of mysilial spawn, which exude
from the sides in the form Of transparent, al
most invisible threads, which get attached to
the sheath Of the blade, as the sheath comes
up through the soil to the level of the surface.
In four or five days after the mysilia have be-
come attached to the sheath Of the host plant,
they have penetrated and passed through the
cellular tissue to the inside of the sheath;
then they spread up through the parenchyma
to the extent of from six to ten inches, mean
while penetrating inwards and passing
through the sheaths of all the inner blades
till they ultimately reach the stem Of the
cane. Having developed their energy thus
far, they now m to weave a thick web
of white mysilia felt, from which is produced .
81 considerable crop Of globular fruit or seeds.
which are easily recognized on both the out
and inside of the affected sheath. In about
eight or ten days the fruit falls to the ground.
where it remains, il not disturbed, in a qul'
escent state for a couple Of months; again to
come forth and glut it's Unsuitable and aCrid
appetite.
When the cells of vascular bundles and
cellular tissue Of a sheath that is affected by
the above fungus, are examined, 1t is found
that they are ~ruptured and otherwise disor-
ganiSed and have become mechanically unfit
to perform their a~ccretive functions either
In forming or in distributing the carbohydrates
in a condition essential to the healthy matur-
ing Of the plant, hence the cause Of the in
creased ravaees of the moth larval bOrers,
not from an undue increase of these insects,
but solely on account of the nutritlve quality
of their food having become so poor they
have to consume a greater quantity of mate
rial in a cane that has been affected by fungi
than they nave to do IN a sound cane. This
defect in the nutritive quality of cane affected
by fungi parasites, appears to arise from a
disorganised association Of it's ternaTy con-
s%tituents with their mineral equivalents in
the process of assimilation, and not to a de-
terioration of accretive energy in a p~artlcu-
-. o,iot &c ann NIootc 70 mhInh MANY