Delaware tribune. [volume] (Wilmington, Del.) 1867-1877, 1874-10-08
Delaware Wribn,te
why Fruit DeoAys-An IatsFosstng sca.
oAsalAe Article 0a sAo subject.

why Fruit Deeays-An Iasercssing scs.
eaSaale Article oa sAe subject.
Our worst enemies, sAys the Scientific Amer.
can, arc the smallest. Ali the ravsnous beasts
In the world, mad dogs included, probably de-
stroy fewer human hves than are destroyed In
New York city alone BY the ravages Of those
minute but virulsnt organisms Of tho genus ni-
crooocoss to which VA owe smallpox, diptheria,
and some other malignant diseases. Similarly,
the thousand sturdy wseds which annoy the far
msr, the catssp liars and grasshoppsrs which 90.
casionally devour bis crops are relatively limo
cent and harmless compared with the numerous
microscopic pests which rust his grain, rot his
potatoes and fruit, and otherwise levy their bur
densone taxes without making themselves visi-
BILE.
Just at this season, not the least interesting
Of these individually Insignificant, collectively
enormous, nuisAncss are the two forms Of fun
gus growth which have most to do with the un-
timely destruction OF fruit-mncor mIcedo and
pendulum glaucun.
to, - Watts might say, but because it 10 the na-
ture OF something else to seize on them for sub
sistence, a. we do, Ut the same time making Of
them . habitat - we do not. Kept to them
selves, apples and other fruit never rot they
simply loose their juices by evaporation, shrivel,
remain substantially unchanged, ~ when secure
ly canned. II Ia only when invaded by the organ.
isms we have named that they loose color and
quality, take on offensive tastes and odors, be-
come covered with white or green mold-in short,
develop rottenness and decay.
It was not until the microscope WAS brought
TO bear that the real nature OF the process be-
came clear. Now We know that, 30 far from be.
ing the complement Of growth, the antithesis Of
life, decay is in reality the taking on Of more
rapid though specifically different grewth. tits
synonymous not with death, but with intensely
active life.
In general structure, the numerous, mrcro-
scopic fungi are very much alike, consisting
ments called the nycelium. This is the yege-
tative part. There Is, besides, = produc i've
part, in which is produced the seed or ''spore,"
the structure Of which is different in
tue ne, different different ag genera; In the muoor
ling at its superior extremity, in the interior of
which the spores are developed. In the pencil
lium glaucnm the reproductive filament bears q
tuft of from fonr to eight branches, which, in
turn, produce upon their extremities chaplet
on account Of this pencil-like tuft Of it's spore-
bearing iilaments, and gld,icum from their blush
green tint. The mold 80 frequently seen in
oranges is produced by this fungus. 1t is COM
paratiyey Of slow growth, and the alteration it
produces in the properties OF the fruit it lives in
and upon is not 10 marked a. that caused by the
mucor.
When the fruit invaded by either Of these fun.
gi,tie vegetativeii aments send their branches a.
mong aud around the fplit cells, and rapidly
envelope them III network Of mycelium, ab.
sorbing the substance and juice OF the fruit,
and producing the chemical transformation
characteristic of decay. All this goes on in the
interior of tho fruit, the fructifcation OF the
fungus taking place only on the surface, in con.
tact with the atmosphere. For this reason fruit
covered with firm, fine skin, like the apple,
may be mass OF what We call corruption within
in other words thoroughly decomposed by fun
gus growth-whle no visible nold-the fructi.
Tying part--appears on the surface On the 9TH
er hand; thin .sknned fruits like the strawberry,
which are easily pierced by the reproductive fl
aments, are often covered with an abundant
fructicatioi, in very short time, for the fe-
cundity of these microscopic cfungi is sometimes
as marvellous rs the rapidity of their
growth. For example single zoospore Of
the peronospord IN testdno which causes the po-
Ato rot, will envelop the cellular tissue of q po-
tato leaf with mycelium filaments in twelve
hours, and qualification will be completed in
eighteen hours longer. One square line Of the
under surface Of leaf, where the fructiicstion
naturally takes place, may bear as many M three
Thousand spores. Each spore supplies half a
dozen zoospores, individually capable Of origi
natlng a new mycelium. From one square line
therefore, there may GENE, in less than two
days, nearly twenty thousand reproductive
bodies, square inch may yield nearly three mil
Mons NO wonder the disease spreads rapidly
Inothe case of fruit, decay may be originated
in two ways and two only by direct contagior
or by wind waited spores. With tirm-skinnet
fruit like apples, still another condition is es
sential, namely, a break in the skin Of the frui
to allow the parasite to enter and take posses
son In every case Of decay in apples, the cen
ire OF disturbance will be found at bruise
scratch or puncture and unless such way b
opened, the apple may hang until it is dry a
leather, or it may lie for weeks in direct contac
with rottenness, and remain perfectly sound.
To this it may be objected that the constan
presence of the fungus in decay is no proof tina
it is the cause Of that condition, on the contrary
the breaking down of the fruit tissue by vic
lence, and rubsequent chemical action owing t
access OF hir,may rather make the growth Of til
fungus possible by preparing a suitable soil 70
its development, The objection has been met IL
tho Investigations Of Davaine. The eyidenc
that the fungus pr5c,des and causes the change
which We call decay is of the same character
that which establishes The connection between
vaccine pustule and incubation by vaccine virus
When sound fruit is inoculatsd with the spore
OF pendulum, decay begins at aud spreads fror
the point Of incubation Apples similarly wound
lied, but not inoculated, remain the same.