Morning journal and courier. [volume] (New Haven [Conn.]) 1848-1894, 1891-07-28
OUR SMALLEST SERVANTS.
Even the Bacteria are Necessary to
Man-An Living Organisms are De-
pendent Upon Each Other.
| Edward Strasshurper in Deuische Ruudschau,

Man-Au Living Organisms are De.
pendent Upon Each Other.
Edward Strassburger, in Deuische Ruudschau,
Berlin.1
To the Editor of the JOURNAL AND COURIER:
1 crave little space in your paper for
the insertion of the following which 1
doubt not will be of interest to many of
your subscribers who like myself, would
like to have word said for the bacteria of
which Old Sanitarian 80 eloquently speaks.
We are so much accustomed to regard
bacteria as the most dangerous foes of hui
manity that the attempt to demonstrate
their utility and essential Importance may
seem almost paradoxical. Nevertheless, it
would be as unjust to condemn the whole
class for the diseases engendered by a few
as to condemn humanity for the offenses
of it's criminals.
As matter of fact, the services of bac-
terra in the natural economy of the earth
are so important that disease germs may
fairly be regarded as isolated, scattered
| bands. The elimination of the bacteria
from the earth would be Immediately fol-
lowed bv our downfall. Refuse would
accumulate in piles mountains high, while
the plants which depend upon it for the
greater portion of their sustenance would
perish in sight of plenty, from the want
of microbes to convert it into assimilable
food. Every trace of organic matter is
greedlly seized on by microbes, which
convert it into plant food or decompose it
into its original elements, and thus render
the earth continuously habitable for man
and beast These bacteria are so small
that a million of them may constitute a
mass hardly visible to the naked eye,
nevertheless, such is their capacity for
increase, under favorable conditions, that
the progeny of single bacterium, if it
could multiply unchecked for fifteen days,
would constitute mass exceeding the
cubic contents of the ocean. Their in
crease is arrested only by failure of food
supply; they are consequently always in
sufficient numbers for the conversion of
all the dead inorganic matter of the earth
into food substance for living plants. The
manure which the farmer spreads on his
fields contains billions of these industriou US
laborers, all actively engaged in converting
the organic elements into plant food, and
even in rendering the inorganic substances
Qime, potash, phosphates, etc. assimilable
The most important soil constituents for
the farmers are the heterogeneous com
pounds, the presence of which in manure
constitutes its prime value as fertilizer
Plants cannot take nitrogen from the air
they must take it up by their roots from the
| soil. But nitrogen is not proper con-
| stituent of soils. In state of nature the
soil gets a supply from the substance of
| the plants and animals that die on it's
surface, but grain crops soon exhaust this
natural supply, and the fertility of the soil
can only be maintained by the addition of
| heterogeneous substance, which the bac terra,
| in pursuit of their own well-being, convert
| into assimilable plant food.
| But experience has taught the farmer
that while grain and root crops exhaust
the soil of its nitrogen, beans, peas and
other leguminous plants, SO far from ex-
hausting, add to its supply, thus render
ing possible high cultivation by rotation
of crops, with considerable economy of
manure. But these leguminous plants are
more capable than others of drawing their
heterogeneous supply from the atmosphere;
modern investigation has demonstrated
that it is the work of bacteria which finds
sustenance and habitation in the roots of
| the leguminous plants, where they multi
| ply from generation to generation, repay
| ing the service by dying there and sacri-
| fcing to the plant all the nitrogen they
have taken from the atmosphere, in assim-
liable form. The little swellings on the
| roots which constitute at once their dwell
| ing place, laboratory and tomb, may be
| readily recognized on removing an acacia,
| the pot in which it is grown.
Not less beneficial are the bacteria as
| purifiers of water. If vessel of water
| containing animal or vegetable refuse is
| allowed to stand in the open air the fluid
gradually clears until every particle of
| dead organic matter is consumed, when
| the bacteria cease their activity and sink
| to the bottom. The same thing occurs on
| the great scale in nature; the Seine, which
| at Paris receives an enormous amount of
refuse, is clear and pure at seventy kilo-
metres down stream. The bacteria have
consumed the refuse. The Elbe, the re-
| ceptacle of the refuse from so many cities,
| is drinkable at Hamburg from the same
| cause.
The relation of mutual interdependence
| subsisting between leguminous plants and
| the microbe guests of the roots, scientific
| ally characterized as "symbiotic" diving
| together) relation, exists between other
plants and microbes. A precisely similar
| relation exists between fungus and plants
growing in soil rich in humus, which con-
sequently require special treatment under
| cultivation. The heaths, rhododendrons,
| daphnes, etc., growing in such soils, sup
port thread fungus on their roots, which
reciprocates the service by supplying the
plants with nitrogen, and if the gardener
would cultivate them successfully. he
must import the soil as well as the plants
and be careful, moreover, not to allow the
soil to dry lest the fungi die.
The lichens and alga, insignificant and
lowly as they seem, play very important
role in the economy of nature. They sink
into insignifcance when the conditions are
favorable to the support of higher vegeta-
ton, but the task is theirs to create the
conditions necessary to the growth of high
er plants. Ascend the mountains, or pen
citrate into high ATTITUDES to the bound
| aries of eternal snow, and every rock is
found covered with lichens, the support of
the reindeer, and commonly but improper
ly called reindeer moss. With its slend-
er flaments it mines a foothold for itself
in the solid rock; the carbonic acid which
secretes, being dissolved in water, sets
free the silicic acid, and in this way de-
composes granite, gneiss, micaceous shale,
etc.
Its remains, in course of decomposition,
afford sustenance for moses, and in this
way the solid rock is decomposed into
plant supporting soil.
The imbauba tree (cecropia) of Brazil
exhibits an interesting instance of symbio-
sis between the tree and a species of small
black ant which subsists on it and keeps
watch and ward on every branch. The
leaf-cutting ant which inhabits this region
hoo q StlouS PaiIldllty lor luDauDd leaves,
and but for it's defenders would attack it
SO energetically that it would soon become
extinct; but woe to the leaf-cutting ant
that would essay to cut leaf of the i'm
bauba tree.
The examples selected are prominent in
stances of the absolute interdependence of
certain organisms, and suffice to suggest
the idea of common interdependence of
all living organisms. Each is dependent
upon the others for the qualification of its
needs. No one great section of life could
be eliminated without prejudice to the
rest. We ourselves could not exist but for
bacteria. The most pregnant examples are
those which come under the head Of SYM
biosis. But since the life of every living
organism on earth is more or less condi-
toned by the lives of all other organisms,
it is quite admissible from higher stand
point to regard all life on earth as single