The Yale expositor., 1914-11-26
CHANGES IN BACTERIA AND DIS
EASE.


ity, which is simply the power to re-
spond to stimuli, makes all organisms
the result of the interaction Of two
sets of factors-the factors of inheri-
lance and the factors of environment.
The factors of inheritance cover all
the complex association of properties
or capacities transmitted from the par
ents which make up the specific inheri-
lance characteristic of each individual;
the factor of environment on the other
hand covers all those conditions which
are capable of influencing the differ
entiation, growth and behavior, or, in
other words, the general metabolism,
of the organism. The inheritance may
be compared to everything that leads
up to the production of a blank
monograph disk; the environment
and stimuli may be compared to every
thing acting through the needle which
cuts the dots and dashes into the sur
face of the disk Obviously the final
result, or the individual, must be the
product of these two sets of factors
and In exact accordance with the quail
ity and capacity of the disk, the hard
ness or softness of the needle and the
amount of power behind it.
The same principle applies through
out the universe.
The continuation OF any type de-
ponds on maintaining all the factors
within certain scale; obviously, then,
II either of the sets OF factors be
altered the resulting organism will be
changed and what are known as varia-
tions will occur. These facts have en-
abled man to develop many useful and
valuable types of plant and animal.
Since the germs of disease are liv-
ing organisms they also must be sub
ject TO the laws of evolution, and in
this fact we have proof of the asser-
tion that every man makes his own
disease; because no two can be exact
ly alike, they must vary widely in
space and time. Not only does each
individual human being vary, but each
species of bacteria varies from time
to time, SO that the well-known dis
eases cannot be the same in different
localities or in different generations.
Proof OF this has recently been fur
nished in the work of Twort and Pen
fold, who have educated" the typhoid
fever bacillus to ferment sugar, which
ordinarily 1t does not do. Revis has
obtained varieties of the bacillus coli
structurally and physiologically differ
ent from the parent by prolonged cul-
ture in various media. Very recently
Madam Victor Henri has produced
marked mutations in a particularly
we'll defined and stable bacterial
species. the bacillus anthracis.
The micro-organism, bacterium an
thracis, gives rise to an infectious and
usually fatal bacterial disease in ami
mails, especially in cattle and sheep,
characterized by alterations Of the
skin, enlargement of the spleen and
general collapse, a disease generally
known as splenic fever. Man occa-
sionally contracts the disease by in
oculation from the animal. Carbuncle,
malignant pustule and wool sorteTs'
disease are caused by the anthrax bac-
terra. The normal bacterium is a long
rod shaped micro-organism having
marked and characteristic reactions.
Nine. Henri has modified the organism
with the ultraviolet light. The meth
cd employed was TO expose an aqueous
(water) suspension of anthrax spores
in a quartz tube to ultra violet radia-
tons for times varying from one to
forty minutes and afterward growing
cultures from these mixtures.
The majority Of the organisms were
killed by this treatment because the
ultraviolet rays were markedly bac-
tericidal, but a few survived and &C.
cording to the conditions and the
length of the exposure the bacillus I'M
derwent notifications and showed
characteristics decidedly different from
the typical anthrax bacillus. The
principal of these were a coccoid form
and a thin filamentous form. These
two forms constitute two new types
which Nine. Henri has isolated, and
they remain stable for about three
months. They produce anthrax which
has characteristics distinct from those
of the anthrax produced by the nor
NAL bacillus.
The normal anthrax microbe lique-
fies gelatin, curdles milk and takes
definite stains. The filamentous form
does not liquefy gelatin, curdle milk
or take the same stains, and it pro-
duces an infection different from the
anthrax on incubation. This form re-
mained absolutely fixed and stable aft
'er daily subculture for more than
eighty days; but though stable in the
incubator after passage through an
animal, coccoid forms taking a stain
similar to normal anthrax bacteria ap-
peared and, after subculture in broth,
a certain number Of bacillary forms
approximating the typical anthrax
we're obtained.
Inasmuch as all the above points
clearly to the fact that diseases are
only relative conditions. we should
rofrofv, fro,,.