The Portland daily press., 1897-11-20
ANTS AND FLIES.
A Naturalist Proves How They Distribute
Xeasts and Molds.

The part played by insects in the dis
tribution of minute vegetable organism
has been made the subject Of an inter
esting lnve sigation by Dr. Amedeo Ber-
| lese at the Portici Laboratory for Agri-
cultural Chemistry. That they do per-
| form this task, often very mischtevous
one, has long been known, but the pro-
fessor, as is shown in the current number
of Nature, has proved that, for good or
evil, they are more active than had been
hitherto asoertained. Ants were the SUBJ
jects of his arst experiments. He had
frequently detected the cells of two alco-
holic yeasts hidden in fssuTes of the bark
ON the trunks of both fruit and forest
trees. These he suspected to have been
transported by the ants, which were con-
stantly travelling up and down the
trunks, and it seemed likely that flies
might cooperate in the work First. he
''put the question" to the ants He COL
lected large number OF a species which
is very common in vineyards They
were allowed access to punches of cranes
which had been carefully sterilized. and
afterward placed under conditions that
prevented the possibility of any introduo.
tion of molds or yeasts from the outer air
The result in less than fortnight. was
that all the bunohes which the ants couid
Wis were abundantly infested with
yeasts and lnolds, while several Others
which had been preserved, even for a
much longer time, in sterilized yassele
from which the ants were exoluded
had neither molds nor yeasts nor bacteria
on their surfaces.
H. ~
Dr. Berlese then turned his attention
to the lies. His methods of inouisition.
we fear, would not be approved by those
who share Corporal Toby's view and are
merclful even to the housefiy and the
bluebottle. In fact, these. torments of the
human race must have had y decidellv
bad time in the laboratory. The fist ex
pertinent, however, was simple and
humane. A number Of bits of steriIized
meat were seU kouG on terrace. some of
them covefe6 by wire gauze, others acces-
sible to the flies. After two hours' exnos-
ure to them and thirteen to the air. veasts
were found to be much more abundant in
the former; indeed DR. Berlesa estimates
that the quantity of yeasts convened by
lilies is about twenty-six times as great as
Is brought by the air. Similar expert
ments were made with grapes, and with
similar results. The next point to settle
was the precise way in which the trans
port ws s effected. 1t was first ascertained
that ferments We're often more frequent
In the bodies of flies than on their legsf
and feet; next, cells similar TO those O
yeast were detected in their excreta. It
remained then, to study the passage of
these cells through the digestive appara-
tus of the insect. Common blue BOTTLES.
OF meat files, were selected for this pur-
pose, and large number of experiments
were made on them; but some other flies
and cellar midges were also tested.
1t was proved in all cases that when
the tiles were fed with sterilized materia.
the exoreta contained no yeasts; but
when they had diet of pure cultures Of
sundry yeasts the excreta soon contained
in great quantities the yeasts that were
in the food. These cells also were not
dead, but living. If collected, they duly
germinated and developed, though the
rate OF the process and the abundance of
the result were found to depend to a con-
siderable extent on the temperature
maintained. Further experiments indi.
Gated that the cells increased in number
in passing through the body of the fly,
and the general result of the whole series
was to demonstrate that ants and certain
flies play an important part not only in
the distribution (as was already known),
but also in the reservation of and multi
plication of alcoholic ferments Insects.
in fact, contribute far more than atmos-
pheric air to the dissemination of yeasts.
which aresconveyed internally rather than
externally. In some cases this distribute.
ing agency may be exercised for good.
but we suspect it is far more often potent
for evil.-London Standard.