The times. [volume] (Washington [D.C.]) 1897-1901, 1901-04-13
INSECTS AND DISEASES.
DIR. WnrdeII ytf&s TeII- of the Dis
seminat;on ~ Germs,

DIR. wnrdeII Stif&s fell. of the Dis
semination OF Germs.
The second of the new series of Toner
lectures. given under the auspices of the
| School of Medicine Of Georgetown Uni
versity. was delivered before a large au-
dience by Prof. CHI Wartlell Stiles, a. NJ,
FIJI. D.. at Georgetown College last night
| His subject of discussion was Insects as
Ipsseminators of Dfseae." and by means
OF number of fine lantern slides the
lecture was made particularly Interesting
DIR. Stiles said in the course of his lee
ture:
1T is sometimes charged that scientists
make public too many facts concerning
microbes. and that at the present rate
the laity will soon either become dis
Susted with hygienic research or will come
to the belief that death turks in every
thing we eat drink. touch. or breathe.
That wild hygienic theories and specula-
lions have at times been launched upon
the public cannot be denied, and some
men have undoubtedly laid themselves
open to censure by rushing into print
with uniustified conclusions based upon
scientific dreams. Let us recall. how
ever, that until the cause and method of
dissemination of a given disease are
known, the hygienist. whose duty it is to
guard against that malady, must take
into consideration all imaginable possibili-
ties. When, on the other hand, the cause
and source are once matters of positive
knowledge, effort may he intelligently con-
centrated and the preventive measures
given definite direction.
insects must be looked upon as among
our best friends and worst enemies. Some
insects are instrumental in the spread
of the pollen by which certain plants are
fortified, and they are thus important
factors not only in identifying our sur
roundngs. but also in the economics of
the country. Destroy all of the bees and
you will destroy one OF the important
forage plants namely, clover. Other In
sects are injurious to plants or animals.
1t is estimated. for instance, that certain
flies cause an annual loss of about $50
100000 to the cattle industry of the United
States.
Other insects are active In the dissent
nation of disease germs. A certain mos
quito in Italy is the normal carrier of
malady which causes that country 15,OO0
deaths and about 100000 cases of disease
per year When we consider the aggre-
gate human suffering involved and the
economic loss brought about by this mos
quito, our imagination is almost stag
gered. Assume, for instance, that these
100000 patients average loss of 81
surely very low estimate-in time taken
from work, in doctor bills, in drugs, fu-
neral expenses, etc, and We obtain the
total Of s3,O10.000, in addition to the pain
endured and the economic loss through
death
THE insects which come more especial
ly into consideration in connection with
the diseases of man are mosquitoes, flies,
and fieas. and when we turn to the dis
cases of animals we must add to this list
the ticks and crustaceans, two groups of
aTthropods closely related to insects"
DR.. Stiles distinguished between two
general classes of diseases-first, those
which must necessarily. be transmitted by
insects, and secondly, those in which in
seets are only accidental though In many
DIR. Stiles continued, rs normally trans
mittcd by mosquitoes. and is dependent
upon them. XIII eli mosquitoes and ma
3r viii Disappear typhoid fever on on
flies. yet it's spread is not wholly due to
them. Kill OFF alt tiies Iand you win I'M
doubleday decrease typhoid. but since In
sacts are only accidental and not neces-
sary spreaders of this nal-dy, such meas
ures Will not eradicate 1t.
We may Law down tw1o general biologic
rules, which believe are enunciated to-
night for the first time The first rule, to
which at present q few exceptions are
known. is that diseases which are acct
dentally spread by Insects are caused by
parasitic plants. particularly Dy bacteria.
The second rule to which no exceptions
are as yet known IS that those diseases
which are dependent upon insects or
other arthropods for their dissemination
are caused by parasitic animals. particu-
larry by sporozoa and worms
Concluding his interesting lecture DR..
Stiles said: Not every germ is danger
Gus and not every insect disseminates dis
ease. Many germs and many insects are
positively useful to us. The dangerous
germs and the insects which transmit
them should. however. be guarded against
and destroyed, and although the Wash
inston Humane Society in placing itself on
record as opposing the protection of life
and property by the dehorning of cattle
we may confidently hope that active and
well intending body of esteemed fellow
citizens will still permit us to kill mos
quitoes. flies. fieas. and bedbugs. not only
IN order to increase our comfort. but in
nrder give human life ~