The Appeal. [volume] (Saint Paul, Minn. ;) 1889-19??, 1922-08-05
FINDS BATS TO
. BE MALARIA CURE
Erection of "Roosts" Around San
Antonio Made the LoWIands
HabitabIe.
Experimental FOR YEARS
Dr.. Charles A. r. CampbeIl's Discov-
cries and Scientific Work With
Bats Interests Naturalists
All Over World.

that completes with tuberculosis and
cancer in it's heavy toll of life, has
found it's Nemesis since science pro-
tects and shelters the bat as the nat
ural enemy of the malarial mosquito.
The result of DR.. Charles A. L.
Campbells discoveries and scientific
work with bats and mosquitoes has III
terested naturalists all over the world.
The first bat roost was built in San
Antonio for the purpose of Kidding
the city of the presidential. malarial
mosquito.
For years DR.. Campbell experiment
ed on bats to discover why they were
immune from the disease that wrought
such havoc with human beings.
Bats Abhor Jazz.
1t took a great many years for DR..
Campbell to be sure of the cause for
the difference in the susceptibility Of
the bat and that of other mammals.
w. D. Hornaday writes in the Los An
geles Times. The great difference in,
the anatomy Of the bat was found to
be in it's relatively much larger spleen:
1t is to this organ that DR.. Campbell
attributes the ability Of the bat to
thrive on the mosquito and consume
large numbers of them without Icing
affected.
In his experiments with bats Dr.
Campbell has come across several pc
culiar characteristics Of the animal.
For instance, bats abhor jazz. A
monograph, jazz record and a small
boy stationed on the top Of hunting
lodge infested with bats so startled
the animals in the early morning hours
as they returned to roost that they
flew some two miles away, entered an
other lodge and never returned to the
one in which they had been living for
two years. The explanation Of this is
that the ear Of the bat is so delicate
that discordant or strident noises are
to them the most Irritating of all SEN
sations.
The remarkable value of bats as
health service was demonstrated in
San Antonio when the malaria infected
swamp region around Lake Mitchell
where there was abundant grazing for
cattle was experimental on. 1t has
been said that formerly it was i'm
possible to build fences around this
land bordering the lake strong enough
to hold the cattle.
The myriads Of mosquitoes were not
only dangerous OH account of their
germ-carrying propensities, but their
bite was too painful even for beasts
having shoe-leather hides to endure
DR.. Campbell erected a bat roost On
rise in the neighborhood of the lake
and in year the place was cleared of
mosquitoes and thousands of bats had
taken their places. The grazing land
is now covered with fine, healthy cat
tie and the farm land is irrigated from
the waters Of the lake. Malaria is al
most unknown among the people dwell
ing in that locality.
It requires ten to fourteen days for
the malaria parasite to develop in
the blood of the mosquito after the
insect has been infected. With myri-
ad of bats flying about each night in
search of mosquitoes as food there is
little chance of mosquito living ten
days after it is old enough to fly
abroad at night. ..
Many Bat .Roosts in San Antonio.
After the success Of this campaign
against malaria bat roosts were estab-
!ished in the southwest outskirts of
San Antonio. This was so successful
in Kidding that portion of the city of
mosquitoes that the state erected an
other at the Southwestern Insane
asylum in San Antonio. Another was
erected at the West Texas Military
academy in Alamo Heights. Summer
homes and farms are now taking up
the idea.. -,
under DR.. Campbells supervision are
Of mammoth SIZE Often they rise to
height of thirty to fifty feet and are
fifteen to twenty feet square. The
largest of them accommodate from
100000 to 100000 bats, it is esti-
take their departure for the mosquito
hunting grounds they have the ap-
pearance of a dark cloud. Bats do not
range over wide territory in their
foraging expeditions, it is asserted.
Ordinarily they cannot be counted on
to cover a radius of more than three
miles and often they confine their
/ flights to a mile or less from their
roosting place.