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5, DEPARTMENT OF AGRICULTURE,

BUREAU OF ENTOMOLOGY BULLETIN Uo. 78.

L. O. HOWARD, I ni.wnoloBi»t and Chief of Bureau

ECONOMIC LOSS TO THE PEOPLE OF THE

IXITED STATES THROUGH INSECTS

THAT CARRY DISEASE.

l'.Y

L, O. HOWARD, Ph. D.

Entomologist and Chief of Bureau.

Issued March 18, 1909.

* MAR20mq

WASHINGTON:

GOVERNMENT PRINTING OFFICE
1909.

U.S. DEPARTMENT OF AGRICULTURE

BUREAU OF ENTOMOLOGY BULLETIN No. 78.

L. O. HOWARD. Entomologul and < 3uef ol Bureau.

ECONOMIC LOSS TO THE PEOPLE OF THE

UNITED STATES THROUGH INSECTS

THAT CARRY DISEASE.

BY

L. O. HOWARD, Ph. D.

Entomologist and Chief of Bureau.

Issued March 18, 1909.

WASHINGTON:

GOVERNMENT PRINTING OFFICE

1 909,

BUREAU OF ENTOMOLOGY.

L. O. Howaed, Entomologist and Chief of Bureau

C. L. Mablatt, Entomologist and Acting Chief in aosena of chief.

R. S. Clifton, Chief Clerk.

F. H. Chittenden, in charge of truck crop and special insect investigations.

A. D. Hopkins, in charge of forest insect investigations.

W. D. Hunter, in charge of southern field crop insect and tick investigations.

F. M. Webster, in charge of cereal and forage plant insect investigations.
A. L. Quaintance, in charge of deciduous fruit insect investigations.

E. F. Phillips, in charge of apiculture.

D. M. Rogers, in charge of gipsy moth and orown-tail moth work.
A. W. Morrill, engaged in white fly investigations.
W. F. Fiske, in charge of gipsy moth laboratory.

F. C. Bishopp, engaged in cattle tide life history investigations.
A. C. Morgan, engaged in tobacco insect investigations.

R. S. Wogltjm, engaged in hydrocyanic-acid gas investigations.
R. P. Currie, assistant in charge of editorial work.
Mabel Colcord, librarian.
2

LETTER OF TRANSMITTAL.

U. 8. Department of Agriculture,

Bureau of Entomology,
Washington, D. C, January 15, 1909.
Sir: I have the honor to recommend for publication as Bulletin 78
of this Bureau the accompanying manuscript entitled "Economic Loss
to the People of the United States Through Insects that Carry
Disease."

The United States is just awakening to a knowledge of the disas-
trous results following a lack of appreciation of the danger arising
from the unchecked development of mosquitoes and the typhoid fly,
and it is hoped that this bulletin will not only emphasize this danger,
but will also lend support to movements, both local and widespread,
toward the destruction (often so easy) of these carriers of disease.
Kespect fully,

L. O. Howard,
Entomologist and Chief of Bureau.
Hon. James Wilson,

Secretary of Agriculture.

CONTENTS

Page.

Introduction 7

Mosquitoes 8

Malaria 8

Yellow fever 17

Work on the Isthmus of Panama 21

The typhoid fly. commonly known as the house fly l'.*;

Endemic disease as affecting the progress of nations :;t;

Index 39

5

ECONOMIC Loss TO THE PEOPLE OF THE UNITED STATES
THROUGH INSECTS THAT CARRY DISEASE.

INTRODUCTION.

It has been definitely proven and is now generally accepted thai
malaria in its different forms is disseminated among the individuals
of the human species by tin' mosquitoes of the genus Anopheles, and
that the malarial organism gains entrance to the human system, so
far as known, only by the bite of mosquitoes of this genus. It has
been proven with equal definiteness and has also become generally
accepted that yellow fever is disseminated by the bite of a mosquito
known as Stegomyia calopus (possibly by the bites of other mos-
quitoes of the same genus), and. so far as has been discovered, this
disease is disseminated only in this way. Further, it has been sci-
entifically demonstrated that the common house II v is an active agenl
in the dissemination of typhoid fever. Asiatic cholera, and other
intestinal diseases by carrying the causative organisms of these dis-
eases from the excreta of patients to the food supply of healthy indi-
viduals; and that certain specie- of (lea- are the active agents in the
conveyance of bubonic plague. Moreover, the tropical disease known
a- filariasis is transmitted by a species of mosquito. Furthermore, it
is known that the so-called "spotted fever" of the northern Rocky
Mountain region is carried by a species of tick; and it has been dem-
onstrated that certain blood diseases may be carried by several species
of biting insects. The purulent ophthalmia of the Nile basin is
carried by the house fly. A .similar disease on the Fiji Eslands is
conveyed by the same insect. Pink eye in the southern United State-
is carried by minute flies of the genus Hippelates. The house fly
has been shown to be a minor factor in the spread of tuberculosis.
The bedbug ha- been connected with the dissemination of several dis-
eases. Certain biting (lie- carry the sleeping sickness in Africa. A
number of dangerous diseases of domestic animal- are conveyed by
insects. The literature of the whole subject ha- grown enormously
during the pasl few year-, and the economic loss to the human species
through these insects is tremendous. At the same time, this loss is
entirely unnecessary; the diseases in question can be controlled, and
the suppression of the conveying insects, so absolutely vdtal with
certain of these diseases and so important in the other-, can be brought
about.

7

8 LOSS THROUGH INSECTS THAT CARRY DISEASE.

MOSQUITOES.

Entirely aside from the loss occasioned by mosquitoes as carriers
of specific diseases, their abundance brings about a great monetary
loss in other way-.

Possibly the greatest of these losses is in the reduced value of real
estate in mosquito-infested regions, since these insects ivn.hu- abso-
lutely uninhabitable large area- of land available for suburban home-.
for summer resorts, for manufacturing purposes, and for agricultural
pursuits. The money loss becomes most apparent in the vicinity of
large centers of population. The mosquito-breeding areas in the
vicinity of New York City, for example, have prevented the growth
of paying industries of various kind- and have hindered the proper
development of large regions to an amount which it i- difficult to
estimate in dollar- and cent- and which is almo>t inconceivable. The
same may he said for other large cities near the seacoast. and even
of those inland in low-lying regions. The development of the whole
State of Xew Jersey has been held hack by the mosquito plague.

Agricultural regions have suffered from this cause. In portion- of
the Northwestern States it has been necessary to cover the work horses
in the field with sheets during the day. In the Gulf region of Texas
at times the market value of live stock is greatly reduced by the
abundance of these insects. In portions of southern Xew Jersey there
are lands eminently adapted to the dairying industry, and the markets
of Xew York. Philadelphia, and the large Xew Jersey cities are at
hand. In these localities herds of cattle have been repeatedly estab-
lished, but the attack- by swarms of mosquitoes have reduced the yield
of milk to such an extent as to make the animals unprofitable, and
dairying has been abandoned for less remunerative occupations. The
condition of the thoroughbred race horse- at the great racing center,
Sheepshead Bay. Long Island, was so impaired by the attack- of
mosquitoes as to induce those interested to spend many thousands of
dollars a few year- ago in an effort to abate the pest.

All over the United States, for these insects, and for the house fly
as well, it has become necessary at great expense to screen habitations.
The cost of screening alone must surely exceed ten million- of dol-
lars per annum.

MALARIA.

The west coast of Africa, portions of India, and many other tropi-
cal regions have always, at least down to the present period, been
practically uninhabitable by civilized man. owing to the presence
of pernicious malaria. The industrial and agricultural development
of Italy ha- been hindered to an incalculable degree by the prevalence
ol malaria in the southern half of the Italian peninsula, as well as in

MOSQUITOES A.ND MALARIA. 9

the valley of the Po and elsewhere. The introduction and spread of
malaria in Greece is stated by Ronald Ross, and with strong reasons,
to have been largely responsible for the progressive physica] degen-
eration of one of the strongest rare- of the earth.

In the CJhited State-, malaria, if not endemic, was early introduced.
The probabilities arc that it was endemic, and it is supposed that the
cause of the failure of the early colonic- in Virginia was due t<> this
disease. It is certain that malaria retarded in a marked degree the
advance of civilization over the North American Continent, and
particularly was this the case in the march of the pioneers through-
out the Middle A\\^t and throughout the Gulf States west to the Mis
sissippi and beyond. In many large regions once malarious the disease
has lessened greatly in frequency and virulence owing to the reclama-
tion of swamp areas and the lessening of the number of the possible
breeding places of the malarial mosquitoes, but the disease is Mill
enormously prevalent, particularly so in the southern United State-.
There are many communities and many regions in the North where
malaria is unknown, but in many of these localities and throughout
many of these regions Anopheles mosquitoes breed, and the absence
of malaria means simply that malarial patients have not entered these
regions at the proper time of the 3rear to produce a spread of the
malady. It has happened again and again that in communities where
malaria was previously unknown it has suddenly made its appearance
and spread in a startling manner. These cases are to be explained,
a- happened in Brookline, Mass., by the introduction of Italian labor-
ers, some of whom were malarious, to work upon the reservoir; or.
a- happened at a fashionable summer resort near New York City, by
the appearance of a coachman who had had malaria elsewhere and
had relapsed at this place. In such ways, with a rapidly increasing
population, malaria is still spreading in this country.

To attempt an estimate of the economic loss from the prevalence
of malaria in the United States is to attempt a most difficult task.
Prof. Irvine; Fisher, in one of his papers before the recent Inter-
national Tuberculosis Congress, declared that tuberculosis costs the
people of the United Stale- more than a billion dollars each year.
In this estimate Professor Fisher considered the death rate for con-
sumption, the loss of the earning capacity of the patients, the period
of invalidism, and the amount of money expended in the care of the
sick, together with other factors. In making these estimates he had
a much more definite basis than can he gained for malaria. The
death rate from malaria (as malaria) is comparatively -mall and is
apparently decreasing. Exact figures for the whole country are not
available. From a table comprising 22 cities it appears that two-
thirds of the deaths from malaria in the United Slates occur in the
South — one-third only in the North. The death rate from malaria
70951— Bull. 78—09 2

10

CHBOUGB [NSECTS THAT CABBY DISEASE.

by States is available only for the following registration States:

California. Colorado. Connecticut, District of Columbia, Indiana.
Maine, .Maryland. Massachusetts, Michigan, New Hampshire, New
Jersey, New York, Pennsylvania, Rhode Island. South Dakota, and
Vermont, all of which arc Northern State-. For these State- the
census report- from L900 to L907, inclusive, give the following death
rates :

Tabu I. -Deaths dm to malaria in the registration States, 1900-1907.

Year.

Number
of deaths
from ma-
laria per
100.000
popula-
tion.

Total
deaths
from ma-
laria.

Year.

Number
of deaths
from ma-
laria per
100,000
popula-
tion.

Total
deaths

from ma-
laria.

1900

7.9
6.3
5.4
4.3

4.2

2, 434
1,791

1,738
1,410
1,391

1905

3.9

] 3>1

1901

3.5

1902

1 1907

l Ififi

1903

1904

Estimating, from the preceding table, the average annual death
rate due to malaria at 4.8 per 100,000 population, and considering
that the registration area includes only 1G of the Northern States
I assuming fairly, however, that the death rate in the other Northern
States is the same) , it seems reasonably safe to conclude that the death
rate from malaria for the whole United States must surely amount
to 15 per 100,000. It is probably greater than this, since the statistics
from the South are city statistic-, and malaria i- really a country
disease. Thus it is undoubtedly safe to a— nine that the death rate
for the whole population of the United States is in the neighborhood
of 15 per 100,000. This would give an annual death rate from
malaria of nearly 12,000 and a total number of deaths for the 8-year
period 1900-1907 of approximately 96,000.

But with malaria perhaps a- with no other disease doe- the death
rate fail to indicate the real los> from the economic point of view. A
man may suffer from malaria throughout the greater part of hi- life,
and his productive capacity may be reduced from 50 to 75 per cent,
and yet ultimately he may die from some entirely different immediate
cause. In fact, the predisposition to death from other causes brought
about by malaria is so marked that if. in the collection of vital statis-
tics, it were possible to ascribe the real influence upon mortality that
malaria possesses, ihi- disease would have a very high rank in mor-
tality tables. Writing of tropical countries, Sir Patrick .Man-on
declare- that malaria causes more deaths, and more predisposition to
death by inducing cachectic states predisposing to other affections,
than all the other parasites affecting mankind together. Moreover,
it has been shown that the average life of the worker in malarious

MOSQUITOES \.\i> m \i.\i;ia. 1 1

place- is shorter and the infant mortality higher than in healthy
place-.

But, aside Prom this vitally important aspect of the subject, the
effect of malaria in Lessening or destroying the productive capacity
of the individual is obviously of the utmost importance, and upon the
population of a malarious region is enormous, even under modern
conditions and in the United State-. It has been suggested thai the
depopulation of the once thickly settled Roman Campagna was due to
the sudden introduction of malaria by the mercenaries of Scylla and
Marin-. Celli, in L900, states thai owing to malaria about 5,000,000
acres of land in Italy remain — not uncultivated, but certainly very
imperfectly cultivated. Then also, in further example, in quite recent
years malaria entered and devastated the islands of Mauritius and
Reunion, practically destroying for a time the productiveness of these
rich colonies of Great Britain and France.

Creighton, in his article on malaria in the Encyclopaedia Britannica,
states that this disease ** has been estimated to produce one-half of the
entire mortality of the human race; and inasmuch as it is the most
frequent cause of sickness and death in those parts of the globe that
are mo-t densely populated, the estimate may be taken as at least
rhetorically correct."0

Is it possible to make any close estimate of the ratio between the
number of deaths from malaria and the number of eases of the same
malady? No perfectly sound basis for such an estimate is apparent.
In the English translation of Celli's work on " .Malaria According
to the New l^'searches,'' published in London in 1900, it is stated
that the mortality from malaria in Italy from 1887 to 1898 varied
from 21,033 in the first-named year to 11,378 in the last-named year,
and the mean mortality for the period is assumed to be about 15.000.
In 1896 a count of the patients in the hospitals in Rome was made,
and the mortality rate of 7.75 per thousand of the actual patients was
established. Calculating then on this basis, and at this rate, the num-
ber of cases per year for Italy was placed at about i\000,000. Accord-
ing to this estimate, and with the average mortality for the United
State- of 12,000 as above indicated, the approximate number of
cases for the Onited State- would be about 1.550,000. It seems obvi-
ous, however, that Celli. in using the ba>is of hospital patients only,
must have underestimated the number of cases for the Kingdom,
since of the people in the country suffering from malaria the propor-
tion entering the hospital must be relatively -mail. Therefore the
death rate from malaria of malarial patients in the hospital must be
greater than the death rate from malaria of the- people who suffer
from this disease in the whole country. In fact, so great must this

u See "Darwinism and Malaria," by It. a. Eccles, M. D., Medical Record,
New York, January m. L909, pp. 85-93.

12 Less THROUGH [NSECTS THAT CARET? DISEASE.

discrepancy necessarily be that it would not -win at all unlikely to
the writer if the number of persons suffering from malaria in Italy
weiv in reality nearer 3,000,000 than 2,000,000.

'Flic same argument will hold for the United States, and more
especially so since a- a rule malaria in this country is of a lighter
type than in Italy: in fact an estimate of -'UJOO.OOO cases of malaria
in the United States annually i- probably by no mean- too high. It
will not be an exaggeration to estimate that one-fourth of the produc-
tive capacity of an individual suffering with an average case of ma-
laria is Lost. Accepting this a- a basis, and including the loss through
death, the cost of medicine-, the losses to enterprises in malarious
regions through the difficulty of securing competent labor, and other
factors, it is safe to place the annual loss to the United State> from
malarial disease under present conditions at not le^s than one hundred
millions of dollars. Celli has shown that in Italy the great railway
industries, for example, feel the effect of malaria greatly. Accord-
ing to accurate calculations one company alone, for 1,400 kilometers
of railway and for 6,416 workmen in malarious zones, spends on ac-
count of malaria 1,050,000 francs a year. The same writer states that
the army in Italy from 1877 to 1897 had more than 300,000 cases of
malaria.

The loss to this country in the way of retardation of the develop-
ment of certain regions, owing to the presence of malaria, i- extremely
great. Certain territory containing most fertile soil and capable of
the highest agricultural productiveness is practically abandoned.
With the introduction of proper drainage measures and antimosquito
work of other character, millions of acres of untold capacity could
be released from the scourge at a comparatively slight expenditure.
These regions in the absence of malaria would have added millions
upon millions to the wealth of the country. Drainage measures are
now being initiated by the United States. Parties of engineer- are
being sent by the Government to make preliminary drainage sur-
veys in the most prominent of these potentially productive regions.
The following statement concerning the effect of malaria on the
progress of this work has been made to the writer by Dr. George Otis
Smith, director of the United State- Geological Survey:

" In one of the Southern State- 1 1 topographic parties have been at
work during the past field season. The full quota for these panic-
would be 55 men. but I believe that something over 100 men have
been employed at different times during the season. While I have
not exact figure- before me, I feel warranted in the statement that at
least 95 per cent of these employee- have been sick, for periods rang-
ing from a few days up to two weeks, in the hospital. Many of them
have been able later to return to work, but at leas! 30 per cent had
to leave the field permanently. Bv reason of this sickness the effi-

MOSCJ i - and MALARIA. 1 .",

ciency of the parties was reduced, at a very conservative estimate, l>\
25 per cent.

•• In ii i \ recent visit in this field I found one man sick in each <>f
Lhe parties I saw and one man who had just returned from the
hospital leaving the field for good. A similar state <d" things was
reported from the other parties. I regard the sickness as practically
all of a malarial nature, as extreme care was taken in all the camps
to use nothing but boiled water except in a few instances where arte-
sian water from ureal depths was available. In all the camps the
tents have been screened, and in every case where the topographer has
lived for any time "on the country' there has been infection. As
illustrating the value of the precautions generally taken by our camp
parties, I might cite the fact that last year in West Virginia with 30
men living in camp, with typhoid fever prevalent in the neighborhood.
no cases developed, while with 6 men living on the country where
the same care could not be taken regarding the water supply, two
cases of typhoid developed."

In estimating the weight of Doctor Smith's statement, it must he
borne in mind that the men of his held parties are exceptionally in-
telligent and prepared to take all ordinary precautions.

Throughout the region in question malaria is practically universal.
The railroads Miller, and at the stations throughout the territory it is
practically impossible to keep operators steadily at work. This re-
duction in efficiency in the surveying parties and in the local railroad
officials is moreover probably very considerably less than the reduc-
tion in the earning capacity of the entire population, which, however,
i^ necessarily scanty.

In an excellent paper entitled " The relation of malaria to agricul-
tural and other industries of the South," published in the Popular
Science Monthly for April, 1903, Prof. Glenn W. Herrick, then of
the College of Agriculture of Mississippi, after a consideration of
the whole field, concludes that malaria is responsible for more sick-
ness among the white population of the South than any disease to
which it is now subject. The folloAving forcible statement referring
to the States of Loui.-iana. Mississippi, Alabama. Georgia, and South
Carolina is in Professor Herrick's word-:

" We must now consider briefly what 635,000 or a million cases of
chill- and fever- in one year mean. It is a self-evident truth that it
mean- well for the physician. But for laboring men it means an
immense loss of their time together with the doctor^' fee- in many
instances. If members of their families other than themselves be
affected, it may also mean a loss of time together with the doctors'
fee-. For the employer it mean- the loss of labor at a time perhaps
when it would be of greatest value. It it doe-, not mean the actual
loss of labor to the employer it will mean a loss in the efficiency of

14 Loss THBOUGB INSECTS THAT CARRY DISEASE.

Iris labor. To the fanner- it may mean the loss of their crops by
want of cultivation. It will always mean the noncultivation or

imperfect cultivation of thousands of acre- of valuable land. It
mean- a listless activity in the world's work that count- mightily
againsl the wealth-producing power of the people. Finally it means
from two to five million or more day- of sickness with all it- attendant
distress, pain of body, and mental depression to some unfortunate
individuals of those five State-."

Referring to the Delta region in Mississippi, which lie- along the
Mississippi River in the western part of the State of Mississippi,
extending from the month of the Yazoo River north nearly to the
Tennessee line. Herrick >ay> that it is the second be>t farming land
in the world, having onlv one rival, and that i- the vallev of the Nile
"Still." says Herrick. *" this land to-day, or at least much of it. can
be bought at ten to twenty dollars an acre. Thousands of acre- in
this region are still covered with the primeval forest, and the bears
and deer still roaming there offer splendid opportunities for the
chase, as evidenced by the late visit of our Chief Executive to those
regions for the purpose of hunting. Why is not this laud thickly
settled? And why is it not worth from two to five hundred dollars
an acre? If it produces from one to two or more bales of cotton to
an acre, and it does, it ought to be worth the above named figures.
A bale of cotton to the acre can be produced for thirteen dollar-,
leaving a net profit of twenty to forty dollars for each bale, or forty
to eighty or more dollars for each acre of land cultivated. Moreover,
this land has been doing that for years, and will do it for year- to
come, without the addition of one dollar's worth of fertilizer. Land
that will produce a net profit of forty to eighty dollars an acre i- a
splendid investment at one, two. or even three hundred dollar- an
acre. Yet this land does not sell in the market for anything like so
much, because the demand is not sufficient, for white people positively
object to living in the Delta on account of malarial chills and fevers.
A man said to me not long ago that he would go to the Delta that day
if he were sure that his own life or the lives of the members. of his
family would not be shortened thereby. There an' thousands exactly
like him. and the only reason that these thousands do not go there to
buy lands and make homes is on account of chills and fevers. But
there is a time coming, and that not far distant, when malaria in the
Delta will not menace the would-be inhabitants. When that- time
comes it will be the richest and most populous region in the United
States."

Malaria is a preventable disease. It is possible for the hitman
species to live and to thrive and to produce in malarious regions, but
at a very considerable inconvenience and expense. The Italian inves-
and especially Celli and his -tali', have shown that by

MOSQU tTOES AND M \i.\i;i \. 1 5

screening the huts of the peasants on the Roman Campagna and U\
furnishing field laborers with veils and gloves when exposed to the
night air, it is possible even in thai famous hotbed of malaria to
conduct farming operations with a minimum of trouble from the
disease. Moreover, Koch and his assistants in German East Africa
have shown that it is possible, by stamping out the disease among
human beings by the I'nv use of medicine, that a point can be gained
where there is small opportunity for the ma la rial mosquitoes to become
infected. Moreover, the work of the parties sent out by the Liverpool
School of Tropica] Medicine and other English organizations to the
west coast of Africa lias shown that by the treatment of malarial
mosquito breeding pools the pernicious coast fever may be greatly
reduced. A.gain, the work of Englishmen in the Federated Malay
States has shown that large areas may be practically freed from
malaria. The most thorough and the most satisfactory of all meas
ares consists in abolishing the breeding places of the malarial mos-
quitoes. In regions Like the Delta of the Mississippi this involves
extensive and systematic drainage, but in very many localities where
the breeding places of the Anopheles mosquitoes can be easily eradi-
cated, where they are readily located and are so circumscribed as to
admit of ea>y treatment, it is possible to rid the section of malaria
at a comparatively slight expense.

With a general popular appreciation of the industrial losses caused
primarily by the malarial mosquito and secondarily by the forms
which do not carry malaria, as indicated in the opening paragraphs;
it i> inconceivable that the comparatively inexpensive measures neces-
sary should not be undertaken by the General Government, by the
State governments, and by the boards of health of communities, just
as it is inconceivable that the individual should suffer from malaria
and from the attack- of other mosquitoes when he has individual
preventives and remedies at hand. Large-scale drainage measures
by the Genera] Government involving large sections of valuable terri-
tory have been planned and are practically under way: certain State-.
notably New Jersey and New York, are beginning to work : communi-
ties all over the country through boards of health are also beginning
to take notice, while popular education regarding the danger from
mosquitoes and in regard to remedial measures is rapidly spreading.
But all of this interest should be intensified, and the importance4 of
the work should be displayed in the most emphatic manner, and relief
from malaria and other mosquito condition- should be brought about
as speedily a- possible.

A few excellent examples of antimalarial work maybe instanced.

The latest report- on the measures taken to abolish malaria from
Klang and Port Swettenham in Selangor, Federated Malay State-.
indicate the most admirable results. These measures were tinder-

16 LOSS THROUGH INSIK "is THAT CABBY DISEASE.

takes first in L901 and L902, and have been reported upon from time
to time in the Journal of Tropical Medicine. The expenditure
undertaken by the Government with a view to improving the health
oi the inhabitants of these town- has been fully justified by the

results, which promise to be of permanent value. The total expendi-
ture for the town of Klang down to the end of 1905 was ^>.100
($15,086), and the annual permanent expenditure i> about £60 ($292)
for clearing earth drains and £210 (Sl.022) for town gardener-. For
Port Swettenham the total expenditure to the end of 100.') was l'T.000
($34,065), and the annual cost of keeping up the drain-, etc.. is ap-
proximately £40 ($195) for clearing earth drain-, and £100 ($487)
for town gardeners.

The careful tabulation of cases and deaths and of the results of
the examination of blood of children in especially drained area-
indicates the following conclusions : (1) Measure- taken systematically
to destroy breeding place- of mosquitoes in these town-, the inhabit-
ants of which suffered terribly from malaria, were followed almost
immediately by a general improvement in health and decrease in
death rate. (2) That this was due directly to the work carried out
and not to a general dying out of malaria in the district i- clearly
shown b}7 figures pointing out that while malaria has practically
ceased to exist in the areas treated it has actually increased to a
considerable extent in other parts of the district where antimalarial
measures have not been undertaken.

The statistics for 1905 are even more favorable than those for 1902,
which gives a very strong evidence in favor of the permanent nature
of the improvement carried out. In fact it seems as though malaria
has been permanently stamped out at Klang and Port Swettenham
by work undertaken in 1901, and this experience in the Malay States
should be of value to those responsible for the health of communities
similarly situated in many other parts of the world.

Another striking example of excellent work of this kind is found
in the recently published report on the suppression of malaria in
Ismailia, issued under the auspices of the Compagnie Oniverselle du
Canal Maritime de Suez. Ismailia is now a town of 8.000 inhabit-
ants. It was founded b}T De Lesseps in April. 18G2. on the borders
of Lake Timsah, which the Sue/. Canal crosses at mid-distance be-
tween the Red Sea and the Mediterranean. Malarial fever made it-
appearance in very severe form in September. 1>77. although the
city had up to that time been very healthy, and increased so that
since 1886 almost all of the inhabitants have suffered from the fever.
In 1901 an attempt to control the disease was made on the mosquito
basis, and this attempt rapidly and completely succeeded, and after
two years of work' all trace- of malaria disappeared from the city.
The work was directed not only against Anopheles mosquitoes, but

MOSQU] rOES \M> S i.l.I.nw FEVER. 1 7

against other culicids, and comprised the drainage of a large swamp
ami tin' other usual measures. The initial expense amounted to
50,000 francs ($9,650), and the annual expenses since have amounted
to about L8,300 francs ($3,532).

The results may be summarized about as follow-: Since the be-
ginning of L903 the ordinary mosquitoes have disappeared from
[smailia. since the autumn of L903 not a single larva of Anopheles
has been found in the protected /one. which extends to the west for
a distance of 1.000 meters from the first houses in the Arabian
quarter and to the east for a distance of 1,800 meters from tin1 first
houses in tin' European quarter. After L902 malarial fever obviously
began to decrease, and since 1903 not a single new case of malaria
has been found in Tsmailia.

A very efficient piece of antimalarial work was accomplished in
Havana during the American occupation of 1901 to 1902, incidental
in a way to (he work against yellow fever. An Anopheles brigade
of workmen was organized under the sanitary officer, Doctor Gorgas,
for work along the small streams, irrigated gardens, and similar
places in the suburbs, and numbered from 50 to 300 men. No exten-
sive drainage, such as would require engineering skill, was attempted,
and the natural streams and gutters were simply cleared of obstruc-
tions and grass, while superficial ditches were made through the irri-
gated meadows. Among the suburban truck gardens Anopheles bred
( verywhere, in the little puddles of water, cow tracks, horse track's,
and similar depressions in grassy ground. Little or no oil was used
by the Anopheles brigade, since it was found in practice a simple
matter to drain these places. At the end of the year it was very diffi-
cult to find water containing mosquito larvae anywhere in the suburb-,
and the effect upon malarial statistics Avas striking. In 1900, the
year before the beginning of the mosquito work, there were 325
deaths from malaria; in 1901, the first year of the mosquito work,
171 deaths; in 1902, the second year of mosquito work, 77 deaths.
Since 1902 there has been a gradual though slower decrease, as fol-
lows: 190:;. 51; 1904, 44; 1905, 32; 1906, 20; 1907, 23. These results,
although less striking than those from Ismailia, involved a smaller
expense in money and show surely an annual saving of 300 lives, and
undoubtedly a corresponding decrease in the number of malarial
cases, which may be estimated upon our earlier basis at something
less than 40,000.

YELLOW FEVER.

Yellow fever has prevailed endemically throughout the West In-
dies and in certain region- on the Spanish Main virtually since the
discovery of America. Barbados, Jamaica, and Cuba suffered
epidemics before the middle of the seventeenth century. There were
70951 Bull. 78 09 —3

18 LOSS THROUGH INSECTS THAI' CABRY DISEASE.

outbreaks in Philadelphia. Charleston, and Boston as early as 1692,
and for a hundred years there were occasional outbreaks, culminat-
ing in the great Philadelphia epidemic of 1793. Northern cities were
able, by rigid quarantine measures, to prevent great epidemics after
the early part of the nineteenth century, but from the West Indies
the disease was occasionally introduced and prevailed from time to
time epidemically in the Southern States. In 1853 it raged through-
out this region, Xew Orleans alone having a mortality of 8.000. The
lasl widespread epidemic occurred in 1878, chiefly in Louisiana, Ala-
bama, and Mississippi, but spreading up the Mississippi Valley as far
a- Cairo, 111., and attacking with virulence the city of Memphis. Tenn.
In this year there were 125.000 cases and 12.000 deaths. In 1882
there were 192 deaths at Pensacola ; in 1887, 62 deaths in the Southern
States; in 1893, 52 deaths; in 1897, 484; in 1898, 2,456 cases with
117 deaths; in 1903, 139 deaths were recorded, mostly at Laredo.
Tex., and in 1905 there was a serious outbreak at Xew Orleans and
in neighboring towns, including one locality in Mississippi, in which
911 deaths were recorded for the whole country.

The actual loss of life from yellow fever during: all these years.
when compared with the loss from other diseases, has been compara-
tively slight, but the death rate is perhaps the most insignificant fea-
ture of the devastation which yellow fever epidemics have produced,
and the disease itself has been but a small part of the affliction which
it has brought to the Southern States. The disease once discovered in
epidemic form, the whole country has become alarmed; commerce
in the affected region has come virtually to a standstill; cities have
been practically deserted ; people have died from exposure in camping
out in the highlands ; rigid quarantines have been established ; inno-
cent persons have been shot while trying to pass these quarantine
lines; all industry for the time has ceased. The commerce of the
South during the epidemic of 1878, for example, fell off 90 per cent,
and the hardships of the population can not be estimated in monetary
terms. With such industrial and commercial conditions existing
from Texas to South Carolina, many industries at the North have
suffered, and, in fact, the effect of a yellow fever summer in the South
has been felt not only all over the United States, but in many other
j^ortions of the world.

All these conditions, as bad as they have been, do not sum up the
total loss to the national prosperity during past years. Cities like
Galveston, Xew Orleans, Mobile, Memphis, Jacksonville, and Charles-
ton, subject to occasional epidemic-, as they have been in the past,
have not prospered as they should have done. Their progress has
been greatly impeded by this one cause, and thus the industrial
development of the entire South has been greatly retarded.

MOSQUITOES \.\!> VKU.nw FEVER. 1 *)

Physicians have been theorizing about the cause of vellow fever
from the time when they began to treal it. Ii was thought by many
that it was carried in the air; by other- thai it was conveyed by the
clothing, bedding, or other articles which had conic in contact with ;i
yellow-fever patient. There were one or two early suggestions of the
agency of mosquitoes, hut practically #no attention was paid to them,
and they have been resurrected and considered significant only since
the beginning of the present century. With the discovery of the
agency of micro-organisms in the causation of disease, a search soon
began for some causative germ. Many micro-organisms were found
in the course of the autopsies, and many claims were put forth by
investigators. All of these, however, were virtually set at rest by
Sternberg in his " Report on the Etiology and Prevention of Yellow
Fever,-' published in L890, but a claim made by Sanarelli in June.
ls'.>7. for a bacillus which he called Bacillus icteroides received con-
siderable credence, and in L899 it was accepted in full by Wasden and
Geddings, of the United States Marine-Hospital Service, who re-
ported th.it they had found this bacillus in thirteen or fourteen cases
of yellow fever in the city of Havana. There i< no evidence, how-
ever, that this bacillu> has anything to do with yellow fever. In L881
Finlay, of Havana, proposed the theory that yellow fever, whatever
it> cause.may be. is conveyed by means of Culex (now Stegomyia)
fust hit, is (now calopus). Subsequently he published several im-
portant papers, in which his views were modified from time to time,
and in the course of which lie mentioned experiments with 100 indi-
viduals, producing 3 cases of mild fever. Xone of the cases, however.
was under his full control, and the possibility of other method- of
contracting the disease was not excluded. Therefore, his theory,
while it was received with interest, was not considered to be proved.

In 1890 came the beginning of the true demonstration. An army
boa I'd was appointed by Surgeon-General Sternberg for the purpose
of investigating the acute infectious diseases prevailing in the island
of Cuba. The result achieved by this board, consisting of Reed.
Carroll. Lazear, and Agramonte, was a demonstration that yellow
fever is carried by Stegomyia calopus, and their ultimate demonstra-
tion was so perfect as to silence practically all expert opposition. The
Third International Sanitary Convention of the American Republics
unanimously accepted the conclusion that yellow fever is carried by
this mosquito, and that the Stegomyia constitutes the only known
mean- by which the disease is spread. To-day, after abundant addi-
tional demonstration, the original contention of Reed, Carroll, and
Agramonte (Lazear Inning died in the course of the experiments) i-
a part of the accepted knowledge of the medical world. The im-
portance of the discovery can not be overestimated, and it- firsl
demonstration was followed by antimosquito measures in the city

20 LOSS THROUGH [NSECTS THAT CABRY DISEASE.

of Havana, undertaken under the direction of Gorgas, with startling
results.

Yellow fever had been endemic in Havana for more than one hun-
dred and fifty year-, and Havana was the principal source of infec-
tion for the rest of Cuba. Other towns in Cuba could have rid
themselves of the disease if they had not been constantly reinfected
from Havana. By ordinary sanitary measures of cleanliness, im-
proved drainage, and similar mean- the death rate of the city was
reduced, from 1898 to 1900. from 100 per thousand to 22 per thou-
sand; but these measures had no effect upon yellow fever, this disease
increasing as the nonimmune population following the Spanish war
increased, and in 1900 there was a severe epidemic.

Stegomyia calopus was established as the carrier of the fever
early in 1901. and then antimosquito measures were immediately
begun. Against adult mosquitoes no general measures were attempted,
although screening and fumigation were carried out in quarters
occupied by yellow-fever patients or that had been occupied by
yellow-fever patients. It was found that the Stegomyia bred prin-
cipally in the rain-water collections in the city itself. The city was
divided into about 30 districts, and to each district an inspector and
two laborers were assigned, each district containing about a thousand
house-. An order was issued by the mayor of Havana requiring all
collections of water to be so covered that mosquitoes could not have
access, a fine being imposed in cases where the order was not obeyed.
The health department covered the rain-water barrels of poor fami-
lies at public expense. All cesspools were treated with petroleum.
All receptacles containing fresh water which did not comply with the
law were emptied and on the second offense destroyed. The result of
this work thoroughly done was to wipe out yellow fever in Havana,
and there has not been a certain endemic case since that time.

In what is termed the Xew Orleans epidemic of 1905 a striking
illustration of the value of this recently acquired mosquito-transmis-
sion knowledge is seen. The presence of yellow fever in the city was
first recognized about the 1st of July, but it was the 12th of August
before the Public Health and Marine-Hospital Service was put in
complete control of the situation. By that time the increase in new
cases and deaths rendered it practically certain that the disease was
as widespread as during the terrible epidemic of 1S7S. There had
been up to that date 1 L2 death- from a total of 913 cases, as against
L52 deaths from a total of 519 cases in L878. The Public Health and
Marine-Hospital Service, under Doctor White, took hold of the situa-
tion with energy, basing its measures almost entirely upon a warfare
against Stegomyia calopus. The disease began almost immediately
to abate, and the result at the close of the season indicated !<><> death-.
as against 4.040 in 1878, a virtual saving of over .°>..~>00 lives. The

WORK AGAINST MOSQUITOES IN PANAMA.

21

following table of deaths from yellow IVvcr in New Orleans Prom
L847 to L905 points ou1 most strikingly the value of this antimosquito

work :

Table ll. Comparative table of deaths from yellow fever in Vetc Orleans dur

ing mi ions years.

Month.

reai

1847.

1848.

1-.:;

1854.

L8 ...

1- *.

L867

May

2

31

1,621

5, 138

982

117

28

4

•>

29
632
1,234
190
131
:

■">

382

1,286

-7 1

•.17

L9

7

■1
132

1. IIH

2,204

1.1 87
22 1

1.".

1

S3

200

467

126

20

"""22'

July

71
965
l. LOO
L98
12
10
1 15

ll

1,637
1,072

in:;
26

26

l. 780

I.e.;:.

117

8

Auunsl

107

October

'i

December

Months unkiiow n

Total

•J,. sot

872

7, 848

2, 425

2, 070

4,854

3,107

1,046

460

The epidemics of is Is, L854, and L855 are least comparable with
that of 11)05 because they immediately succeeded severe epidemic- to
which were due very many immunes.

The population of New Orleans by the United States Census was
130,565 in L850; 168,675 in 18G0; 191.418 in 1870; 216,090 in 1880,
and 287,104 in 1900.

WORK ON THE ISTHMUS OF PANAMA.

The United States Government has very properly used the services
of Colonel Grorgas, who was in charge of the eminently successful
work at Havana, by appointing him chief sanitary officer of the
Canal Zone during the digging of the canal. Tn 1901 active work was
begun, and Colonel Gorgas was fortunate in having the services of
Mr. Le Prince, who had been chief of his mosquito brigades in Havana,
and therefore was perfectly familiar with antimosquito methods. In
Panama, as in Havana, the population had depended principally
upon rain water for domestic purposes, SO that every house had cis-
terns, water barrels, and such receptacles for catching and storing
rain water. The city was divided up into small districts with an in-
spector in charge of each district. This inspector was required to
cover hi- territory at least twice a week and to make a report upon
each building with regard to it- condition as to breeding places of
mosquitoes. All the cisterns, water barrels, and other water recepta-
cle- in Panama were covered as in Havana, and in the water barrels
spigots were inserted so that the covers would not have to be taken
off. Upon first inspection, in March. I.OOO breeding places were
reported. At the end of October le— than tOO containing larva*
were recorded. This gives one a fair idea of the consequent rapid

22 LOSS THBOUGH INSECTS THAT CARRY DISEASE.

decrease in the number of mosquitoes in the city. These opera-
tion- were directed primarily against the yellow-fever mosquito, and
incidentally against the other common species that inhabit rain-water
barrels. Against the Anopheles in the suburbs the same kind of work
was done as was done in Havana, with exceptionally good results.

The -ainc operation- were carried on in the villages between Pan-
ama and Colon. There are some twenty of these villages, running
from .")<)() to 3.000 inhabitants each. Not a single instance of failure
has occurred in the disinfection of these small towns, and the result
of the whole work has been the apparent elimination of yellow fever
and the very great reduction of malarial fever.

The remarkable character of these results can only be judged accu-
rately by comparative methods. It is well known that during the
French occupation there was an enormous mortality among the
European employee-, and this was a vital factor in the failure of the
work. Exact losses can not be estimated, since the work was done
under 17 different contractors. These contractors were charged $1
a day for every sick man to be taken care of in the hospital of the
company. Therefore it often happened that when a man became
sick his emplo3Ter discharged him. so that he would not have to bear
the expense of hospital charges. There was no police patrol of the
territory and many of these men died along the line. Colonel
Gorgas has stated that the English consul, who was at the Isthmus
during the period of the French occupation, is inclined to think
that more deaths of employees occurred out of the hospital than in it.
A great many were found to have died along the roadside wddle en-
deavoring to find their way to the city of Panama. The old superin-
tendent of the French hospital states that one day 3 of the medical
staff died from yellow fever, and in the same month 9 of the medical
staff. Thirty-six Roman Catholic sisters were brought over as nurses,
and 2-1 died of yellow fever. On one vessel 18 young French engi-
neers came over, and in a month after their arrival all but one died.

Xow that the relation of the mosquito to yellow fever is well under-
stood, it was found during the first two years under Doctor Gorgas
that, although there were constantly one or more yellow-fever cases
in the hospital, and although the nurses and physicians were all non-
immunes, not a single case of yellow fever was contracted in that
The nurses never seemed to consider that they were running

way.

—

any risk in attending yellow fever cases night and day in screened
ward-, and the wives and families of officers connected with the hos-
pital lived about the grounds, knowing that yellow fever was con-
stantly being brought into the ground- and treated in near-by build-
ings. Americans, sick from any cause, had no fear when being
treated in beds immediately adjoining those of yellow-fever pa-
tients. Colonel Gorgas and Doctor Carter lived in the old ward

THE TYPHOID FLY, OR SOUSE I \.\ . 23

used by the French for their officers, and Colonel Gorgas thinks it

safe to say that more men had died from yellow fever in that build
ing under the French regime than in any other building of the same
capacity at present standing. He and Doctor Carter had their wives
and children with them, which would formerly have been considered
the height of recklessness, but they looked upon themselves, under the
now recognized precautions, as being as safe, almost, as they would
have been in Philadelphia or Boston.

No figures of the actual cost of the antimosquito work, either in
Havana or in the Panama Canal Zone, are accessible to the writer.
but it is safe to say that it was not exorbitant, and that it was not
beyond the means of any well-to-do community in tropical regions.

THE TYPHOID FLY, COMMONLY KNOWN AS THE HOUSE FLY.

The name "typhoid fly" is here proposed as a substitute for the
name "house fly," now in general use. People have altogether too
long considered the house fly as a harmless creature, or. at the most.
simply a nuisance. While scientific researches have shown that it i-
a most dangerous creature from the standpoint of disease, and while
popular opinion is rapidly being educated to the same point, the
retention of the name house fly is considered inadvisable, as perpetu-
ating in some degree the old ideas. Strictly speaking, the term
•'typhoid fly" is open to some objection, as conveying the erroneous
idea that this fly is solely responsible for the spread of typhoid, but
considering that the creature is dangerous from every point of view,
and that it is an important element in the spread of typhoid, it
seems advisable to give it a name which is almost wholly justified and
which conveys in itself the idea of serious disease. Another repul-
sive name that might be given to it is "manure fry," but recent
researches have shown that it is not confined to manure as a breeding
place, although perhaps the great majority of these flies are born
in horse manure. For the end in view, "typhoid fly " is considered
the best name.

The true connection of the so-called house fly with typhoid fever
and the true scientific evidence regarding its role as a carrier of that
disease have only recently been worked out. Colli in 1888 fed flies
with pure cultures of the typhoid bacillus, and examined their
contents and dejection- microscopically and culturally. Inocu-
lations of animals were also made, proving that the bacilli which
passed through flies were virulent. Dr. George M. Kober, familial*
with Celli's researches, in his report on the prevalence of typhoid
fever in the District of Columbia, published in L895, called especial
attention to the danger of the contamination of food supplies by

24 LOSS THROUGH [NSECTS THAT CARRY DISEASE.

flies coming from the excreta of typhoid patient-. The prevalence of
typhoid fever in the concentration camp- of the United State- Army
in the summer of L898 brought about the appointment of an army
typhoid commission consisting of Drs. Walter Reed, U. S. Army.
Victor M. Vaughan, U. S. Volunteers, and E. (). Shakespeare, CJ. S.
Volunteers. A paper read by Doctor Vaughan before the annual
meeting of the American Medical Association at Atlantic City, X. J.,
June 6, L900, contained the following conclusions with regard to
flies:

"27. Flies undoubtedly served as carriers of the infection.

"My reasons Tor believing that flies were active in the dissemina-
tion of typhoid may be stated as follows:

" a. Flies -warmed over infected fecal matter in the pits and then
visited and fed upon the food prepared for the soldiers at the mess
tent-. In some instances where lime had recently been sprinkled
over the contents of the pits, flies with their feet whitened with lime
were seen walking over the food.

" b. Officers whose mess tents were protected by means of screens
suffered proportionately less from typhoid fever than did those
whose tents were not so protected.

" c. Typhoid fever gradually disappeared in the fall of 1898, with
the approach of cold weather, and the consequent disabling of the fly.

" It is possible for the fly to carry the typhoid bacillus in two
ways. In the first place, fecal matter containing the typhoid germ
may adhere to the fly and be mechanically transported. In the
second place, it is possible that the typhoid bacillus may he carried
in the digestive organs of the fly and may be deposited with its
excrement."'

There were also many important conclusions which bear upon the
fly question. For example, it was shown that every regiment in the
United States service in 1898 developed typhoid fever, nearly all of
them within eight weeks after assembling in camps. It not only
appeared in every regiment in the service, but it became epidemic
both in small encampments of not more than one regiment and in the
larger ones consisting of one or more corp>. All encampments
located in the Northern as well as in the Southern States exhibited
typhoid in epidemic form. The miasmatic theory of the origin of
typhoid fever and the pythogenic theory were not supported by
the investigations of the commission, but the doctrine of the specific

"This theory is founded upon the belief that the colon germ may undergo a
ripening process by means of which its virulence is so increased and altered
thai it may be converted into the typhoid bacillus <>r at least may become the
active agent in the causation of typhoid fever.

Til E TYPHOID PLY, OB HOUSE \'\.\ . 25

origin of tin' fever was confirmed. The conclusion was reached that
the fever is disseminated by the transference of the excretions of an
infected individual to the alimentary canals of others, and thai a
man infected with typhoid fever may scatter the infection in every
latrine or regiment before the disease is recognized in himself, while
germs may be found in the excrement for a long time after the
apparently complete recovery of the patient, [nfected water was
not an important factor in the spread of typhoid in the national
encampments of L898, but about one-fifth of the soldiers in the
national encampments in the United States during that summer de-
veloped this disease, while more than SO per cent of the total death-
wen' caused by typhoid.

In iv.>;> the writer began the study of the typhoid or house fly
under both country and city conditions. lie made a rather thorough
investigation of the insect fauna of human excrement, and made a
further investigation of the species of insects that are attracted to
food supplies in houses. In a paper entitled "A Contribution to the
Study of the Insect Fauna of Unman Excrement (with special refer-
ence to the spread of typhoid fever by flies),'* published in the Pro-
ceedings of the Washington Academy of Sciences, Volume II, pages
541 604, December 28, 1900, he showed that 98.8 per cent of the whole
number of insects captured in houses throughout the whole country
under the conditions indicated above were Musca domestica, the
typhoid or house fly. He showed further that this fly, while breeding
most numerously in horse stables, is also attracted to human excre-
ment and will breed in this substance. It was shown that in towns
where the box privy was still in existence the house fly is attracted to
the excrement, and. further, that it is so attracted in the filthy regions
of a city where sanitary supervision is lax and where in low alleys
and corner- and in vacant lots excrement is deposited by dirty people.
He stated that he had seen excrement which had been deposited over-
night in an alleyway in South Washington swarming with flies under
the bright sunlight of a June morning (temperature 92° F.), and that
within 30 feet of these deposits were the open windows and doors of
the kitchens of two houses kept by poor people, these two houses
being only elements in a long row. The following paragraph is
quoted from the paper just cited:

" Now. when we consider the prevalence of typhoid fever and that
virulent typhoid bacilli may occur in the excrement of an individual
for some time before the disease i- recognized in him. and that the
same virulent germs may be found in the excrement for a long time
after the apparent recovery of a patient, the wonder is not that ty-
phoid is SO prevalent but that it does not prevail to a much greater

20 Loss I lllturoil INSECTS THAT CAREY DISEASE.

extent. Box privies should be abolished in every community. The
depositing of excrement in the open within town or city Limits should
be considered a punishable misdemeanor in communities which have
not already such regulations, and it should be enforced more rigor-
ously in towns in which it is already a rule. Such offenses are gener-
ally committed after dark, and- it is often difficult or even impossible
to trace the offender; therefore, the regulation should be carried even
further and require the first responsible person who notice- the de-
posit to immediately inform the police, so that it may be removed or
covered up. Dead animals are so reported: hut human excrement is
much more dangerous. Boards of health in all communities should
look after the proper treatment or disposal of horse manure, primarily
in order to reduce the number of house Hie- to a minimum, and all
regulations regarding the disposal of garbage and foul matter should
he made more stringent and should be more stringently enforced."

In the opening sentence of the paragraph just quoted attention was
called to the activity of bacilli in excreta passed by individual- after
apparent recovery from typhoid. Since the paper in question was
published, more especial attention has been drawn by medical men
to this point, and it has been shown that individual- who are chronic
spreaders of the typhoid germs are much more abundant than was
formerly supposed. Dr. George A. Soper recently discovered a strik-
ing case of this kind in the person of a cook employed successively
by several families in the vicinit}^ of Xew York City, with the result
that several cases of typhoid occurred in each of these families. In
a paper by Doctor Davids and Professor Walker, read before the
Royal Sanitary Institute of London during the present season, the
history was given of four personal carriers of typhoid who had com-
municated the disease to a number of people. The>e four carriers
were detected in one city within a few months, and from this fact
it can be argued with justice that such cases are comparatively numer-
ous. This being true, the presence of unguarded miscellaneous
human excreta deposited in city suburbs, in vacant lots, and in low-
alleyways intensifies to a very marked degree the danger that the food
will become contaminated with typhoid bacilli by means of the ty-
phoid or house fly. It is known, too, that the urine of persons who
have suffered from typhoid fever often contains active typhoid bacilli
for several weeks after the patients have recovered: consequently this
also is a source of danger.

The importance of the typhoid fly a- a carrier of the disease in
army camps, as shown in the Spanish war and in the Boer war and
in the camps of great armies of laborers engaged in gigantic enter-
prises like the digging of the Panama canal, is obvious, bttt what

I III TYPHOID II. \ , OB HOUSE \'\.\ . - 7

has ju>t been stated indicates that even under city conditions tin
influence of this fly in the spread of this disease has been greatlj
underestimated, li is not claimed thai under city conditions the
house llv becomes by this argument a prime factor in the transfer
of the disease, but it must obviously take a much higher relative
rank among typhoid conveyers than it has hitherto assumed. Per
haps even under city conditions it must assume third raid; -next to
water and milk.

It i- not alone as a carrier of typhoid that this fly is to be feared.
In the same way it may carry nearly all the intestinal diseases. It
is a prime agent in the spreading of summer dysentery, and in this
way is unquestionably responsible for the death of many children
in summer. One of the earliest accurate scientific studies of the
agency of insects in the transfer of human disease was in regard to
Hit'- as spreaders of cholera. The belief in this agency long pre-
ceded its actual proof. Dr. (i. E. Nicholas, in the London Lancet.
Volume II. 1873, page 724, is quoted by Xuttall as writing as follows
regarding the cholera prevailing at Malta in L849: "My first im-
pression of the possibility of the transfer of the disease by flies was
derived from the observation of the manner in which these voracious
creatures, present in great numbers, and having equal access to the
dejection- and food of patients, gorged themselves indiscriminately
and then disgorged themselves on the food and drinking utensils.
In L850 the Superb, in common with the rest of the Mediterranean
squadron, was at sea for nearly six months; during the greater part
of the time she had cholera on board. On putting to sea, the flies
were in great force: but after a time the flies gradually disappeared,
and the epidemic slowly subsided. On going into Malta Harbor,
but without communicating with the shore, the Hies returned in
greater force, and the cholera also with increased violence. After
more cruising at sea, the (lies disappeared gradually with the subsi-
dence of the disease."

Accurate scientific bacteriological observations by Tizzoni and
Cattani in lss<> showed definitely active cholera organisms in the
dejecta of flies caught in the cholera wards in Bologna, Italy. These
observations were subsequently verified and extended by Simonds,
Offelmann, Macrae, and other.-.

With tropical dysentery and other enteric diseases practically the
same condition- exist. In ;i report by Daniel I). Jackson to the
committee on pollution, of the Merchants' Association in New York,
published in December. L907, the results of numerous observations
upon the relation of Hie- to intestinal diseases are published, ami the
relation of deaths from intestinal diseases in New York Citv to the

28 LOSS THROUGH INSECTS THAT CABBY DISEASE.

activity and prevalence of the common house fly is shown not only
by repeated observations but also by an interesting plotting of the
curve of abundance of flies in comparison with the plotted curve of
abundance of death- from intestinal diseases, indicating that the
test number of flies occurred in the weeks ending July 27 and
August 3; also, that the deaths from intestinal diseases rose above
the normal at the same time at which flies became prevalent, culmi-
nated at the same high point, and fell off with slight lag at the
time of the gradual falling off of the prevalence of the insects.

Similar studies have beeu carried on during the summer of L908
in the city of Washington, and the curve of typhoid-fly abundance
for the whole city, as well as that for a district comprising eight city
squares in which intensive studies have been made both of flies and
i f disease, will be plotted at the close of the season. At the time
of present writing this work has not been completed.

The typhoid fly also possesses importance as a disseminator of the
bacilli of tuberculosis. In a paper by Dr. Frederick T. Lord, of
Boston, reprinted from the Boston Medical and Surgical Journal for
December 15, 190i. pages 651-654. the following conclusions are
reached:

" 1. Flies may ingest tubercular sputum and excrete tubercle ba-
cilli, the virulence of which may last for at least fifteen day-.

*• 2. The danger of human infection from tubercular flyspecks is
by the ingestion of the s'pecks on food. Spontaneous liberation of
tubercle bacilli from flyspecks is unlikely. If mechanically dis-
turbed, infection of the surrounding air may occur.

"As a corollary to these conclusions, it is suggested that —

" 3. Tubercular material ( sputum, pus from discharging sinuses.
fecal matter from patient- with intestinal tuberculosis, etc.) should
be carefully protected from flies, lest they act a> disseminators of the
tubercle bacilli.

" 4. During the fly season greater attention should be paid to the
screening of rooms and hospital wards containing patients with
tuberculosis and laboratories where tubercular material is examined.

" 5. As these precautions would not eliminate fly infection by
patients at large, foodstuffs should be protected from flies which may
already have ingested tubercular material."

From all these Pacts it appears that the most important part played
by the typhoid fly or house fly in the human economy is to carry
bacteria from one place to another. The following table and com-
ments are taken from Bulletin No. 51 (April. 1908), of the Storrs
Agricultural Experiment Station. Storrs, Conn., entitled " Sources of
Bacteria in Milk," by W. M. E>ten and C. J. Mason:

THE CYPHOID FLY, OB BOUSE FLY.
Table 111. Sources of bacteria from flies.

29

Total Total acid
lumber. bacteria.

1807.
July 27

July 27

Aug. 6

A.m.! I

a.ug.14

Sept i

Bept.21

8ept21

Bept.27

A.ug.20

i. 0 l fly, bacteriological

laboratory

[b) l fly, bacteriological

laboratory

id 19 cow stable flies

Average per fly

swill-barrel flies....

Average per By

(t) Ml pigpen Hies

Average per fly

/) 18 swill-barrel flies....

Average per fly

[g] 80 dwelling-house flies.

A\ erage per By

(h) 26dwelling-house flies.

Average per fly

i no dwelling-house flies.

Average per fly

tj) l large bluebottle
blowih

3, 160

550
,980,000

420,000
,000,000
,660,000
,000,000

928,000

sun. i inn
.inn. (MM)

126,000
17,680

880,

880,

600, I

322,700

308. 700

Total average of 41 1 flies.. 1,222, 570
Average per cent of n I

flies

Average per fly of 256

flies, experiments (d),

(< i, and (/) 3,0(51,000

Average per cent of 256 i

flies, experiments (d),
'V and (/ i

LOO

in >i>

600

mm
800

Tim
I

ooo

000

I C7

ooo

nun

(Mill

200

Rapid

Slow

liquefy liquefj

mil- bac oil; bac
teria. teria.

lactw
Group \.

Group \
Class 2.

nun

0
0
0
0
0
100,000
700

I)

0

0

0

120,000

1,600

\Mn.

Ni.:;nn

I uu

0
20,000

I. nun

0

0

266,000

I. 150
i i. ioo ooo

804,1

L2.600
117

34, I

L,300

125,000

I. inn

16,000

1,631 '

19,300

1, 176,000

12,200

30,000,000

367, 300
30

165, 000

7 830

230

268,700

18

" 2,200 mold spores.

" From the above table the bacterial population of 414 flies is pretty
well represented. The domestic fly is passing from a disgusting nui-
sance and troublesome pest to a reputation of being a dangerous
enemy to human health. A species of mosquito has been demon-
strated to be the cause of the spread of malaria. Another kind of
mosquito is the cause of yellow fever, and now the house fly is con-
sidered an agency in the distribution of typhoid fever, summer coin-
plaint, cholera infantum, etc.

"The numbers of bacteria on a single fly may range all the way
from 550 to 6,600,000. Early in the fly season the numbers of bac-
teria on flies are comparatively small, while later the numbers arc
comparatively vvvy large. The place where flies Live also determines
largely the numbers thai they carry. The average for the 11! flies
was about one and one-fourth million bacteria on each. Il hardly
seems possible for so small a bil of* life to carry so large a number of
organisms. The method of the experiment was to catch the flies from
the several sources by means of a sterile fly net, introduce them into
a sterile bottle, and pour into the bottle a known quantity of steril
ized water, then -hake the bottle to wash the bacteria from their
bodies, to simulate the number of organisms that would come from a
fly in falling into a lot of milk. In experiments '<L' ' < .' and ■ /' "

30 L<»>> THBOTJGB [NSECTS THAT CABBY DISEASE.

the bacteria were analyzed into four groups. The objectionable class,
coli-cerogenes type, was two and one-half times as abundant as the
favorable acid type. If these flies stayed in the pigpen vicinity there
would be less objection to the flies and the kind- of organisms they
cany, but the fly is a migratory insect and it visits everything s under
the -iin." It i- almost impossible to keep it out of our kitchens, din-
ing room-, cow -tabic-, and milk room-. The onlv remedy for thi-
rather serious condition of things is. remove the pigpen a- far a- pos-
sible from the dairy and dwelling house. Extreme care should be
taken in keeping flies out of the cow -table, milk rooms, and dwell-
ings. Flic- walking over our food are the cause of one of the worst
contaminations that could occur from the standpoint of cleanliness
and the danger of distributing disease germs."

The danger of the typhoid or house fly in the carriage of disease
has thus been abundantly demonstrated. Further than thi-. it is an
intolerable nuisance. With mosquitoes it necessitates an annual out-
lay for window and door screens in the United States of not less than
ten millions of dollars. As a carrier of disease it causes a loss of
many millions of dollars annually. Dr. G. X. Kober. in a paper pre-
pared for the Governors* Conference on the Conservation of Natural
Resources, held at the White House in May, 1908, entitled ;" The Con-
servation of Life and Health by Improved Water Supply." presented
figures showing that the decrease in the vital assets of the country
through typhoid fever in a single year is more than s:].">0.000.000.
The house fly. as an important agent in the spread of thi- disease, is
responsible for a very considerable portion of this decrease in vital
assets. A- an agency in the spread of other intestinal diseases, this
sum must be greatly increased, and yet it is allowed t>> breed unre-
stricted all over the United States; it i< allowed to enter freely the
houses of the great majority of our people: it is allowed to spread
bacteria freely over our food supplies in the market- and in the
kitchens and dining rooms of private houses, and. to use the happy
phraseology of Dr. Theobald Smith. " when we go into public restau-
rants in midsummer we are compelled to light for our food with the
myriads of house flies which we find there alert, persistent, and
invincible."

Even if the typhoid or house fly were a creature difficult to de-
stroy, t lie general failure on the part of communities to make any
efforts whatever to reduce it> numbers could properly be termed
criminal neglect; but since, as will be shown, it i- comparatively an
easy matter to do away with the plague of flic-, thi- neglect becomes
an evidence of ignorance or of a carelessness in regard to disease-
producing filth which to the informed mind constitutes a serious blot
on civilized methods of life.

Til E TYPHOID FLY, OB HOUSE PLY. 3 1

Strange as it may seem, an exhaustive study of the conditions
which produce house Hies in numbers has never been made. The
life history of the insect in general was, down to L873, mentioned in
only three European work- and few exact Pacts were given. In L873
Dr. A. S. Packard, then of Salem, Mass., studied the transformations
of the insect and gave descriptions of all stages, showing thai the
growth of a generation from the egg slate1 to the adult occupies from
lo to 1 I days.

In lsi).') the writer traced the life history in question, indicating
that L20 eggs arc laid by a single female, and that in Washington,
in midsummer, a generation is produced every LO days. Although
numerous substances were experimented with, he was able to breed
the fly only in horse manure. Later investigations indicated that the
fly will breed in human excrement and in other fermenting vegetable
and animal material, hut thai the1 vast majority of the Hie- that
infesl dwelling houses, both in cities and on farms, come from horse
manure.

In L907 careful investigations carried on in tin1 city of Liverpool
by Robert Newstead, lecturer in economic entomology and para-
sitology in the School of Tropical Medicine of the University of
Liverpool, indicated that the chief breeding places of the house fly
in that city should he classified under the following head-:

(1) Middensteads (places where dung is stored) containing* horse
manure only.

(2) Middensteads containing spent hops.

(3) Ash pits containing fermenting materials.

He found that the dung heaps of stables containing horse manure
only were the chief breeding places. Where horse and cow manures
were mixed the Hies bred less numerously, and in barnyards where
fowls were kept and allowed freedom relatively few of the house
llie> were found. Only one midden containing warm -pent hops was
inspected, and this was found to be as badly infested as any of the
.-table middens. A great deal of time was given to the inspection of
ash pit-, and it was found that wherever fermentation had taken
place and artificial heat had been thus produced, such places were
infested with house-fly larvae and pupae, often to the same alarming
extent as in -table manure. Such ash pits as these almost invariably
contained large quantities of old bedding or straw and paper, paper
mixed with human excreta, or old rags, manure from rabbit hutches,
etc. or a mixture of all these. About 25 per cent of the ash pits
examined were thus infested, and house flies were found breeding
in smaller uumbers in ash pits in which no heat had been engendered
by fermentation. The house fly was also found breeding by Mr.
stead in certain temporary breeding places, such as collection-

32 LOSS THBOTTGB [NSECTS THAT CAERY DISEASE.

of fermenting vegetable refuse, accumulations of manure at the
wharves, and in bedding in poultry pens.

Still more recent investigations were carried on during 1908 by
Prof. S. A. Forbes, State entomologist of Illinois, who Ik;- reared it
in large numbers from the contents of paunches of slaughtered cattle.
from refuse hog hair-, from tallow vats, from carcasses of various
animal-, miscellaneous garbage, and so on.

All this mean- that if we allow the accumulation of tilth we will
have house Hie-, and if we do not allow it to accumulate we will have
no house flies. With the careful collection of garbage in can- and
the removal of the contents at more frequent interval.- than 10 day-.
and with the proper regulation of abattoirs, and more particularly
with the proper regulation of stables in which horses are kept, the
typhoid fly will become a rare species. Tt will not be neces-ary to
treat horse manure with chlorid of lime or with kerosene or with a
solution of Paris green or arsenate of lead, if stable men are required
to place the manure daily in a properly covered receptacle and if it
is carried away once a week.

The orders of the health department of the District of Columbia,
published May 3, 1900. if carried out will be very effective. These
orders may be briefly condensed as follows:

All stalls in which animals are kept shall have the surface of the
ground covered with a water-tight floor. Every person occupying
a building where domestic animals are kept shall maintain, in con-
nection therewith, a bin or pit for the reception of manure, and pend-
ing the removal from the premises of the manure from the animal
or animals shall place such manure in said bin or pit. This bin .-hall
be so constructed as to exclude rain water, and shall in all other re-
spects be water-tight, except as it may be connected with the public
-ewer. It shall be provided with a suitable cover and constructed
so as to prevent the ingress and egress of flies. Xo person owning
a stable shall keep any manure or permit any manure to be kept in
or upon any portion of the premises other than the bin or pit de-
scribed, nor shall he allow any such bin or pit to be overfilled or
needlessly uncovered. Horse manure may be kept tightly rammed
into well-covered barrels for the purpose of removal in such barrels.
Every person keeping manure in any of the more densely populated
part- of the District shall cause nil such manure to be removed from
the premises at least twice every week between June 1 and October 31,
and at least once every week between November 1 and May 31 of
the following year. No person shall remove or transport any manure
over any public highway in any of the more densely populated parts
of the District except in a tight vehicle, which, if not inclosed, must
be effectually covered with canvas, -<> a- to prevent the manure from
being dropped. No person -hall deposil manure removed from the

nil. n PHOID PLY, OB HOUSE n\ . S3

bins or pits within any of the more densely populated parts of the
District without a permit from the health officer. Any person
violating any of these provisions shall, upon conviction thereof, be
punished by a fine of not more than $40 for each offense.

In addition to this excellent ordinance, others have been issued
from the health department of the District of Columbia which provide

against the contamination of exposed food by Hies and by dust. The

ordinances are excellently worded so as to cover all possible cases.

They provide4 for the registration of all stores, market-, cafes, lunch
rooms, or of any other place where food or beverage is manufactured
or prepared for -ale. stored for sale, offered for sale, or sold, in order
to facilitate inspection, and still more recent ordinances provide for
the registration of stables. An excellent campaign was begun during
the summer of L908 against insanitary lunch rooms and restaurants.
A Dumber of case- were prosecuted, hut conviction was found to he
difficult.

For one reason or another, the chief reason being the lack of a
sufficient force of inspectors under the control of the health officers,
the ordinance in regard to stables has not been carried out with that
perfection which the situation demands. In the summer of 189G, the
health officer of the District, Dr. W. C. Woodward, designated ;i
region in Washington bounded by Pennsylvania avenue, Sixth street,
Fifteenth street, and the Potomac River, which was to be watched
by assistants of the writer. Twent}T-four stables were located in this
region and were visited weekly by two assistants chosen for the pur-
pose. The result was that on the wdiole the manure wTas well looked
after and the number of flies in the region in question was very con-
siderably reduced during the time of inspection.

Were simple inspection of stables all that is needed, a force of four
inspectors, specially detailed for this work, could cover the District
of Columbia, examining every stable, after they were once located and
mapped, once a week. The average salary of an insj^ector is $1,147,
so that the total expense for the first year wrould be something like4
$ 1,500. But the inspectors' service is complicated by the matter of
prosecution. Much of the time of inspectors would be taken in the
prosecution of the owners of neglected premises. Moreover, the health
officer has found during the summer of 1908, in his prosecution of the
owners or managers of insanitary restaurants, that his inspector- were
practically -worn out of court by the multiplicity of opposing evi-
dence. This means that it will be necessary in such cases to -end two
inspectors together in all cases, so that the testimony of one may be
supported by the testimony of the other. This, perhaps, would double
the number of necessary inspectors, making the expense of the service
something over $9,000. It i> reasonably safe to state, however, thai

34 LOSS THROUGH INSIK IS THAT ( AitKY DISEASE.

with such an expense for competent service, or perhaps with a slightly

added expense, the typhoid fly could be largely eliminated as an ele-
ment in the transfer of disease in the District of Columbia, and the
difficulty which the authorities have had in locating the cause of a
\cr\ considerable proportion of the cases of typhoid in the District
for the past two or three years indicate- plainly to the mind of the
writer that the typhoid fly is a much more important clement than
has been supposed. It is a comforting although comparatively insig
nificant fact and a matter of common observation that in certain
sections of the city the typhoid fly has been much Less numerous dur-
ing the past summer than in previous years. The writer is inclined
t<> attribute this to the gradual disappearance of horse -table- in
.-uch sections, brought about by the rapidly increasing use of motor
vehicles.

A -ignificant paragraph in Mr. Newstead's Liverpool report, re-
ferred to above, contains the following words: "The most strenuous
efforts should be made to prevent children defecating in the courts
and passages; or that the parents should be compelled to remove such
matter immediately ; and that defecation in stable midden- should be
strictly forbidden. The danger lies in the overwhelming attraction
which such fecal matter has for house flies, which later may come into
direct contact with man or his foodstuffs. They may, as Veeder puts
it. ' In a very few minutes * * * load themselves with dejections
from a typhoid or dysenteric patient, not as yet sick enough to be in
hospital or under observation, and carry the poison so taken up into
the very midst of the food and water ready for use at the next meal.
There is no long, roundabout process involved." "

The writer has already referred to this general subject in his re-
marks on the depositing of excrement in the open within town or city
limit-, but Xewstead's specific reference to children reminds one that
in the tenement districts of the older great cities of England and other
parts of Europe there occur opportunities for transfer of disease
which, while probably less numerous in the newer cities of the United
States, nevertheless must still exist and be a constant danger.

We have thus shown that the typhoid or house fly is a general and
common carrier of pathogenic bacteria. It may carry typhoid fever,
Asiatic cholera, d3-sentery, cholera morbu-. and other intestinal dis-
eases; it may carry the bacilli of tuberculosis and certain eye diseases :
it is everywhere present, and it is disposed of with comparative ease.
It is the duty of every individual to guard so far as possible against
the occurrence of flies upon his premises. It is the duty of e\ cry com-
munity, through its board of health, to spend money in the warfare
against this enemy of mankind. This duty is a- pronounced as though
the communitv were attacked by bands of ravenous wolves.

tii i. TYPHOID n.v. 01: HOUSE FLY. B5

A^ a matter of Tact, large sums of money arc spent annually in the
protection of property in the [Jnited States. Large sums of money
arc spent also in health matter-: but the expenditure for protection
from flies is \'o\'\ small and is misdirected. There is much justifies
tion for the following criticism published editorially in the Journal
of the American Medical Association for August 22, L908, under the
caption, "National Farm Commission and Rural Sanitation:"

"The President calls attention to the fact that all efforts to aid the
farmers have hitherto been directed to improving their material
welfare, while the man himself and his family have been neglected.
Nowhere i- this more marked than in the attitude of the General
Government in matters relating to sanitation. It is a trite saying
that whereas the Government, through the Department of Agricul-
ture, aids the farmer generously in carina- for the health of his hogs,
sheep, etc.. it does nothing for his own health. The Government
issues notices to the farmer of the injury done to his crop- by the
cotton-boll weevil and the potato bugs and how to combat them, hut
the injury the mosquito does in spreading malaria to the people who
pick the cotton and hoe the potatoes is not impressed on him. The
fact that horseflies may carry anthrax to his cattle is dealt with at
considerable length, but the diseases which the house fly spreads to
the milk and to the farmer's family attract practically no attention.
How to build a hogpen or a sanitary barn is the subject of a number
of government publications, but how to build a sanitary privy which
will prevent the spread of typhoid, hook worm, and many other dis-
eases is regarded as of strictly local interest."

But this criticism is not entirely justified, since there was published
by the Bureau of Entomology of the United States Department of
Agriculture, in 1900, a Farmers' Bulletin, entitled "How Insects
Affect Health in Rural Districts," a in which all of these points men-
tioned by the editor of the Journal of the American Medical Asso-
ciation have been touched upon, and at the date of present writing
102.000 copies of this bulletin have been distributed among the
people. Moreover, a number of years ago a circular6 was published
on the subject of the house fly, calling attention to it- dangers and
giving instructions such as are covered in a general way in this
article, and smio 18,000 copies of this circular have also been dis-
tributed. This is an indication that the General Government is by
no mean- blind to the people's needs in such matter- as we have
under consideration, but further work should be done. That the
English Government is awaking to the same need is shown by the
fact that, in the parliamentary vote of the present year in aid of

" Farmers' Bulletin No. L55.

bCircnlar No. 35, Bureau of Entomology, L891, afterwards reissued in revised

form as Circular No. 71.

36 LOSS Tintortiii insects that carry disease.

x-icntiiic investigations concerning disease, one of the projects sup-
ported by the General Government was the investigation of Doctors
Copeman and NuttaU on flies as carriers of disease.

A leading editorial in an afternoon paper of the city of Washing-
ton, of October 20, 1908. bears the heading, "Typhoid a National
Scourge," arguing that it i- to-day as great a scourge as tuberculosis.
The editorial writer might equally well have used the heading •'Ty-
phoid a National Reproach," or perhaps even "Typhoid a National
Crime," since it is an absolutely preventable disease. And a- for the
typhoid fly. that a creature horn in indescribable filth and absolutely
swarming with disease germs should practically be invited to mul-
tiply unchecked, even in great centers of population, is surely nothing
less than criminal.

ENDEMIC DISEASE AS AFFECTING THE PROGRESS OF NATIONS.

In referring to the spread of malaria in Greece, the relation of this
disease to the rise and fall of national power has been touched upon
in an earlier paragraph of this bulletin (p. 9). The subject is one of
the widest importance and deserves a more extended consideration.

The following paragraphs are quoted from Ronald Ross's address
on Malaria in Greece, delivered before the Oxford Medical Society.
November 29, 1906:

" Now, what must be the effect of this ubiquitous and everlasting
incubus of disease on the people of modern Greece? Remember that
the malady is essentially one of infancy among the native population.
Infecting the child one or two years after birth, it persecutes him
until puberty with a long succession of febrile attacks, accompanied
by much splenomegaly and anaemia. Imagine the effect it would
produce upon our own children here in Britain. It is true that our
children suffer from many complaints — scarlatina, measles, whoop-
ing cough — but these are of brief duration and transient. But now
add to these, in imagination, a malady which lasts for years, and may
sometimes attack every child in a village. What would be the
effect upon our population — especially our rural population — upon
their numbers and upon the health and vigour of the survivors? It
must be enormous in Greece. People often seem to think that such a
plague strengthens a race by killing off the weaker individuals; but
this view rests upon the unproven assumption that it is really the
weaker children which can not survive. On the contrary, experience
seems to -how that it is the stronger blood which suffers most — the
fair, northern blood which nature attempts constantly to pour into
the southern lands. If this be true, the effect of malaria will be
constantly to resisl the invigorating influx which nature ha- provided ;
and there are many facts in the history of India. Italy, and Africa
which could be brought forward in support of this hypothesis.

ENDEMIC DISEASE EFFECTING PROGRESS OF nations. 37

"We now come face to face with thai profoundly interesting
subject, the political, economical, and historical significance of this
greal disease. We know thai malaria must have existed in Greece
ever since the time of Hippocrates, about loo B. C. What effect
has it had on the life of the country? In prehistoric times Greece
was certainly peopled by successive waves of An an invaders from the
north — probably a fair-haired people — who made it what it became,
who conquered Persia and Egypt, and who created the sciences,
arts, and philosophic- which we are only developing further to-
day. Thai race reached its climax of development at the time of
Pericles. Those greal and beautiful \ alleys were thickly peopled
by a civilization which in some ways has not been excelled.
Everywhere there wen1 cities, temples, oracles, arts, philosophic-,
and a population vigorous and well trained in arm-. Lake Kopais,
now almost deserted, was surrounded by towns whose massive works
remain to this day. Suddenly, however, a blight fell over all. Was
it due to internecine conflict or to foreign conquest? Scarcely: for
history show- that war hums and ravages, but does not annihilate.
Thebes was thrice destroyed, hut thrice rebuilt. Or was it due to
some cause, entering furtively and gradually sapping away the
energies of the race by attacking the rural population, by slaying
the new-born infant, by seizing the rising generation, and especially
by killing out the fair-haired descendant of the original settlers,
leaving behind chiefly the more immunised and darker children of
their captives, Avon by the sword from Asia and Africa?

" I can not imagine Lake Kopais, in its present highly malarious
condition, to have been thickly peopled by a vigorous race; nor, on
looking at those wonderful figured tombstones at Athens, can I
imagine that the healthy and powerful people represented upon
them could have ever passed through the anaemic and splenomegalous
infancy (to coin a word) caused by widespread malaria. Well, I
venture only to suggest the hypothesis, and must leave it to scholars
for confirmation or rejection. Of one thing I am confident, that
causes such as malaria, dysentery, and intestinal entozoa must have
modified history to a much greater extent than Ave conceive. Our
historians and economists do not seem even to have considered the
matter. It is true that they speak of epidemic diseases, but the
iiideniic diseases are really those of the greatest importance. :::

"The whole life of Greece must suffer from this weight, which
crushes its rural energies. Where the children suffer so much, how
can the country create that fresh blood which keeps a nation }^oung?
But for a hamlet here and there, those famous valleys are deserted.
I -aw from a spin- of Ilelikon the sun setting upon Parnassus, Apollo
-inking, a- he was wont to do. towards his own fane at Delphi, and
Hood of light over the great Kopaik Plain. But it seemed

38 LOSS THROUGH INSECTS THAT CARRY DISEASE.

that he was the only inhabitant of it. There was nothing there.
•Who." said a rich Greek to me, 'would think of going to live in

Mich a place as that? ' I doubt much whether it is the Turk who
has done all this. I think it is very largely the malaria."

In considering carefully this suggestive argument of Major Ross
docs it not appear to indicate the tremendous influence that the
prevalence of endemic disease must exert upon the progress of mod-
ern nation.-, and doe- it not bring the thought that those nation- that
are most advanced in sanitary science and preventive medicine will,
other things being equal, assume the lead in the world's work ( Who
can estimate the influence of the sanitary laws of the Hebrew scrip-
tures upon the extraordinary persistence of that race through cen-
turies of European oppression — centuries full of plague years and
of terrible mortality from preventable disease I And what more
striking example can be advanced of the effect of an enlightened
and scientifically careful attention to the most recent advances of
preventive medicine upon the progress of nations than the mortality
-latistics of the Japanese armies in the recent Russo-Japane-e war as
compared with the corresponding statistics for the Briti>h army
during the Boer war immediately preceding, or for the American
Army during the Spanish war at a somewhat earlier date?

The consideration of these elements of national progress ha- been
neglected by historians, but they are nevertheless of deep-reaching
importance and must attract immediate attention in this age of
advanced civilization. The world has entered the historical age
when national greatness and national decay will he based on physical
rather than moral conditions, and it is vitally incumbent upon na-
tions to use eveiy possible effort and every possible means to check
physical deterioration.

INDEX

L»age.

Abattoirs, regulations to avoid house dies 32
Anopheles mosquitoes (see also Mosquitoes, malaria).

disseminators of malaria 7

suppression In Panama 22

Ash pits containing fermenting material, breeding places of bouse flj :;i

Bacillus icteroides, no1 proven to be causative germ of yellow fever r.>

Bacteria From flies, census 29 •';<»

in milk, sources 28 30

Bedbug, a carrier of disease 7

Bedding, old, In ash pits, breeding place of house fly ;;i

Bubonic plague, conveyance by fleas 7

Cafe's, regulation to avoid house flies :;:;

Carcasses of animals, breeding places of house fly 32

Cholera, Asiatic, carriage by house tly 7,27,34

infantum, carriage by house fly up

morbus, carriage by house fly :;i

Culex fas, -in ins Stegomyia calopus 19

Deaths from malaria in United States 9 LO

typhoid fever iu concentration camps, U. s. Army i'l 25

yellow fever m United Slates is. :;i

Disease, endemic, as affecting progress of nations 36 38

Diseases, intestinal, dissemination by house fly 7

Dysentery, summer, carriage by house fly 27,34

tropical, carriage by house fly 27,34

Endemic disease as affecting progress of nations 36 38

Excrement, human, breeding place of house fly 31

Eye diseases, carriage hy house fly 34

Fermenting animal and vegetable material, breeding places of house fly__ ' 5 1 — : 5 12

Filariasis, transmission by a mosquito 7

Pleas, conveyors of bubonic plague 7

Flies, biting, carriers of sleeping sickness 7

Fly. house, breeding places 31-32

disseminator of cholera, Asiatic 7,27. 34

infantum 29

morbus 34

dysentery, summer 27,34

tropical 27

eye diseases 34

intestinal diseases 7,27-28

purulent ophthalmia 7

typhoid fever 7

tuberculosis 7, 28, 34

legislation 32-36

life history 31

relation to typhoid fever 23 27

suppression feasible and all-important 30

manure, name for house fly

typhoid, name for house fly 23

Garbage, breeding place of house fly 32

collection to avoid house flies 32

Hippelates flies, carriers of pink eye 7

Hog hairs, refuse, breeding place of house fly 32

Hops, spent, breeding place of house fly .'M

[nsects affecting health, publications by Bureau of Entomology

Lunch rooms, regulation, to avoid house flies .'!.*'.

Malaria, deaths in United States '.> L0

dissemination by mosquitoes 7,8 17

eradication ;it [smailia, Sue/, Canal l<; 17

in Greece— 36 38

39

40 LOSS THBOUGH ENSECT6 THAT CARRY DISEASE.

Page.

Miliaria, in Italy, loss therefrom 11-12

.Mauritius 11

Reunion 11

United states, history 0

loss iii United states 9 n

Italy 11-12

mosquitoes. (Sec Anopheles mosquitoes and Mosquito, malaria, i

prevention 14_17

relation to agriculture and other industries of the South 13-14

suppression in Havana 17

Panama 21-2:;

Selangor, Federated Malay States. 15-16

Manure, disposal, to avoid DOUSe Hies 32 33

horse, breeding place of house fly :;i

rabbit, in ash piis. breeding place of house fly

Markets, regulation, to avoid house flies :;:;

Milk, sources of bacteria therein 2^ 30

Mosquito, disseminator of filariasis 7

malaria 7

yellow fever 7

malaria (see also Anopheles mosquitoes).

suppression measures 15-17

yellow fever, suppression measures 19 23

Mosquitoes, losses in general which they occasion 8

through malaria which they occasion 8 IT

yellow fever which they occasion IT 21

suppression in Panama 21-23

Nations, endemic disease as affecting progress 36-38

Ophthalmia, purulent, carriage by house fly T

Taper, old, breeding place of house fly 31

Pink eye. carriage by Hippelates flies 7

Plague, bubonic. (See Bubonic plague.)

Poultry-house bedding, breeding place of house fly 32

Progress of nations as affected by endemic disease 36-38

Rags, old. in ash pits, breeding place of house fly 31

Restaurants, regulation, to avoid house flies .".:;

Sanitation, rural, necessity for government support 35

Slaughtered cattle paunches, breeding places of house fly .".2

Sleeping sickness, carriage by biting flies 7

" spotted fever," carriage by tick 7

Stable inspection against house flies, probable cost 33-34

Stables, regulation, to avoid house flies 32-33

Stegomyia calopus (see also Mosquito, yellow fever).

disseminator of yellow fever 7. 19, 20

Stores, regulation, to avoid house flies

Straw, old, in ash pits, breeding place of house fly 31

Tallow vats, breeding places of house fly 32

Tick, carrier of "spotted fever" 7

Tuberculosis, dissemination by house fly 7,28,34

Typhoid fever, a "National Reproach" 36

dissemination by house fly 7,23-27,34

in concentration camps, U. S. Army 2

loss in United States 30

Vegetable refuse, fermenting, breeding place of house fly 32

Yellow fever, cause, history of investigation 19

deaths in New Orleans 21

United Staves is

dissemination by mosquito 7

history in America 17-18

loss in United states IS

mosquito. (See Mosquito, yellow fever.)

suppression in Ha\ana and New Orleans 19-21

Panama 21-23

O