British Museum (Natural Histor;
Guide to the specimens

BRITISH MUSEUM (NATURAL HISTORY)
Special Guide No. 7

GUIDE 10 THE SPECIMENS
AND ENLARGED MODELS O}^

INSECTS

AND TICKS EXHIBITED IN THE

CENTRAL HALL

ILLUSTRATING THEIR IMPORTANCE
IN THE SPREAD OF

DISEASE

o iji.

LONDON
PRINTED BY ORDER OF THE TRUSTEES
» OF THE BRITISH MUSEUM

191 6

[Price Sixpence]

.

PRESENTED

The Trustees

i.
1

THE BRITISH MUSEUM.

BRITISH MUSEUM (NATURAL HISTORY)

\ < *

Special Guide: No. 7.-

GUIDE TO THE SPECIMENS
AND ENLARGED MODELS OF

INSECTS

AND TICKS EXHIBITED IN THE

CENTRAL HALL

ILLUSTRATING THEIR IMPORTANCE
IN THE SPREAD OF

DISEASE

LONDON
PRINTED BY ORDER OF THE TRUSTEES

OF THE BRITISH MUSEUM

*

1916

[All rights reserved)

lONDOX :
PRINTED BY WILLIAM CLOWES AND SONS, LIMITED,
DUKE STREET, STAMFORD STREET, S.E., AND GREAT WIND3IILL STREET,

^1

C

PREFACE.

The method of explaining to visitors the general appearance and
the details of the external features of insects by means of models
on a large scale, rather than by the more customary drawings,
was first adopted by Sir E. Ray Lankester, Director of the
Museum, in the year 1900. The earliest models were those of two
mosquitoes and a tsetse-fly. After Sir Ray Lankester's retirement
in December 1907, the method was followed up by the preparation
of a model of a flea (presented by the Entomological Research
Committee) ; more recently, models of a house-fly and a tick
have been added. During the present year the series of disease-
spreading insects and ticks has been further increased by placing
on view a collection of specimens and models of tsetse-flies,
tabanid flies, mosquitoes and ticks ; this collection was prepared,
on behalf of the Exhibitions Branch of the Board of Trade, in
1913, under the direction of Mr. E. E. Austen, Assistant in the
Department of Entomology, and was showm in the " Tropical
Diseases " Section of the International Exhibition at Ghent in
the summer of that year. The models have been kindly lent to
the Museum by the Board.

Only those insects and ticks that are of importance in the
spread of disease have been selected for exhibition in the middle
of the Central Hall ; the general series of insects and ticks is
to be found in the Arthropod Gallery, in the West Wing of the
Museum ; the collection of insects injurious to crops is exhibited
in the North Hall.

The large models shown in the Hall w^ere constructed
under the supervision of expert entomologists by Mrs. E. D.
Blackman and Miss Grace Edwards, and so far as is possible
they are correct in the smallest details.

The present guide-book is to a large extent a compilation, made
by Dr. W. G. Ridewood, of the exhibited labels that accompany
the insects and the models.

The acknowledgments of the Trustees are due to Drs. Castellani
and Chalmers for permission to use the figures of the house-fly,
bed-bug and tick given in their Manual of Tropical Medicine.

L. FLETCHER,

Director.
British ^Iuseum (Natural History), -
December, 1915.

TABLE OF CONTENTS.

PAGE

Inteoduction ........ 7

Mosquitoes and Malakia ...... 8

Mosquitoes and Yellow Fevee . . . . .18

Mosquitoes and Filaeiasis ...... 20

Fishes that Feed upon the Laevae of Mosquitoes . 21

Tsetse-Flies and Teypanosomiasis .... 22

Tabanid Flies and " Calabae Swellings " . . . 26

House-Flies and Intestinal Diseases .... 27

Sheep Bot-Fly ........ 31

Fleas and Plague ....... 32

Bed-Bugs and Disease ...... 37

Lice and Disease ....... 38

Ticks and Disease ....... 40

LIST OF ILLUSTRATIONS.

FIG. c PAGE

1. — Organisms of Malaria ...... 11

2. — Eesting Attitudes of Anopheline and Culicine Mosquitoes 13

3. — A Mosquito, Anopheles maculipennis ; Carrier of Malaria 15

4. — A Mosquito, Stegomyia fasciata ; Carrier of Yellow Fever 19

5. — Organisms of Sleeping Sickness .... 23

6. — A Tsetse-Fly, Glossina palixtUs ; Carrier of Sleeping

Sickness . . . , . . . . . 25

7.- — Organisms of Typhoid Fever ..... 28

8. — -House-Fly, Musca domestica ; Carrier of Various

Intestinal Diseases ...... 29

9. — ^A Eat-Flea, Xcnopsylla cheopis ; Carrier of Plague . 33

10. — Organisms of Plague ...... 34

11. — Bed-Bug, Clinocoris lectularius .... 37

12. — ^Clothes-Louse, Pediculus humayius ; Carrier of Typhus

Fever 39

13. — Organisms of Eelapsing Fever . . '. . .41

14.— A Tick, OrnitJiodows moubafa ; Carrier of African

Eelapsing Fever ...... 42

INSECTS AND TICKS

AND THEIE IMPOETANCE IN THE

SPREAD OE DISEASE.

INTRODUCTION.

The entrance to the museum is at the South end of the Central
Hall, and the main staircase at the North end ; the side of the
Hall to the right of the visitor as he enters is the East. The
Bays or Eecesses arovmd the Hall are designated by numerals,
painted below the end windows. On the East side the most
southern l^ay, that near the statue of Prof. Huxley, is No. X ; on
the West side the southern liay, with the bust of Sir William
Flower against the arch, is No. I.

The grouping of the objects in the following pages is one based
upon the systematic position of the insects themselves, and not
according to the sequence of the show-cases in which they are
exhibited. This arrangement has the effect of causing a visitor
who reads the pages consecutively to walk away from a case before
exhausting it, and to return to the case later in order to see other
insects contained in it ; but the method has the advantage of
preventing any mental confusion that might possibly arise from a
study of both mosquitoes and tsetse-flies in one show-case, followed
by an examination of mosquitoes and tsetse-flies in other cases.
It is preferable to complete the examination of all the mosquitoes
exhibited, and then to commence the study of the tsetse-flies, and
to pass on subsequently to other groups of insects in their turn.

While most of the specimens are displayed in ordinary
museum show-cases, a few, mainly fleas, are shown under two
microscopes of special construction which permits of the
examination of several specimens in succession. The slides are

8 Guide to Insccis and Ticks

attached to a drum, which rotates upon its axis liy means of a
milled wheel operated by the visitor. Another milled wheel at the
side of the instrument enables the visitor to adjust the focus to
suit his own e^'esight. The microscope on the West side of the
Hall carries twelve slides, that on the East live slides.

MOSQUITOES AND MALAlilA.

Malaria is a disease of man caused l)y minute parasites that
invade the red corpuscles of the blood. The parasites belong to a
very low grade of animals, and are included in the division of the
Protozoa known as Hamosporidia.

Formerly malaria, commonly known in this country as ague,
was thought to be contracted by breathing the air of marshy
districts, but it is now proved that it is due to these parasites,
transmitted from man to man by the bite of certain kinds of
mosquitoes or gnats. Although there are many hundreds of
species of mosquitoes, it is only those belonging to the genus
Anopheles, and only certain species of that genus, that are capable
of conveying malarial parasites to man. The parasite multiplies
not only in the human blood, but also in the walls of the stomach
of the mosquito.

Various forms of malaria are distinguished by medical men
according to the frequency of the recurrence of fever and other
symptoms, as tertian, quartan, etc. Each is due to a distinct
species of parasite, though the visible differences between the
species are very slight. The parasite of pernicious or aestivo-
autumnal fever is known under the name of Plasmodium falci-
parum Welch ( = Laverania malariae Grassi and Feletti) ; that
of tertian fever is Plasmodium vivax Grassi and Feletti, and
that of quartan fever, Plasmodium vialariae Laveran. Parasites
similar to these frequently occur in the blood of other mammals,
more especially in that of apes and monkeys, and also in the
blood of birds of many species.

Malaria is now almost extinct in Northern Europe, but in
many parts of the tropics it is still one of the commonest of
diseases. At the beginning of the present century, however,
practical measures for the extermination of mosquitoes were
introduced in many parts of the tropics, and the rigid enforcement

that spread Disease. 9

of these precaufcious has frequently heen followed l^y marked
diminution in the prevalence of malaria, or even its total or almost
complete disappearance.

In a table-case that stands at the entrance to Bay X, near the
statue of Prof. Huxley, are shown two greatly enlarged models
(x 28) of one of the malaria-carrying species of mosquito,
AnopheJcs maculipennis Mg., together with an actual specimen, for
the purpose of giving a correct impression of the real size of the
insect. The model on the left hand panel shows the attitude of
the mosquito w^hen flying (fig. 3, p. 15) ; that on the right hand
panel shows its attitude when at rest (fig. 2, a). Both of the
models represent the female insect, for in the species of mosquito'
that suck blood the blood-sucking habit is confined to the female.
In the case of an infected mosquito capable of communicating the
disease, the young forms of the malarial parasite escape into the
blood with the secretion of the salivary glands, which is introduced
into the w^ound at the time of the bite.

In the middle part of this case is shown a series of greatly
enlarged models ( x 6,000) illustrating the complete life-cycle of
the parasite of pernicious or aestivo-autumnal malarial fever,
Plasmodium falciparum, some stages of which are passed through
in the blood of man, others in the body of the mosquito. The
models are numbered consecutively, and are explained in the
following terms : —

^■o

1. — A malarial germ or sporozoite (fig. 1, a), as introduced
into the blood of man by the proboscis of a female anopheline
mosquito.

2. — The sporozoite penetrates into a red blood-corpuscle, and
becomes rounded off into a compact mass (fig. 1, h).

3.- — The parasite enlarges and a vacuole appears within it.
Signet ring stage.

4. — The vacuole disappears, and the parasite enlarges and
emits blunt processes. Amoebula stage.

5. — The nucleus multiphes, and the pigment granules increase
in number (fig. 1, c).

6. — The nuclei arrange themselves at the periphery. Rosette
stage.

7. — The daughter-individuals (merozoites) separate from the
central non -nucleate protoplasm (fig. 1, d).

lo Gtiide to Insects and Ticks

8. — The mei'ozoites become free in the blood-plasma by the
disintegration of the red corpuscle (lig. 1, e). Each merozoite
invades a red blood-corpuscle, and develops into amoebula, rosette,
and further merozoites, as explained in the preceding models.

9, 10. — After several cycles of amoebula, rosette, and
merozoites, a merozoite on entering a red corpuscle grows into a
sexual form which may be crescentic (fig. 1,/).

11. — The crescent increases at the expense of the corpuscle,
and male crescents become distinguishable from female crescents,
as explained in models 12 and 15. The crescents undergo no
further change in human blood, but when blood containing
crescents is sucked by a female anopheline mosquito, the crescents
undergo development.

12. — The male crescent (fig. 1, _r/) is shorter and more rounded
than the female crescent. It has clearer protoplasm and a larger
nucleus, and the pigment granules are more scattered.

13, 14. — The male crescent becomes spherical and the nucleus
multiphes.

15. — The female crescent (fig. 1, It) has denser protoplasm and
a smaller nucleus than the male, and the pigment granules are in
the middle part of the crescent.

16, 17, 18.— The female crescent becomes spherical, and, after
extruding two small cells (? polar bodies) in succession, becomes
the macrogamete or ovum, and is ready for fertilisation.

19. — The male sphere shoots out four, five or six slender pro-
cesses (microgametes or sperms) consisting mainly of nuclear
material (fig. 1, i). The remainder of the sphere plays no further
part in the life-history.

20. — A microgamete is attracted by, and enters into an ovum
(fig- 1. ])■

Fig. 1. — Life Histoey of the Organism op Pernicious Malaria.

«, malarial germ or sporozoite, as introduced into the blood of man by a female
anopheline mosquito at the time when it is sucking blood ; 6, sporozoite after entry into a
blood-corpuscle of man ; c, growth of the sporozoite into an amoebula ; (7, division of the
amoebula to form merozoites ; e, liberated merozoites ; /, growth of a merozoite into a
crescent; f/, free male crescent; h, free female crescent; i, male cell with projections,
which lengthen and are set free as sperms ; j, fertilisation of an ovum by a sperm ; fc, ferti-
lised egg as an active motile vermicule ; I, sphere formed from the enlarged vermicule, after
this has bored through the stomach-wall of the mosquito ; m, portion of the sphere or cyst
at a late stage of development, containing countless needle-shaped spores, which, when the
cyst bursts, escape as sporozoites into the organs of the mosquito's body, and pass through
the salivary glands into the proboscis, and so infect a man bitten (i.e. pricked) by the
mosquito, a-l are enlarged 3, .500 diameters ; m is drawn to a smaller scale of magnification.

■*'.:

■^,\\

^m

II

■m.!^

Fig. 1.

12 Guide to Insects and Ticks

21.- — On entry into tlie ovum the microgamete becomes a
nucleus. The two nuclei unite, and the fertilised ovum or zygote
becomes motile.

22. — The zygote elongates and bores its way through the
wall of the stomach of the mosquito. Ookinete or vermicule
stage (fig. 1, A).

23. — On the outer surface of the stomach of the mosquito the
ookinete becomes spherical, and increases greatly in size, the
nucleus multiplying at a rapid rate. A protective covering or cyst
forms around the sphere. (Only one half of the sphere is shown.)

24. — The sphere divides up into sporoblasts, each being a small
cell with a single nucleus (fig. 1, /). (Only one half of the sphere
is shown.)

25. — In each sporoblast the nucleus divides into a great number
of small nuclei, and the surface of the sporoblast growls out into a
great number of pointed processes, into each of wdiicli a nucleus
enters. These nucleated processes elongate further, and separate
from the central part of the sporoblast, and Ijecome motile spores
or sporozoites (fig. 1, m). (The model shows only one half of the
cyst.) On the bursting of the cyst the sporozoites escape into the
various organs of the body of the mosquito.

26. — Free motile sporozoites. Such of these as reach the
salivary glands pass through the ducts of the glands into the
proboscis, and when next the mosquito pricks the skin of a man
for the purpose of sucking blood, some of them are left in his
body, and develop in the red corpuscles in the manner explained
by the models in the upper part of the series.

In the large table-case that stands in Bay YI, on the East
side of the main staircase, are shown models of the malarial
parasite somewhat similar to those just referred to, but of earlier
construction. They illustrate the phases in the life-history of the
organism so far as they were known at the time when the models
were made (1901) ; the more recent series, in the case near Bay X,
embodies the results of investigations up to May 1913.

On the sloping panels in this table- case in Bay YI are
mounted enlarged models ( x 28) of one of the malaria-carrying
mosquitoes, Anopheles macHli'pomis Mg., similar to the two models
already seen in the other case (Bay X). Side by side with these
are shown, for purposes of comparison, enlarged models of another

that spread Disease.

13

gnat or mosquito, Culcx pqnens Linn., an insect which, although
it can make itself unpleasant, does not transmit malaria.

The models on the South side of the case represent the insects
in the resting attitude, and illustnite a characteristic diti'erence
between anopheline and culicine mosquitoes. The former have
the proboscis, thorax and abdomen set in a straight line, whereas
culicine mosquitoes, when viewed from the side, have a hump-
backed appearance, owing to an arching of the thorax, so that the
line of the proboscis is set at an angle to the axis of the hinder
part of the body. When resting on a wall or other flat surface, a

Fig. 2. — Anopheline and^Culicine Mosquitoes in Resting Attitude.

A. Amrpheles maculipennig, female, X 4.

B. Ctdex 2)ipieii-f, female, X i-

culicine keeps the abdomen more or less parallel to the surface,
whereas an anopheline slopes the abdomen away (fig. 2).
Anophelines nearly always have spots on the wing. In both
sexes of anopheline mosquitoes the maxillary palps are as long
as the proboscis, and those of the male are clubbed at the tip.
In culicines the palps of the female are much shorter than the
proboscis, and those of the male are a little longer than the
proboscis, and usually not clubbed at the tip — in mosquitoes the male
can be readily distinguished from the female l)y the more plumose
or fluffy antennae. In culicines the abdomen is completely clothed
with scales like those on a moth's wnng, some of the scales forming

14 Guide to Insects a? id Ticks

in many species conspicuous white transverse bands at tlie base
of each segment ; in anophelines the abdomen is without distinct
scales, and hence without well-defined markings.

In the lower part of the South side of the case are displayed a
series of models, enlarged 28 diameters, like those of the adult
insects, showing the appearance of the eggs, the larvae and the
pupae of Culcx and Anopheles. The black threads stretched
horizontally represent the surface of the water. The eggs of
mosquitoes float upon the surface, and the larvae and pupae move
about in the water, breathing by means of their air-tubes, which
now and again are caused to project very slightly above the
surface. The eggs of Culex are massed into a raft composed
of two or three hundred eggs with their more pointed ends
directed upwards. The eggs of Anopheles fl.oat singly or in
small groups easily scattered by the wind, and are disposed on
their sides instead of standing erect upon the water. Each egg
has a pair of small air spaces, as shown in the upper model ( x 65)
at the right hand end of the series, above the group of eggs
(X 28).

The characteristic attitude of the larva of the culicine mosquito
is one in which the head is downmost, the body slightly inclined
to the vertical, and the extremity of the air tube at the hind end
of the body just touching the surface of the water. The larva of
the anopheline mosquito rests horizontally just below the surface
of the water ; the air-tube at the hind end of the body is very short,
and just level with the surface. When feeding, the larva twists
its head half-way round, and laps the surface of the water for
minute vegetable organisms. Both culicine and anopheline larvae
when alarmed strike down into the water with a rapid jerking
movement.

■ The pupae of the culicine and anopheline mosquitoes do not
differ greatly. In each case the pupa rests with the two horn-like
air-tubes on the thorax at the surface of the water, but it can swim
rapidly by a jerking movement of the abdomen, which is provided
at its extremity with two transparent paddle-like organs.

In the lower part of the North side of the case are enlarged
drawings of the mouth-parts of the two species of gnat or mosquito
illustrated, the culicine, Culex pipiens, and the anopheline,
Anopheles macuUpennis. The prol)oscis of mosquitoes consists of
a long, channelled labium and six piercing instruments contained

that spread Disease.

15

within it— a labrum, a bypopharynx, a pair of maxillae, and a
pair of mandibles. Tbe labrum of mosquitoes is generally
long, slender, and pointed, and grooved beneath for the re-
ception of the bypopharynx, which lies immediately below,
and has its apex more or less wrapped round by the inflected
margins of the labrum. The two maxillae are long, and each
tapers gradually to the apex, which is provided with fine teeth.
The two mandibles are of the same length as the maxillae, and
their tips partially embrace the apices of the maxillae. All these

Fig. 3. — A Mosquito that spreads Malaria,
Anopheles maczdipennis, female, X 4.

parts when at rest lie concealed in the labium, which is deeply
channelled for their reception, and is furnished at its extremity
with two fleshy lobes, the labella. The labium does not enter
the skin of the animal attacked, but bends back beneath the
body of the insect, the labella acting as guides to support the
piercing organs.

In male gnats the mandibles are absent, and the maxillae are
very short, and cannot be used as piercing instruments. The
maxillary palps of the male Cnlex are as long as the proboscis.

1 6 Guide to Insects and Ticks

and are somewhat brush-like, but in the female they are very
short and simple.

In Ano'plides the maxillary palps are long in both sexes. In
the male the apical joint is thickened and hairy, and diverges from
the proboscis, while in the female the palps are straight and lie
close to the sides of the proboscis for their whole length.

The first three drawings exhibited show the head, as seen from
above, of the female Anoplieles macuUpennis, and the female and
male Cidex pi-incns. In order that the six piercing instruments
may be clearly seen, they are represented as dislodged from the
gutter-like labium, within which they are concealed in the living
insect. The next two drawings show the forms of the extremities
of the labrum, hypopharynx, maxillae and mandibles of female
specimens of Anopheles macitlipennis and Culex pipiens. The
labrum is viewed from beneath, the other parts from above. The
sixth drawing is that of a cross-section through the proboscis of a
female Culex pipiens, showing the relative positions of the piercing
organs when at rest ; and the last is a diagram of the terminal
portion of the labium of the same insect showing the form of the
labella as viewed from above and from below.

On the sloping panel above the drawings are two diagrammatic
models of the head of a female culicine mosquito or gnat, viewed
from the side. The upper model shows the proboscis as it appears
when beginning to pierce, the lower one shows the disposition of
the parts when the lancets have penetrated a short distance into
the skin. The labium does not enter the skin, but loops down-
ward and backward beneath the body of the gnat, so that the six
lancets are no longer enclosed in its gutter-like groove ; the
apposed labella continue to surround the lancets, and slide along
them from point to base as the skin is penetrated.

For comparison with the culicine and anopheliue mosquitoes
there is shown, at the East end of the case, a model, enlarged
28 diametei'S like those of the mosquitoes, of a common midge,
Chironomus plumosus Linn., a harmless insect, not to be mistaken
for a mosquito or gnat. The model represents the female midge ;
the differences between the heads of the two sexes are illustrated
in the two drawings above the model. An actual specimen of a
male midge is also exhibited. Cliiroitomtis plumosus is one of
the largest of the midges, and occurs in swarms in the air from
April to August. The larger midges may be distinguished from

tJiat spread Disease. i 7

mosquitoes or gnats by the absence of the long proboscis, by the
length of the front legs, and by their habit of resting with the front
legs raised — in mosquitoes it is the hind legs that are raised when
the insect is resting (see the models on the South side of the case).

In the lower part of this (East) end of the case is a model of
the larva of Cliironomus ijlumosus, a red, caterpillar-like, aquatic
form sometimes termed a blood-worm. The larva lives in a
tunnel which it makes at the bottom of some ditch, pool or rain-
water butt. It breathes by means of four filaments, or blood-gills,
at the hind end of the body, on the last segment but one, and
four thicker processes on the last segment. Crawling movements
are effected by a pair of foot-like organs beneath the head, and a
pair at the hind end of the bod}'. At night, and sometimes by
day, the larva swims freely, jerking the body suddenly to the right
and to the left in such a manner as to present the appearance of a
figure of eight. When in its tunnel the larva imparts to its body
an undulating movement, thus creating a flow of fresh water
through the tunnel.

The series is completed by a model, enlarged 28 times linear
like that of the larva and adult, of the pupa of the midge
Chironomus phoiiosus. While still within its tunnel the larva
turns into a pupa, and remains there, lying on its side and
imparting an undulating movement to the body. The pupa
breathes by means of a pair of tufted tracheal gills on the thorax.
When approaching the stage of the imago or perfect insect, it
leaves the tunnel and swims to the surface of the water ; the skin
splits along the back, and the winged midge emerges, and flies
away almost immediately.

In the table-case that stands at the entrance to Bay I, near
the bust of Sir William Flower, are shown dipterous insects of
various kinds, tsetse-flies, tabanids and mosquitoes, selected
because of their capacity for spreading diseases, and mounted
together with examples of their near relatives, which, so far as our
present knowledge goes, are harmless. Since almost all insects
associated with maladies are of small size, the specimens are
mounted close to the glass of the case, in order to enable visitors
to see as much as possible of their general appearance and
external characters. The mosquitoes of this series are on the
West side of the case, away from the middle of the Hall.
Examples are shown of both males and females, and the

c

1 8 Guide to Insects and Ticks

geograp]iical distiil)ution of each of the species of which examples
are shown is explained ))y means of a small map, with the regions
in which the insect is found marked in red.

The following species of mosquitoes are exhihited, all known
to convey the parasites of malaria from man to man, and thus to
disseminate the disease : — AnoijJieles viacuUpennis Mg. (fig. 3,
p. 15), A. bifitrcatus Linn., Europe and North America — A.
(Myzoviyia) listoni Listen, A. (il/.) culicifacies Giles, A. (Myzo-
rhynchus) harhirostris v.d. Wulp, A. [M.) sincnsu Wied., A. Nco-
cellia stepliensi Listen, A. (N.) toillmori James, A. [Nyssorliynclins)
tlieohaldi Giles, A. [N .) fuliqinosits Giles, Asia — A. (N.) maculi'imlpis
Giles, Asia and Africa — A. [Myzomyia) funestus Giles, A. (Pyreto-
phorus) costalis Loew, A. [Myzorhyndius) maiiritiamis Grandprt^,
A. (il/.) ixtludis Theoh., A. {CeUia) ijJiaroensis Theob., Africa —
A. [Nyssorhynclnis) annulipes Walker, Australia — A. [Myzomyia)
lutzi Theob., A. (Cellia) albimanus Wied., .4. (C.) argyrotarsis
Eob.-Desv., South America.

Disregarding for the present the mosquitoes that spread yellow
fever and filariasis, these being dealt with in this guide-book
under subsequent headings, the visitor arrives at a selection of
" apparently harmless " mosquitoes — those which do not, or at all
events are not known to, disseminate disease, namely : — Anopheles
[Cliristya) implcxus Theob., Mcgarhmus separatus Arrib., Toxo-
rhynchites speciosus Skuse, Janthinosoma sayi Dyar and Knab,
Stegomyia scutellaris Walk., S. apicoargentea Theob., Dcsvoidya
ohturhans Walk., Oclilcrotatus cuviminsi Theob., 0. vittigcr Skuse,
Tacniorluinchus aurites Theob., Acdcoinyia catasticta Knab.,
TJteohaldia spatliipalpis Eond., Culcx concolor Eob.-Desv., C.
annuUrostris Skuse, G. tigripcs Grandpr6," var. fiiscus Theob.,
Mimomyia j)lumosa Theob., Harpagomyia genurosiris Leic,
Eretmopodites clirysogastcr Graham, Wyeomyia communis Leic,
Sabethcs cy emeus Fabr.

MOSQUITOES AND YELLOW FEVER.

So far as is at present known, yellow fever is disseminated
solely by the mosquito Stegomyiet feisciata Fabr., sometimes called
the tiger-mosquito (fig. 4). As in all other mosquitoes that suck
blood, the blood-sucking habit is confined to the female. The
virus of the disease is introduced into the blood by the proboscis

that spread Disease. 19

of the infected insect at the time of the l)ite. Yellow fever is
primarily a disease of the West Indies and the East Coast of
Mexico, but it has been spread by shipping to many other parts of
the world.

The causal agent of yellow fever is not known with certainty,
although the disease has been attributed to an extremely minute
protozoon found in the blood. That it is a living organism and
not a chemical substance is evident from the fact that some time
(about three days) elapses between the bite of the mosquito and
the onset of the febrile symptoms, and a mosquito is not capable

Fig. 4.— A Mosquito that spreads Yellow Fever,
Stegomyia fasciata, female, X 4.

of infecting until about twelve days after it has sucked the blood
of a yellow-fever patient. These intervals of time are clearly
periods during which an organism is undergoing some parts of its
developmental process.

Specimens of Stegomyia fasciata Fabr. are shown in the series
of mosquitoes on the West side of the table-case that stands
at the entrance of Bay I. The species occurs in tropical and
subtropical regions throughout the world, and is also found in
Southern Europe and other countries bordering the Mediterranean
Sea, and in the southern parts of the United States of America.

c 2

20 Guide to Insects and Ticks

In a small case standing between the statue of Sir Eicharcl
Owen and the bust of Sir WiUiam Flower in Bay I is shown a
model of the yellow-fever mosquito, Steyuniijia fasciata, enlarged
28 diameters so as to be comparal)le with the enlarged models of
Cnlcx pipicns and Anoplteles macuUpciuiis shown elsewhere. On the
back of the panel is a map showing the distribution of the species.

In general attitude a Stegomyia resembles a Cidex rather than
an Anopheles (fig. 2, p. 13) ; the thorax is arched, giving a hump-
backed appearance to the body. The thorax of Ste{iomi/ia fasciata
is black, with a conspicuous lyre-shaped wihte mark on the back ;
the tarsi are black, ringed with white at the base of each joint.
In Culex pipiens the thorax is brown, without distinct markings,
and the tarsi are black.

Essentially a domestic species, Stegomyia fasciata is always
found in the vicinity of human habitations. Its wide distribution
is believed to be largely due to the insect, in the egg, larval and
adult stages, having been carried about the world in ships. It
breeds not only in water-barrels and cisterns, wells, and the bilges
of ships, but also frequently in puddles and pools of clean, foul,
or brackish water, and even in a small quantity of rain-water
standing in an old sardine-tin or broken bottle. The eggs are
remarkably resistant, and are not necessarily rendered incapable
of development if the water on which they are laid happens to
dry up. In one instance some eggs of Stegomyia that had been
kept in a dry state for six months gave rise to living larvae after
being placed in water.

MOSQUITOES AND FILARIASIS.

Pilariasis is a general term applied to diseases caused by thin
thread- worms of the genus Filaria. Elephantiasis, one of these
diseases, is due to Filaria bancrofti Cobbold, the embryos or larvae
of which are carried from man to man by certain mosquitoes, particu-
larly Ciilcx fatigans Wied. Mosquitoes are also responsible for the
spread of some other forms of filariasis, and it is interesting to note
that some species of mosquito spread both malaria and filariasis.

In the table-case that stands at the entrance of Bay I are
shown the following mosquitoes known to be instrumental in the
spread of various forms of filariasis : — Anopheles maculipennis Mg.
(fig. 3, p. 15), A. {Myzorhynchus) sinensis Wied, var. nigerrimus

that spread Disease. 21

Giles, and var. 7ninutus Theob., A. [Myzomyia) rossi Giles, A.
(21/.) fiuiestus Giles, .-1. {Pyretophorus) costalis Loew, A. (Cellia)
argyrotarsis Eob.-Desv., Culex fatigans Wied., Stcgomyia pscu-
(loscntcUaris Theob., JSIansonioidcs uniformis Theob., Taenio-
rhynchus titUlans Walk,, T. pscudotitillans Theob.

FISHES THAT FEED UPOX THE LARVAE
OF MOSQUITOES.

By reducing the numbers of the larvae, and consequently the
number of mosquitoes, certain fishes are beneficial in their effect,
and lessen the chance of transmission to man of mosquito-borne
diseases.

The five fishes exhibited in the glass vessel of alcohol are
denoted by letters. A is the male, and B the female of a little fish
known as " millions " [Lchistes reticulatus Peters). C is a female
specimen of a "top-minnow" (Gambusia affiiiis Girard). D is a
male, and E a female of Haplochilus pumilus Blgr., a fish without
a popular name.

" Millions " (A and B) occur in fresh and brackish waters of
Venezuela, Guiana, Trinidad, and the Windward Islands. The
correct scientific name is Lebistes reticulatus, but the species has
also been described as Girardinus poeciloides (from Barbados), as
Girardinus guppyi (from Trinidad), and as Poecilia reticulata
(from Venezuela). The females are viviparous ; the males are
smaller than the females, and have ornamental markings, whereas
the females are plain in coloration. " Millions " are very prohfic,
producing a brood every few weeks. They have been exported
into various tropical countries for the purpose of reducing the
numbers of mosquitoes, but those recently introduced into Africa
are said to have been devoured by the frogs.

"Top-minnows" (C) like "Millions," are viviparous, and
belong to the Poeciliine group of the Cyprinodont fishes ; they
inhabit the Mississippi and fresh and brackish waters from Florida
to Texas.

Haplochilus pumihiH occurs in Lake Tanganyika and Lake
Victoria in Central Africa ; it is oviparous, and although it is known
to devour mosquito-larvae but little bas l)een recorded as to its
natural history.

22 Guide to Insects and Ticks

TSETSE-FLIES AND TRYPANOSOMIASIS.

Trypanosomiasis is a general term applied to diseases caused
by species of Trypanosomes, small blood-parasites of an animal
nature, belonging to the division of the Protozoa known as the
Haemoflagellata.

Tsetse-flies are African, blood-sucking, dipterous insects, with
peculiarly modified, piercing mouth-parts. The blood-sucking
habit in tsetse-flies is common to both sexes, whereas in
mosquitoes the females alone suck blood. The virus of the
disease is introduced into the blood by the proboscis of the
infected insect at the time of the bite.

In one of the cases in the middle part of the Hall, near the
statue of Sir Eichard Owen, is shown a large model ( x 28) of one
of the tsetse-flies, Glossina morsitans Westw., which is mainly
responsible for the spread of a deadly disease— nagana — among
domesticated animals. In the blood of African animals, such as
antelopes and buffaloes, there is frequently found a parasite,
TnjiKinosoma brucei Plimmer and Bradford, which apparently
causes little inconvenience to the host, but this, if transferred to
a horse, ox or dog by the piercing proboscis of a tsetse-fly that has
previously fed upon the blood of an infected antelope, gives rise j;o
the nagana or tsetse-fly disease. The fatal disease of man known
as sleeping sickness is spread by the tsetse-flies Glossina palpalis
Eob.-Desv. (fig. 6, p. 25) and G. morsitans Westw. The organisms
causing sleeping sickness are Tnjpanosoma f/ambicusc Dutton (fig. 5)
and T. rliodcsioise Stephens and Fantham, in West and Central
Africa and North-east Ehodesia respectively.

In the same case are shown actual specimens of the tsetse-
flies Glossina morsitans and G. palpalis, and enlarged coloured
drawings ( X 2) of the under and side views of a specimen of
the former species, showing the collapsed and the gorged condition
of the abdomen before and after a meal of blood. Another drawing,
of the natural size, shows how the wings of a tsetse-fly overlap
one another above the abdomen when the insect is at rest. In the
glass vessel are four larvae at difl'erent stages of growth, and a
pupa, of Glossina palpalis. The end of the pupa-case that bears
the two projections is the hind end, as is explained in the enlarged
drawing ( x 12) placed alongside.

Sketches are exhibited of a horse and a dog sufl'ering from

that spread Disease.

23

nagana or tsetse-fly disease. In the horse the onset of an attack
may be detected by the coat staring, and by a watery dischai'ge
from tine eyes and nose. Shortly afterwards there appears a
general swelling of the belly and hind extremities, which fluctuates
from day to day. The animal hangs its head, and there is a
general emaciation, sometimes accompanied by blindness. Death
results from exhaustion; there are no symptoms of pain, and the
appetite continues good till the last. In the dog the disease runs
a rapid course, and is invariably fatal. The chief symptoms are
extreme emaciation, swelling of the extremities, eruption over the
liody with the formation of blebs and pustules containing more or
less purulent matter, and finally milky opacity of the cornea
giving rise to blindness.

Fig. 5. — Organisms of Sleeping Sickness,
Tri/panosoma gambiense, and red blood-corpuscles; X 1,500.

A map of Central and Southern Africa is exhibited, showing
our knowledge of the distribution of the tsetse-flies (Glossina) in
1911, at the time of the issue of Mr. E. E. Austen's " Handbook
of the Tsetse-Flies," pubhshed by the Trustees of the Museum.

Around the lower part of the case are shown enlarged coloured
illustrations ( X 6) of the ten species of tsetse-flies that were
known at the time of the publication of the book in 1911.

Displayed upon the glass shelf in the case are greatly enlarged
transparent models ( x 6,000) of red blood-corpuscles and a form
of trypanosome (T. leicisi Kent) found commonly in the blood
of rats. Trypanosomes are small, elongated, parasitic animals
occurring in the fluid part (plasma) of the l)lood ; they have an
undulating membrane or longitudinal fin which runs along the

24 Guide to Insects and Ticks

body, and is continued forwards into a filament or flagelliim. In
an allied genus, Triipanoplasma, there is a fiagellum at each end of
the body.

Although many forms of trypanosomes are spread from one
vertebrate host to another by tsetse-flies, some are spread by other
blood-sucking invertebrates, such as gnats, fleas, leeches, etc. ; the
trypanosomes that are found in skates and similar fishes, for
instance, are known to be conveyed by marine leeches. In the
case is shown a specimen of an African fly, Hippohosca rufipes von
Olfers, allied to the forest-fly of Britain, Hippohosca equina Linn,
(see enlarged photograph ( x 6) below the glass plate), and respon-
sible for the spread of the blood-parasite Trypanosoma thcileri
Bruce, causing gall-sickness among cattle in the Transvaal.

Other trypanosomes of interest in connection with disease are
T. cquinum Vosges, causing " mal de caderas " of horses in South
America, T. evansi Steel, causing surra of horses and cattle in
India, and T. cquiperdum Doflein, causing dourine in horses in the
countries around the Mediterranean Sea, and T. cruzi Chagas, the
cause of the fatal disease barbeiro in man, particularly children,
in South America, and conveyed by a hemipterous insect or bug,
Lamus mcgistus Burmeister, more than an inch in length.

In the large case that stands at the entrance to Bay I, near
the bust of Sir William Flower, is shown a selection of tsetse-
flies, together with enlarged coloured drawings ( x 6), and maps
showing the distribution of the several species. Tsetse-flies may
be said to be African insects, although one species is met with in
south-western Arabia, and in former times tsetse-flies existed in
North America.

The first examples shown are those of Glossina palpalis
Eob.-Desv. (fig. 6) of West and Central Africa, the principal
disseminator of Trjipanosoma (lamhicnsc Dutton, causing sleeping
sickness in man. These tsetse-flies exist only in shady places,
and haunt the margins of lakes and water-courses where the
banks are covered with vegetation. Specimens are shown of
young and full-grown larvae (in the small glass vessel of alcohol),
and of pupae, together with some of the soil in which they were
found (in the glass-topped box). Glossina palpalis, like other
tsetse-flies, l)ut unUke the vast majority of flies in general, does
not lay eggs ; the female produces at intervals a single larva, or
maggot, which is retained within the body of the mother until full

that spi^ead Disease.

25

grown. The maggot of G. j)al'j)ali8 is dropped by the mother in a
shady place near water, where the soil is loose or sandy, moderately
dry, and often consisting of crumbling vegetation. On being
deposited, the maggot buries itself in the loose earth; its skin
then becomes dark in colour, contracts, and hardens into a barrel-
shaped puparium or case, within which the change to the pupa or
chrysalis takes place. A female fly of this species may produce
from eight to ten larvae altogether, one at a time at intervals of
nine or ten days.

Fig. 6.— a Tsetse-Fly that speeads Sleeping Sickness,
Glossina palpalis, female, X 5.

Specimens of Glossina palpalis are shown in the attitude in
which they rest. X resting tsetse-fly can be distinguished from
any other blood-sucking fly with which it could possibly be
confused by the fact that the wings, instead of diverging at the
tips, lie closed flat over one another down the back like the blades
of a pair of scissors, while the proboscis with which the bite is
inflicted projects horizontally in front of the head.

Glossina morsilans Westw. is a widely distributed tsetse-fly
(see map), spreading nagana among domestic animals, and i
Nyasaland and Northern Rhodesia conveying to man th

26 Guide to Insects and Ticks

form of sleeping sickness caused by Trypanosoma rhodesiense
Stephens and Fantham. This species of tsetse-fly is usually
confined to definite tracts of country, known as " fly-belts," often
of very limited extent. Unlike G. palpalis, G. morsitans is not
confined to the immediate vicinity of water. The female deposits
its maggot or larva in hollows about the roots of trees, and not in
the soil under bushes, where it might be found by the scratching
of guinea-fowl and other birds in search of food. Some empty
pupa- cases are shown.

In the larger of the two glass vessels are specimens of tsetse-
flies {Glossma ixilpalis, G. morsitans ^nd G. tachinoides) before
and after a full meal, showing the extent to which the abdomen
can be distended with blood. Tsetse-flies are dependent for their
continued existence upon the blood of vertebrate animals, including
man, wild and domesticated mammals, birds and reptiles. Contrary
to what is the case in the majority of blood-sucking flies, such as
mosquitoes and horse-flies, in which the females alone suck blood,
in tsetse-flies the habit is common to both sexes. The amount of
blood imbibed at one meal is relatively considerable, the fly's
abdomen — originally empty and flat — becoming swollen out like a
bead in consequence.

The tsetse-flies on the second panel are examples of species
which have not been proved to convey sleeping sickness to man,
though many, if not all, are concerned in the dissemination of
trypanosomiasis among domestic animals. The species exhibited
are : — Glossina caliijinca Austen, G. palliccra Bigot, G. tachinoides
Westw., G. pallidipcs Austen, G. longipalpis Wied., G. austeni
Newst., G. fusca Walk., G. nigrofusca Newst., G. hrcvipalpis
Newst., G. mcdicorum Austen, and G. longipennis Corti.

TABANID FI.TES AND "CALABAR
SWELLINGS."

The disease known as " Calabar swellings," a form of filariasis
prevalent in West iVfrica, is caused by thin thread-worms of the
species Filaria (Loa) loa Stiles, the larva of which undergoes its
metamorphosis in the salivary glands of female tabanid flies of
the genus Chrysops.

that spread Disease. 27

Tabanid flies are large flies, sometimes termed horse-flies or
mangrove-flies, widely represented in tropical, subtropical and
temperate parts of the world. Only the females suck blood. The
larvae of the flies are carnivorous, and live in water, wet sand or
mud, earth or decaying vegetable matter.

In the table-case that stands at the entrance to Bay I are
shown examples of Chriisops dimidiaia v. d. Wulp and Chrijsops
silacca Austen, both of which are known to be instrumental in
the spread of the disease. Both species occur in West Africa, the
foi-mer ranging from Portuguese West Africa to Ashanti, the latter
through Southern and Northern Nigeria and the Belgian Congo.

For comparison with the two foregoing species are shown
some tabanid flies that do not, or, at all events, are not definitely
known to disseminate disease, although certain of them are
suspected of spreading forms of trypanosomiasis among domestic
animals. In many parts of tropical Africa tabanid flies are
abundant at certain seasons, when owing to the bloodthirstiness
and pertinacity of the females, the insects become an intolerable
pest, both to man and to stock. The exhibited specimens belong
mainly to the genera Chrysops, Silvius, Pangonia, Tabamts,
HiicDiatopota and Hippoccntrum, and in each case the range of
the species and any features of interest in their natural history
are mentioned.

HOUSE-FLIES AND INTESTINAL
DISEASES.

Many of the diseases broadly termed filth diseases are spread
by house-flies ; some of them are skin-diseases, others are
diseases of the alimentary canal, such as enteric or typhoid
fever, cholera, dysentery and infantile summer diarrhoea.
House-flies are something more than disagreeable com-
panions and pertinacious nuisances of the hot weather; they
are dangerous by reason of their habit of settling upon food
and contaminating it with such disease germs as they may
happen to be carrying. In America the common house-fly has
been termed the typhoid-fly, an unfortunate expression implying
that typhoid fever is the piincipal, if not the only, disease that

2 8 Guide to Insects and Ticks

is spread by the insect ; in large towns, where the arrange-
ments for the disposal of sewage are good, the greatest harm
done by the house-fly is in the dissemination of infantile summer
dian'hoea, with a large death rate. In camps and other places
away from towns, where it is difficult to secure adequate disposal
of human excreta, the danger of the spread of gastro-intestinal
diseases by flies becomes very consideralile. The organisms
causing these diseases are mostly of a bacterial nature ; enteric or
typhoid fever is due to a motile bacillus (Bacilhis typhosus Eberth-
Gaf^y), which in certain conditions exhibits from eight to twelve
delicate threads or cilia projecting from the body (fig. 7).

In a table-case that stands on the East side of the Hall,
between the statue of Sir Eichard Owen and that of Prof. Huxley,
are models of the common house-fly, Musca domcstica Linn.,
adult female (fig. 8), and a group of eggs, a larva and a pupa, all

Fig. 7. — Organisms of Typhoid Fever,
Bacillus typhosus ; X 1,500.

enlarged 28 diameters. Actual specimens are also shown of the
common house-fly and of three other species of house-fly, the
most abundant of which in houses is the lesser house-fly, Fannia
canicularis Linn.

The lesser house-fly is smaller than Musca domcstica, and is
often taken by the ignorant to be a common house-fly that has
not yet grown up. As a matter of fact, a fly that has once
emerged from its pupa-case does not increase in size. Occasionally
small specimens of Musca clomestica are met with, but these are
undersized flies whose small dimensions are due to insufficiency
or excessive dryness of food during the larval or maggot stage.
The lesser house-fly differs in its habits from the common house-
fly, and rarely associates with the latter. While the common
house-fly is found largely in tlie kitchen and dining-room, and
settles indiscriminately on the wall, the talkie, exposed food, and

that spread Disease.

29

one's hands and face, the lesser house-lly remains mostly on tlie
\ving, Hying about with a curious darting movement beneath the
gas-bracket or electrolier in the middle of the bedroom. The
lesser house-fly appears earlier in the year than the common
house-fly, and persists later, being still found in dwelling rooms
as late as November. The lesser house-fly is closely related to
the latrine-fly or privy-fly, Fannia scalaris Fabr., but the latter,
although a dangerous disseminator of intestinal disease in villages
and camps, is scarcely a house-fly ; it rarely enters houses.

Fig. 8. — Common House-Fly,

Ahisca domestica, female, x 6 ; largely responsible for the spread of typhoid fever

and summer diarrhoea.

Shown in the same case are specimens of two other house-flies,
Muscina stahulans Fin., a large fly, not frequent in its occurrence,
and Stomoxys calcitrans Linn., commonly termed the stable-fly.
This last is a biting, blood-sucking fly, common in the country and
in subui'bs, and met with sometimes in the middle of large towns.
People who do not discriminate between the different kinds of
house-fly imagine, when bitten by a Stomoxijs, that it is an ordinarj'
house-fly that has become particularly vicious. Critical examination

30 Guide lo Insects and Ticks

of the insect shows tliat it has a straight piercing prohoscis
projecting forwards from the head.

The common house-fly is incapable of biting ; its proboscis is
large and soft, and is situated on the under side of the head, and
contains numerous minute tubes through which fluid nutriment is
sucked. A fly cannot take in solid food ; if the food is dry, as for
instance a piece of sugar, the fly moistens it by ejecting salivary
fluid or by regurgitating the fluid contents of its storage-stomach
or crop. It is in this way, among others, that the fly infects food
with disease organisms, for flies are indiscriminate in their habits,
and the previous meal of the fly in question may have been made
upon the excrement of a person sufl'ering from typhoid, or of an
infant ill with summer diarrhoea. The mere walking of a fly upon
food may infect it with microbes, for the feet are hairy, and readily
carry minute droplets of substance that the fly has recently been
visiting.

At one end of the case is shown a representation of a tray of
food such as might serve for a light lunch — a plate of ham, a roll,
a few plums and a jug of milk — looking repellent by reason of the
house-flies that swarm upon it. At the other end of the case is a
representation of a heap of kitchen refuse which, by being allowed
to accumulate for some time in the dustbin, forms a suitable
breeding-ground for house-flies ; for flies, although an indoor
pest, do not breed indoors. In this exhibit are shown the
four chief phases in the life-history — eggs, larvae or maggots,
resting pupae in their brown coats, and adult flies. In the heap
of rubbish can be recognised cinders, feathers, egg-shells, fish-
bones, mouldy bread, vegetable refuse and tea leaves, the last two
being particularly harmful because, by keeping the whole mass
damp and in a state of fermentation, flies are attracted to lay their
eggs in it, their instinct prompting them to deposit the eggs where
the maggots, on hatching out, will find themselves in surroundings
most suitable for their development. Flies breed also largely in
heaps of stable manure, and any decaying and fermenting vege-
table refuse in the fields.

Just as the mosquitoes that carry malaria and yellow fever can
be kept in check liy attacking their breeding haunts, by preventing
accumulations of rain-water, by draining marshes and by spraying
with paraffin oil tracts of stagnant water, so as to prevent the
development of eggs and larvae that would grow into mosquitoes,

that spread Disease. 3 i

so in the case of house-flies, it is more practicable to attack the
next generation than the present generation, that is to say, to
prevent the development of the larvae rather than to attempt to
destroy the winged flies, and this can be done by taking measures
such that moist rubbish and stable manure are not allowed to
accumulate and serve as breeding places for the flies.

A single female of the common house-fly lays from 120 to 150
eggs at a time, and may deposit five or six batches during its life ;
and since in very hot weather the entire life-cycle may be com-
pleted in about three weeks, it is easy to account for the enormous
swarms of flies sometimes seen.

The attention of visitors is drawn to a pamphlet entitled " The
House-Fly as a Danger to Health," which can be purchased in the
Museum for a penny.

Blow-flies are not included in the series exhibited, for although
they are flies that enter houses and settle on food, particularly
cold meat and fish, they are not dangerous in the same sense as
the common house-fly. They are not attracted to dung-heaps and
other exposed faecal matter, and they breed in flesh, such as the
carcase of a recently dead animal. Blow-flies are a nuisance
principally from their habit of laying their eggs in any cold joint
of meat to which thej'' have access. The eggs soon develop into
maggots or gentles, and owing to the power which these larvae
have of liquifying the meat around them, the joint becomes putrid
much more rapidly than if it had not become " fly-blown."

SHEEP BOT-FLY.

In one of the two sloping-faced table-cases in the middle of
the floor of the Hall are shown a specimen of the bot-fly of the
sheep, Oestrus oris Linn., three larvae, and enlarged coloured
drawings ( x 6) of the larva, pupa and adult female. The larvae
or maggots of this fly live parasitically in the cavities in the front
part of the head of the sheep, and when about to become pupae,
escape from the nostrils and fall to the ground. After a time the
winged flies escape, and lay their eggs in the nostrils of sheep.

In Algeria, especially in districts in which sheep are few and
the human population fairly dense, the sheep bot-fly attacks the

32 Guide to Insects and Ticks

Kabyl shepherds, laying its eggs, while flying, in the eyes, nostrils
and lips ; the larvae, when hatched, cause intense irritation of the
conjunctiva, and of the cavities and sinuses of the nose and
throat. The disease lasts about twelve days, and is known
locally as thim'ni.

FLEAS AND PLAGUE.

Plague or l^ubonic pest is a disease of the rat, communicated
from infected to healthy rats by fleas, of which Xcnopsylla chcoins
Eothsch. is the most important in tropical and subtropical
countries. On the death of an infected rat the fleas leave the
body, and if other rats are not available, will fasten upon man,
and may communicate the disease. In man bubonic plague
proves fatal in a large percentage of cases, and a marked feature
of the disease is the enlargement of the superficial glands, such as
those of the groin and armpit, into painful swellings or buboes.

Another type of plague, known as pneumonic plague, affects
the lungs. The Manchurian epidemic of 1911 was of this type.
The infection in this case appears to have originated from plague
among the Mongolian marmots or tarbagans, Marmota hohac
Pallas, that are trapped by the Manchurian hunters for the sake
of their fur. The flea found upon the tarbagan is CaratophiiUns
silantiewi Wagn.

In one of the table-cases in the middle of the floor of the Hall
there are shown selected specimens and enlarged models of the
tropical rat-flea, Xenopsylla cheopis Eothsch. (fig. 9), which, as
stated above, is most responsible for the spread of plague in
hot countries. The tropical rat-flea is found on several other
mammals besides the rat ; the hosts are mostly rodents, but
include a few shrews. This species of flea has been spread by
rats to such an extent that it is now found all over the world ; it
does not flourish, however, in cold climates.

The model on the pedestal is that of a male, enlarged 200
diameters. The names of the parts of the insect, so far as external
features are concerned, are given in the coloured drawing below.
At the ends of the case are shown enlarged models of the head and
tlie hind end of a female tropical rat-flea ( x 250), so arranged

that spi^ead Disease.

bey

that they may be readily compared with the corresponding parts

of the male.

Models are also shown of the egg and larva of the tropical rat-
flea, enlarged 150 diameters. The eggs of fleas are eUipsoidal in
shape, similar at the two ends, and of a translucent appearance,
suggesting thin china. The eggs laid by the rat-flea fall out of the
fur of the host, and remain on the ground, usually within the

Fig. 9. — Tropical Rat-Flea,
Xenopsylla cheopls, male, X 36 ; largely responsible for the spread of plague.

nest, run or burrow of the rat, until in about a week they hatch
out into active, maggot-like larvae.

The larvae of fleas are not parasitic ; they live on the ground
either in the nest or the run of the host, and feed on all kinds of
refuse that may occur there, their mouth-parts being adapted for
chewing, and unlike those of the adult. They have no eyes, and
no legs, but move about by means of the hairs or bristles projecting
from the body, and the pair of processes or " struts " at the hind
end. After spinning cocoons and passing through a pupal or

D

34 Guide to Insects and Ticks

resting phase, they become slowly transformed into fleas, which
finally emerge from their cocoons, and invade the fur of new
hosts.

On the small glass table in the case are shown transparent
models of human red blood-corpuscles and plague bacilli, enlarged
'6,000 diameters (fig. 10). Bubonic plague, the disease that is
transmitted by the bite of various kinds of flea, of which
Xcnopsylla cheopis is the most important in tropical regions, so
that it is sometimes termed the plague-flea, is due to the presence
of minute bacterial organisms, known as Bacillus pestis Kit.,
occurring in the blood. These organisms were first discovered
during the epidemic of plague in Hong Kong in 1894. The bacilli
occur in the fluid part (plasma) of the blood, and not in the

Fig. 10. — Organisms of Plague,
Bacillus pestis, and red blood-corpuscles ; X 1,500.

corpuscles ; they may have the form of small rods with rounded
ends, and sometimes show a constriction across the middle.
Occasionally they are found in chains or series set end to end ;
each bacillus repeatedly elongates and divides across, thus
increasing the total number at a rapid rate.

On the floor of the case are shown actual specimens of the
tropical rat-flea and its larva, mounted on slips of glass. The
specimens are so small that no details can be seen ; they are
introduced into the series merely to give a correct impression of
the real size.

Under the microscope thac is set upon the table at the
entrance to Bay X on the East side of the Hall, near the statue of
Prof. Huxley, are shown specimens of the tropical rat-flea,
XcnopsyUa cheopis, in five stages of its life-history. Slide A shows

that spread Disease. 35

the eggs ; the thinness of the translucent shell is seen in the two
broken eggs. Slide B shows the larva, stained red wdth carmine
solution ; the head end is to the left. The body of the larva is seen
to be sparsely covered with stiff hairs or liristles, and there are no
eyes nor legs. Slide C shows an early pupa, shrinking in length
while still within the hairy larval skin. The first traces of the legs
can be seen. Slide D shows a later pupa, very transparent and
delicate in texture, owing to a reconstruction of all the internal
parts of the body which takes place at this period of development.
The legs are of considerable length, and the body is assuming the
size and shape of the flea. Slide E shows an adult male ; the
Ijody is now yellow, with an external hard casing of chitin,
produced into numerous hairs and spines.

Eeturning to the middle of the Hall, the visitor will see in one
of the two sloping-faced table-cases an enlarged, coloured drawing
( X 40) of a female specimen of the human flea, Ptdex irritans
Linn. The flea of man is larger and darker in colour than the
tropical rat-flea {Xenopsi/Ua cheopis), and has larger stigmata or
breathing pores, larger claws on the feet, and much larger eyes ;
the piercing mouth-parts, also, are stronger and broader. The
long bristle which in the rat-flea passes backwards across or near
the eye is much lower down in the flea of man ; and in the latter
there is no internal bar extending from the mid-coxa into the
thorax — this last feature can only be seen in specimens that have
been made transparent so as to render the internal structures
visible. Other differences between the species occur in the sexual
organs.

Under the microscope placed on the West side of the Hall
near the entrance to Bay I. are shown twelve slides, of which nine
a)'e preparations of adult fleas of general interest.

A is a male tropical rat-flea, Xenopsylla cheopis Eothsch.
(fig. 9). As already explained, this flea is common on rats (and
other rodents) in warm countries, having become almost cosmo-
politan in distribution. It is known to transmit the bacillus of
bubonic plague from infected rats to man, and is frequently terpied
the plague-flea.

B is a male flea of the species Ctcnophthalvms agyrtes Heller.
This species of flea is common on rats, and also on field-mice,
stoats and weasels, in Europe. It is not known to transmit any
disease. It is distinguished from "A" by having no eyes, and by

D 2

o

6 Guide to Insects and Ticks

having three spines on the lower edge (gena) of the head. There
is also a comb of spines projecting back from the pronotum or first
division of the thorax.

C is a male Lcptopsijlla iiinsculi Duges, the common flea of the
mouse, but also found on the rat. Though primarily European,
it is now almost cosmopolitan. It has a comb of spines on the
pronotum, but no eyes, and is distinguishable from "B"' In" having
four genal spines instead of three.

D is a male Ceratophi/Uus fasciatus Bosc, a common rat-flea,
almost cosmopolitan in distribution. It has eyes, and a comb of
spines on the pronotum, but no genal spines.

E is a male Geratophyllus silantieici Wagn., the flea found on
the Mongolian marmot, Marmota bohac Pallas, and responsible for
the spread of pneumonic plague. It is with difhculty distinguish-
able from the common rat-flea (D).

F is a female cat-flea, Ctcnoccphalus felis Bouche, found not
only on cats, but also on wild species of felidae, and on dogs. It
is widely distributed, and is distinguished by having eyes, a comb
of spines on the pronotum, and a row of eight spines (genal spines)
at the lower edge of the head.

G is a female dog-flea, Ctcnoceplialus canis Curtis, found on
cats as well as dogs. The flea resembles Ctcnoccphalus fells, but
has the head more rounded.

H is a male human flea, Pitlex irritcuis Linn. This flea is
short and thick-set, with eyes, but no comb of spines on the
pronotum. It is almost cosmopolitan in distribution.

J is a young female jigger flea, Dcrmatopliilus pcnctratis Linn.
The female jigger flea burrows into the human skin, and its
abdomen becomes so enormously distended with eggs as to attain
the size of a small pea. The part of the skin affected may become
ulcerated and infected with various pathogenic bacteria, and so
lead to serious consequences. Although a native of Mexico, Brazil
and Argentina, the jigger flea is now spread also over most parts
of tropical Africa, and has even reached India. It attacks other
mammals besides man.

The slides K, L and M are preparations of a louse and two
bugs, and will be referred to under their respective headings.

tJiat spread Disease.

37

BED-BUGS AND DISEASE.

In one of tlie two sloping-faced table-cases in the middle of
the floor of the Hall is a specimen and an enlarged, coloured
drawing (x 20) of a female bed-bug, Cimcx or Clinocoris Icctu-
larius Linn. ; and under the microscope at the entrance to Bay I
are shown specimens (slides L and M) of this species and the
bed-bug of tropical Africa and the Oriental Eegion, Clinocoris
rotundatus Sign.

Clinocoris lectularius (fig. 11), although commonly termed the
European bed-bug, is a parasite which h\ the facilities for travel

r

"■^1

^ '-^'

't"

_ijj#'

Fig. 11. — Common Bed-Bug,
Clinocoris lectularius, male, X 10.

now possible has been spread all over the temperate and tropical
parts of the world. It differs from C. rotundatus by its relatively
broader abdomen ; the prothorax also is broader, and the lateral
lobes project more forward, and almost reach the eyes. The form of
the mouth-parts of a bed-bug are seen in slide L. The labium
has the form of a segmented proboscis ; the four bristles seen
projecting from the front of the head are the two maxillae and
two mandibles, which in the living insect lie within a groove in
the labium.

The common bed-bug has been suspected of can-jing the virus
of various diseases, such as leprosy, typhus and relapsing fever,

^8 Guide to Insects and Ticks

o

from infected to healthy persons, and Clinocoris rohmdahis is
known to be the carrier of a piroplasma parasite, Lcishmania
doiiovani Laveran and Mesnil, the cause of the tropical disease
kala-azar, common in India.

LICE AND DISEASE.

Apart from tlie irritation which they cause, in some cases so
great as to lead to loss of sleep and nervous prostration, lice are
noxious insects because of their capacity for spreading typhus fever
and some forms of relapsing fever (those of Europe and North
x\frica) ; lice have also been suspected as the infective agent in
certain cases of leprosy, tuberculosis and plague. The organism
of typhus fever has so far not been identified. That the causal
organism undergoes some part of its development in the louse is
evident from the fact that lice are especially infective from the
fifth to the seventh day after feeding upon a person suffering from
typhus fever. The organisms of the relapsing fevers are spiro-
chaetes, blood parasites of spirally twisted, thread-like form.

Lice feed entirely upon blood, which they suck through
punctures made in the skin ; they soon die when removed from
the body, and differ in this respect from fleas and bugs. Three
species of louse occur on man — the clothes-louse or body-louse,
Pccliculus JiUHuoiusLiinu. (fig. 12), the head-louse, Pt;(//c»/?/s capitis
de Geer, and the crab-louse, Phihirus pubis Linn. These are
also found occasionally upon cats, dogs and monkeys living in
association with man. Various kinds of mammals, from elephants
to shrew-mice, have their own particular species of lice.

In one of the two sloping-faced cases in the middle of the Hall
are shown some specimens and enlarged coloured drawings ( x 50)
of the clothes-louse and head-louse. In the same case a series of
five lenses is arranged over mounted specimens of a head-louse,
some pieces of human hair with nits or eggs of the louse, a
clothes-louse, a crab-louse, and a louse (Pediculus schaffi Fahr.)
from a chimpanzee. Under the microscope near the bust of
Sir William Flower, on the West side of the Hall, is shown a
mounted specimen (slide K) of the clothes-louse.

that spi^ead Disease.

39

The clothes-louse is larger than the head-louse, and the sides
of the abdomen are less deeply cleft between the segments. The
antennae are slightly thinner in the clothes-louse than in the
head-louse, and the front border of the thorax is less rounded.
Other differences occur in the female sexual organs. In the crab-
louse the body is shorter than in the two former species, and the
thorax is broader than the abdomen ; along each side of the
abdomen are projections which at their tips carry pencils of

Fig. 12. — Clothes-Louse or Body-Louse,
Pediculus humanus, female, X IS ; largely responsible f(ir the spread of typhus fever.

hairs. In the louse of the chimpanzee the lateral margins of
the abdomen are straight in front, but behind they present the
appearance of a saw.

A female louse lays four or five eggs a day for about a month,
and then dies. There is no caterpillar or maggot stage ; the
young, on hatching out, differ from the adults only in their smaller
size and in certain trifling differencesi of structure. As they grow
they moult the skin three times before arriving at the adult

40 Giiidc to Insects and Ticks

condition, \Yhich is reached in about twelve days from the time of
the hatching of the egg.

Lice are commonest in the poorer districts of a town, and
spread rapidly among the children in a school. In times of war
lice are apt to become particularly troublesome owing to their
rapid increase in numbers, and the ease with which they can
spread in the crow^ded hfe of a camp ; the men have usually but
few opportunities for effecting a complete change of garments and
otherwise cleansing themselves, and so the conditions are favour-
able for a continuance of the infestation.

The attention of visitors is directed to a pamphlet entitled
" The Louse and its Eelation to Disease," which can l^e purchased
in the Museum for a pe-nny.

TICKS AND DISEASE.

The transmission of several diseases caused by blood-parasites,
known as spirochaetes, may be traced to the Ijite of ticks, c.<j.,
human tick-fever or relapsing fever of tropical Africa, due to
S2nrochaeta diittoni Novy and Knapp (fig. 13), conveyed from one
person to another by the tick OrnitliocJoros mouhata Murraj-
(fig. 14) ; and spirochaetosis in fowls and cattle, the fowl-tick
being Argas imrsicus Oken. A typhus-like disease in man, known
as Eocky Mountain spotted fever, is spread by the tick Dermacentor
venustus Banks, and a recently observed obscure affection known
as tick-paralysis in man, sheep and dogs, has also been shown to
be due to the effects of tick-bites. Concerning the blood-parasite
of heartwater of sheep, etc., conveyed by the bont tick, Amhhiomma
hebraeum Koch, in South and Central Africa, but little is known.
A somewhat similar disease, the East Coast fever of cattle, is due
to Thcilcria, a blood-parasite which occurs within the red blood-
corpuscles of the host, like the forms of PiropJasma {Babesia and
Nattallia), which cause redwater or Texas fever of cattle in many
of the warmer parts of the world, malignant jaundice of dogs in
India and South Africa, biliary fever of horses in Africa and India,
and carceag of sheep in Southern Europe, all transmitted by ticks
of the genera Rhipiccphalns, Margaropus, and their allies.

In one of the two sloping-faced cases in the middle of the Hall,

that spread Disease.

41

between the main staircase and the statue of Sir Eichard Owen,
there is shown, on the North side, a series of ticks arranged in
three groups. The first group consists of ticks that convey disease
to human beings, and inckides Ornitlwdoros mouhata Murray,
Ornitlwdoros savigniji Aud. and Derinaccnior vcimstus Banks.

Ornitlwdoros mouhata (fig. 14) is- very widely distributed in
Africa, and the regions wliere it is Iviiown to occur are marked in
red in the map that is placed by the side of the specimens. This
tick, which sometimes attacks domestic animals as well as human
beings, transmits the blood-parasite Spirochacta duttoni Novy and
Knapp, the cause of the human relapsing fever of tropical Africa.

Fig. 13. — Organisms of African Relapsing Fever,

Sinrochaeta duttoni, and red blood-corpuscles ; X 1,500.

The larval stage of the tick is not well developed in this species,
and is inert, the tick emerging from the eggshell as a nymph.
After freeing itself from the larval skin, the nymph is ready to
feed. It casts its skin several times before becoming adult, a
moult taking place after each meal of blood. The female tick does
not lay eggs until it has fed on blood. The spirochaetes are taken
up by the tick whilst sucking blood from an infected person. They
make their way into the ovaries of the tick, x^enetrating into the
undeveloped eggs and multiplying within them. The first nymphal
stage that develops from these eggs is capable of conveying the
disease. The spirochaetes can be transmitted to the third genera-
tion of ticks, even if the second generation was fed on blood free
from spirochaetes.

42

Guide to Insects and Ticks

Ornitliodoros savignyi is very widely distributed in Africa, from
Egypt to Cape Colony, and is also recorded from Southern India.
It occurs on both man and domestic animals, and experiments
have shown that the species is capable of transmitting the human
relapsing fever of tropical Africa.

Dcrmaccntor venusius is a North American form, ranging from
British Columbia southwards to Northern New Mexico, and from
the foothills of the Eocky Mountains in Colorado to the base of the
Cascade Eange, in Oregon and California (see map). Almost all
the small mammals found in the localities in which this tick occurs
serve as hosts for the larvae and nymphs. The adult tick is

f\ if'*

Fig. 14. — Ax Afeicas Tick,

Omithodofos moubata, female, under surface, X 4 : larjrely lespousilile for the spread of

the relapsing fever of Africa.

nearly always met with on the larger domestic animals, especially
on horses and oxen. The species also attacks man, and transmits
the spotted fever of the Eocky Mountains, a disease with a high
rate of mortality. According to some authorities, more than
one species has been included under the name D. venustiis, and
the species conveying Eocky Mountain fever should be called
D. andcrsoni Stiles.

The second group exhibited comprises examples of ticks that
convey disease to domestic animals, but not to human beings ; it
includes the following species : —

lihipicephalus cvcrtsi Nn. is a tick found in most parts of
Africa (see map), and transmits East Coast fever of cattle and the

that spread Disease. 43

South African biliary fever of horses. It is known to attack oxen,
sheep, horses and dogs, and has also been met with upon antelopes,
giraffes and elephants.

Ixodes ricinus Linn, is apparently the chief carrier of redwater
fever, a form of piroplasmosis, in cattle in Northern Europe. It
ranges through Europe, North Africa, Transcaucasia, Arabia,
China, Japan and North America. It is met with upon sheep,
cattle, goats, horses, dogs, deer, hedgehogs, and many other
mammals, also lizards, and occasionally on man.

Amblyomma hebraeum Koch is known as the bont tick ; it is a
common species in South Africa, and is distributed as far as
Central Africa. Owing to the fact that it transmits heartwater in
sheep, goats, and sometimes in cattle, this tick is of considerable
importance to agriculturists. Further remarks upon the bont tick
are given below.

The third group includes examples of ticks that are not known
to convey disease to man or other vertebrates ; three species are
shown, as follows : —

Amhh/omma cohacrens Donitz is found in Uganda upon
buffaloes.

Dermacentor rhinocerotis de Geer ranges from South Africa to
Uganda and British East Africa, and is found usually upon the
rhinoceros, but sometimes on antelopes.

Derinacentor circumguttatits Nn. is met with upon elephants in
Uganda and West Africa.

In one of the table-cases in the middle of the Hoor of the Hall
is a series of specimens and enlarged models of the bont tick,
Amhhjomma hebraeum Koch, an African tick parasitic upon sheep,
goats and oxen. The exhibited series includes a drawing of a
small group of eggs, a model of a larva enlarged to the same size
as the models of the adult, namely 20 diameters, and another
model of the same larva still further enlarged ( x 120) to show the
details of structure. Models are shown of an adult male and
female ( x 20), and actual specimens are mounted on the tablet
between them. The great model in the middle of the case repre-
sents the female when fully gorged and distended with blood and
eggs, magnified to the same extent ( x 20). Two actual specimens
of gorged females, of the size of cherries, are shown in the small
glass vessel of alcohol.

The bont tick is capable of transmitting to sheep, goats and

44 Guide to Insects and Ticks.

oxen the deadly disease known as heartwater, when it bites a
healthy animal after having fed upon one that is suii'ering from the
disease. The organism that causes the disease has not been seen
in the l^lood of the vertebrate host, but experimental investigation
shows that it is not transmitted through the egg of the tick as are
some other tick-borne blood-parasites of the genera Piroplasma
and Spirochaeta.

The larva, nymph and adult of the bont tick feed on three
different individual hosts, dropping to the ground after each meal ;
the organisms imbibed with the blood of an infected host by the
larva are transmitted to the second host by the nymph ; and
similarly, if a nymph feeds on an infected host it may, wdien adult,
transmit the organisms to the third host. Mating of the ticks
occurs on the skin of the third host, and the female then feeds
until fully gorged; afterwards it drops to the ground, and in
course of time produces a vast numl)er of eggs.

INDEX.

Amblyomma, 40, 43-44
Anopheles, 8-18, 20

•Babesia, 40
Bacilhis pestis, 34
Bacillus typhosus, 28
Bed-bugs, 37
Blood-worm, 17
Blow-flies, 31
Bont tick, 40, 48-44
Bot-fly, 31

Calabar swellings, 26
Ceratophyllus, 32, 36
Chironomus, 16-17
Chrysops, 26-27
Ciniex, 37
Clinocoris, 37-38
Crab-louse, 38-39
Ctenocephalus, 36
Ctenophthahnus, 35
Culex, 13-16, 18, 20-21

Dermacentor, 40-43
Dermatophilus, 36
Diarrhoea, 27-30
Dourine, 24

Elephantiasis, 20
Enteric fever, 27-30

Fannia, 28-29
Filaria, 20, 26
Fishes that devour ihe

larvae of mosquitoes,

21

Fleas, 32-36
Forest-fly, 24

Gall-sickness, 24
Gambusia, 21
Glossina, 22-26
Gnats, 8-20

Haplochilus, 21
Head-louse, 38
Heart-water, 40, 43-44
Hippobosca, 24
Horse-fly, 27
House-flies, 27-31

Ixodes, 43

Jigger flea, 36

Kala-azar, 38

Laverania, 8
Lebistes, 21
Leishmania, 38
Leptopsylla, 36
Lice, 38-40

Malaria, 8-12
]\Iangrove-fly, 27
]\Iargaropus, 40
Microscopes, 7, 34-38
ilidge, 16-17
Millions, 21
Mosquitoes, 8-20
Musca, 28-31
Muscina, 29

Nagana, 22-23, 25
Nuttallia, 40

Oestrus, 31
Ornithodoros, 40-42

Pediculus, 38-40
Phthirus, 38-39
Piroplasma, 40
Plague, 32, 34, 41
Plasmodium, 8-12
Pulex, 35-36

Rat-flea, 32-36
Eedwater, 43
Relapsing fever, 38,40-42
Rhipicephalus, 40, 42

Sheep bot-fly, 31
Sleeping sickness, 22-26
Spirochaeta, 40-41
Stable-fly, 29
Stegomyia, 18-20
Stomoxys, 29
Summer diarrhoea, 27-

30
Surra, 24

3:abanid flies, 26-27
Theileria, 40
Ticks, 40-44
Tiger-mosquito, 18
Top-minnows, 21
Trypanosoma, 22-24
Tsetse-flies, 22-26
Typhoid fever, 27-30
Typhus fever, 37-39

Xenopsylla, 82-35

Yellow fever, 18-20

GUIDE-BOOKS.

{The Guide-books can be obtained at the Museum. Postage extra.)

General Guide to the Museum, 8vo. 3f7.

Guide to the Baces of Mankind (Anthropology), 8vo. Ad.

Galleries of Mammals, 8vo. 9d.

Great Game Animals, 8vo. Is.

Elephants (Recent and Fossil), 8vo. Gd.

Horse Family, 8vo. Is.

Domesticated Animals (other than Horse^;), Bvo. 6(7.

Whales, Porpoises, and Dolphins (order Cetacea), 8vo. id.

Gallery of Birds, 4to. 2s 6^7.

General Series of Birds, 4to. 6d.

Nesting Series of Britisli Birds, 4to. id.

Gallery of Rex^tilia and Amphibia, 8vo. 6d.

Gallery of Fishes, 8vo. Is.

British Vertebrates, 8vo. Is.

Insect Gallery, 8vo. Is.

Crustacea, Arachnida, Onychophora and Myriopoda, 8vo. Is.

Shell and Starfish Galleries, 8vo. 6d.

Coral Gallery, 8vo. Is.

Fossil Remains of ^lan, Svo. 4f7,

Fossil Mammals and Birds, 8vo. Gd.

Fossil Reptiles and Fishes, Svo. 9d.

Fossil Invertebrate Animals, 8vo. Is.

Mineral Gallery, 8vo. Id.

The Student's Index to the Collection of Minerals, Svo. 2d.
An Introduction to the Study of Minerals, with a Guide to the Mineral
Gallery, 8vo. 6(7.

to the Study of Rocks, Svo. Gd.

• ■ to the Study of Meteorites, Svo. Is.

Guide to Sowerby's Models of British Fungi, Svo. 4f7.

Drawings of Field and Cultivated IMushrooms, and Poisonous or

Worthless Fungi, Svo. Is.

the British ilycetozoa, Svo. Sd.

List of British Seed-plants and Ferns, Bvo. id.

Special Guides : No. 2. History of Plant Classification, Svo. id.

No. 5. Exhibition of Bible Animals, Plants, and IMinerals,

Svo. 6d.

No. 6. Flight Exhibition, Svo. 6f7.

Handbook of Instructions for Collectors, Svo. Is. 6(7. ; or in eleven separate

sections, at 3(7. or 4(7. each.
The House-Fly as a Danger to Health, Svo. 1(7.
The Louse and its Relation to Disease, Svo. 1(7.

CATALOGUES (Selection).

History of the Collections : —

Vol. I. Libraries ; Botany ; Geologv ; Minerals. 1904, Svo. 15s.
Vol. II. Zoologv. 1906, Svo. £l lOs.

Vol. II. Appendix. By Dr. A. Giinther, F.R.S. 1912, Svo. 5s.
Catalogue of the Librarv of the British Museum (Natural History).

Vols. I.-V. 1903-15, 4to. £1 each.
Report on the Zoological Collections made .... during the Voyage of

H.M.S. ' Alert,' 1881-82. 54 Plates. 1SS4, Svo. £1 10s.
Report on the Collections of Natural History made in the Antarctic Regions
during the Voyage of the ' Southern Cross.' 53 Plates. 1902, roy. Svo. £2.
Reports on the Natural History of the 'Discovery' National Antarctic
Expedition, 1901-4 :—

Vol. I. Geology. 10 Plates, 72 Text-figures, 2 Maps. 1907, 4to. £1 10s.
Vol. II. Zoology (Vertebrata : Mollusca : Crustacea). 33 Plates, 146

Text-figures, 1 Map. 1907, 4to. £3.
Vol. III. Zoologv (Invertebrata) and Botany (Marine Algse : Musci).

51 Plates, 8 Text-figures, 1 Chare. 1907, 4to. £2 10s.
Vol. IV. Zoology (various Invertebrata). 65 Plates, 1 Text-figure. 1908,

4to. £1 15s.
Vol. V. Zoology (Vertebrata and Invertebrata) and Botany. 28 Plates,

19 Text-figures. 1910, 4to. £1 10s. ,
Vol. VI. Zoology (Invertebrata) and Botany. 8 Plates, 1 Key-plate,
1 Text-figure. 1912, 4to. 16s.
First and Second Reports on Economic Zoology. Text illust. 1903-4, roy.
Svo. Os. each.

CATALOGUES (Selection) —continued.

Catalogue of Monkeys, Lemurs, and Fruit-eating Bats. 21 Woodcuts. 1870,

8vo. 4s.
Chiroptera (Bats). Vol. I. Megachiroptera. 85 Text-figures.

1912, Svo. £2 10s.

• Carnivorous Mammalia. 47 Woodcuts. 1869, 8vo. 6s. Qd.

Seals and Whales. 2nd Edition. 101 Woodcuts. 1866, Svo. 8s.

Supplement. 11 Woodcuts. 1871, 8vo.. 2s. 6fZ.

Ruminant Mammalia (Pecora). 4 Plates. 1872, -8vo. 3s. 6fZ.

Ungulate Mammals. Vols. I.-IV. Text illust. 1913-15, 8vo.

7s. 0(Z. to 10s. 6(Z. a volume.
Monograph of the Okapi. Atlas of 48 Plutes, with Explanations, &c. 1910,

4to. £1 5s.
Catalogue of IMarsupialia and Monotremata. 28 Plates. 1888, Svo. £1 8s.
the Mammals of Western Europe. 213 Text-figures. 1912,

Svo. £1 6s.
the Heads and Horns of Indian Big Game hequeatlied by

A. 0. Hume, C.B., to the British Museum (Natural History).

16 Text-figures and a portrait. 1913, Svo. 2s.
. Birds. Vols. X.-XXVII. Woodcuts and Coloured Plates.

1885-98, Svo. 14s. to 36s. a volume. {Vols. I.-IX. out of print.)
General Index to a Hand-list of the Genera and Species of Birds. 1912, Svo. 10s,
Catalogue of Birds' Eggs. Vols. I.-IV. Coloured Plates. 1901-12, Svo.

£1 5s. to £2 7s. 6cZ. a volume.
Lizards. 2nd Edition. Vols. II., III. Plates. 1885-87, Svo.

20s. and 20s. {Vol. I. out of print.)
Snakes. Vols. I.-III. Woodcuts and Plates. 1893-96, Svo.

17s. 6fZ. to £1 Os. each.
Fishes. 2nd Edition. Vol. I. Woodcuts and 15 Plates.

1895, Svo. 15s.
the Freshwater Fishes of Africa. Vol. I. 270 Text-figures.

1909, imp. Svo. £i 12s. 6fZ.— Vol. II. 382 Text-figures.

1911, imp. Svo. £2 5s.— Vol. III. 351 Text-figures. 1915,

imp. Svo. £2 5s.
• The British Species of Pisidium (Recent and Fossil). 30 Plates.

1913, Svo. 10s. 6fZ.
Spiders of Burma. 1895, Svo. 10s. &d.

A Revision of the Ichneumonidse. Parts I-IV. 1912-15, Svo. 4s. to 6s. apart.

IMonograph of Culicidse, or Mosquitoes. Vols. IV., V. Woodcuts and Plates.

1907-10, Svo. £1 12s. OcZ. and £1 5s. a volume. {Vols. I.-III. out of print.)

Handbook of Tsetse-Flies. 10 Coloured Plates, 24 Text-figures, and a Map.

1911, roy. Svo. 5s. 6fZ.
Illustrations of British Blood-sucking Flies. 34 Coloured Plates. 1906, roy.

Svo. £1 5s.
Catalogue of Lepidoptera Phalsaense (Moths). Vols. I. -XIII. Woodcuts and
Atlases of Coloured Plates. 1898-1913, Svo. £1 5s. to
£2 2s. GfZ. a volume (including the Plates).

Orthoptera. Vols. I.-III. 1904-10, Svo. 10s. to £1 a volume.

Homoptera. Part I. Cicadidse. 1906, Svo. 5s.

British Hymenoptera. 2nd Edition. Part I. New Issue.

11 Plates. 1891, Svo. 6s.

— Chsetopoda. A Polychfeta : Part I. — Arenicolidfe. 15 Plates.

68 Text-figures. 1912, roy. Svo. £1 7s. Q>d.

British Echinoderms. Woodcuts and 16 Plates. 1892, Svo.

12s. 6d.

Madreporarian Corals. Vols. I.-VI. Plates. 1893-1906, 4to,

18s. to 35s. a volume.

Illustrations of Australian Plants collected in 1770 during Captain Cook's

Voyage round the World in H.M.S. 'Endeavour.' Part I. 101 Plates.

1900, fol. £1 5s.— Part II. 142 Plates. 1901, fol. £1 15s.— Part III.

77 Plates and 3 Maps. 1905, fol. £1 5s.

Synopsis of British Basidiomycetes. 5 Plates and 145 Text-figures. 1908,

Svo. 10s.
Monograph of British Lichens. Part II. 59 Plates. 1911, Svo. £1.

the Mycetozoa. 2nd Edition. 201 Plates and 56 Woodcuts. 1911,

Svo. £1 10s.

The above-mentioned Catalogues may be purchased of Messrs Longmans,
Green & Co., 39, Paternoster lioiv ; Mr. B. Quaritch, 11, Grafton Street,
New Bond Street; and Messrs. Dulau & Co., Ltd., 37, Soho Square; or
at the Natural History Museum, Cromwell Road, London, S.W. A more
detailed list may be obtained on application to the Director of the Museum.

BRITISH MUSEUM

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DAYS AND HOURS OF ADMISSION.

The Exhibition Galleries are open to the Public, free dailj' — •

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By Order of the Trustees,

L. FLETCHER,

Director.

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