The Flea

visory Committee, under whose direction the investigation was carried out, consider that: firstly, in nature, plague is spread among rats by the agency of rat-fleas; secondly, bubonic plague is not di

emics they occur during some part of that se

wledge of rat-fleas, their forms, their habits, an

old black rat (M. rattus) chiefly infests ships and seaports. The brown rat (M. norwegicus) is the most aggressive and distinctive. But all three, by accidental transference from port to port in ocean-going vessels, have become distributed

ant part in plague infection; and a full account of its fleas, and of experiments in transferri

ats to squirrels. In harvest time rats migrate to the fields and use the same runs and holes as the squirrels. Under these conditions a transfer of fleas from rats to ground-squirrels is almost certain to ensue. Two species of flea have been recorded from the Californian ground-squirrel, and both are parasites of rats. The chain of evidence is

ost likely be infected. It is obvious that a plague-sick rat may travel about leaving as it wanders a trail of infected fleas behind it. Rats, too, are frequently transported with certain kinds of merchandise and carry their fleas to the most distant parts of the globe, travelling with all the speed and luxury which modern steamships afford. Rats will dive into sacks of grain or bran and hide, so that the bag can be loaded as cargo without anyone suspecting the presence of a rat inside. M. rattus and its fleas, from the habits of the host, are especially likely to be transpor

arpets, chopped straw, old sacking, paper shavi

arv? of fleas are often found. Where trade is carried on in sacks and gun

ough the fleas jump on to a man's hand they take some time to begin to feed. They crawl about and seem to have some doubt where best to begin their sucking operations. Also it has been observed that the fleas much more readily fall off a man's arm

s corresponds in a general way with the plague mortality. During the season when plague is bad the average number of fleas per rat is above the mean.

reat majority of these may be called casual visitors. Six species of Sarcopsyllid? are also occasionally fo

five in number, and the readiness with which th

he world by rats, it now occurs, occasionally, in all warm climates. It is the common rat-flea of the tropical and sub-tropical world. In India it often happens that the whole of the fleas collected from rats prove to be of this species. But it cannot, apparently, flourish in cold countries. In the warmer temperate zones, such as the Mediterranean

monly found on black and brown rats in the British Islands and the other countries of Northern and Central Europe. It readily bites man, and there is no reas

osely allied species of rat-flea whic

host. From mice it frequently moves to rats, and it has been found on them in various parts of Euro

tfordshire, Hampshire and Suffolk one half the fleas from rats, collected in farmyards and hedgerows, were found to belong to this species; but whether it is as common on rats all over England is unkno

leas are found vary greatly in different parts of the world. For instance, in San Francisco nine per cent. of the fleas collected from ra

ich follow in his rear, exterminate numbers of the weakly native small mammals and

eference for certain individuals. When the flea has refused to bite the human arm, it becomes necessary to check the experiment by trying whether the refusal is merely due to want of hunger. For this purpose a rat must be at hand. It can be secured on a board by two bandages fixed at each end by drawing pins. The rat l

t the true rat-fleas are usually on the hind-quarters of the hos

rat-fleas in the matter of food a long series

adily attack all animals, not being particular in the choice of a host. (4) Rat-fleas deprived of their food for from 72 to 96 hours attack and feed on man more readily than at other times. (5) Rat-fleas, even when starved, prefer their true host to man. (6)

unknown. Bat-fleas also, as a rule, have maxill? shaped like dumb-bells; but in one genus (Thaumopsylla), found on fruit-bats, they are triangular as in other fleas. The maxill? as the reader may remember, are parts of the insect's mouth, and, though placed like jaws on each side of the aperture, they are n

er fleas. They breed in hollow trees, caves, ruins, church-towers and lofts where bats hibernate or spend the hours of daylight. The larv? feed on the droppings of the bats, and the mature insect, after emerging from the pupa case, tak

rk hard for a precarious diet of gnats round a Siberian village. Two sharply divided groups of bats exist: (1) The fruit-bats (Macrochiroptera) with flat molar teeth adapted for a vegetable diet. These are found in the warmer parts of the Old World but not in America. (2) The insectivorous bats (Microchiroptera) whose molar teeth are equipped with sharp cusps for biting

nocturnal animals, lends colour to the suggestion that fleas which are blind have lost t

END

C VIEW OF

ONAP

aptera. Latr

of three main segments which lie when at rest in a groove. Three thoracic segments, always free, each consisting of a notum and a sternum. The sterna of the second and third segments are further divided into a sternum, an episternum and an epimeron, the two latter constituting the pleura. Wings and rudiments of wings entirely absent. Abdomen of ten segments of which the sternite of the first segment is s

opsyllid?. Tas

the unpaired basal segment. Genal edge of head always produced downwards into a triangular process situated behind th

itic fleas. About fourteen species have been described, which can be gr

licid?. Tasch

g, except in a few cases, of five, or more, segments inclusive of the unpaire

he majority o

eratopsyllid?

e are several genera, and about twenty-five species have been described. In most of the bat-fleas the ma

fication of the order Siphonaptera based on the morph

END

TISH FLEAS AN

Fleas (Siphonaptera)

Usua

ex,

tans Ma

ylla,

is, Roth

psylla

ei, Bouch

ephalu

is, Cu

is, Bo

syllus

uli, Dal

psylla,

Puffin and Manx shear

phyllu

iatus,

s, Rothsch. Ho

Schrk. Squir

s, Wlk.

gner Bank-vole

, Grube Bank-vo

sch. Stoats, Vol

hrk. Chickens

ill?, Wl

Rothsch.

s, Wagner

Rothsch. H

is, Curt. H

b?, Gerv

Rothsch.

any birds: especiall

, Bokeman Nes

othsch. Gannet

di, Waterst.

thalmus

eller Field-m

obilis, Roth

dentatus,

la, Jord.

emus, Rot

la, Jord. a

nthus, Rot

us, Rothsch

sylla,

cis, Da

or, Da

uti, Da

ylla, R

uli, Du

lis, Rothsc

ceras,

gner Long-tai

opsylla,

p?, Cu

psylla

us, Curt.

us, Rothsch.

Rothsch. N

s, Kolen Pip

us, Kolen L

opsylla,

, Rothsch. P

ajor, Rothsc

END

NG AND PRES

nd is by mounting each in Canada balsam on a slide for the microscope. The advantage of the former method is that the material can be used for dissection. The student c

ake the tubes like a test-tube holder. Fleas dried and preserved loose in a box, or g

found in the hair and under the feathers, and also in the places where the animals habitually sleep. The best plac

at all the fleas leave as soon as the body of the host gets col

of chloroform or benzine can be poured on it. In a short time the fleas will be found dead in the bag

ul. If a flea is touched with a brush of this kind which has been dipped in chloroform, benzine, or alcohol, the insect sticks to the brush, but can be easily floated off into the tube of preservativ

ost, but as many specimens as possible should be secured, be

ntries it may not be always easy to do this. In such cases the skin of the host must be preserved with the tube for

were obtained are of little or no scientific value. For this

s to write in pencil on a small piece of paper which

live, or the fleas will have left their hosts before they can be secured and examined. Field-mice caught in the ordinary small penny mouse-trap are often found dead in the morning. The best traps are made on the prin

into a small white linen or holland bag. The animal can then be killed by tapping its head or breaking its neck

he flea-collector. I have heard of a collector of small mammals who travelled through remote parts of Spain and never lost an occasion for putting down his traps when he had to change trains at a

o time the nest should be slightly damped with water. In every case a label should be put into the receptacle to preserve the name of the bird which built the nest. The bottom of the nest may sometimes be seen to be full of the larval fleas; but in any case fleas will probably emerge from pup?. The fleas will continue appearing for as much as six weeks or eight weeks after the young birds have left the nest. They m

tropical and semi-tropical countries. The males are very difficult to find, but the females are large and very parasitic. They have the appearance of a small wart firmly fixed to the skin

END

IOGR

ef and most recent works. Many hav

g (1880), Die

of all subsequent scientific work. He divides fleas into (a) chigoes,

iss des Rhyncoprion penetrans. Bull.

bits of the chigoe. Many referenc

s. Vol. XXIII., p. 199; (1893) Vol. XXVII., p. 347; (1898) Vol. X

essor at the Russian University of K

hfauna. Schriften der Physik.-?konom. Gesellscha

account of our present knowled

Floh aus dem baltischen Bernstein. Schriften der Physik.-?k

f the fossil

es Flohkopfes sowie über die Ontogenie, Phylogenie und Sy

iz. (1) Integricipita; (2) Fracticipita. By the chief authority on f

f the non-combed eyed Siphonaptera. Parasit

rk, which includes an ac

Sarcopsyllid?. Thompson Yates and Johnston Laborato

rn account of

ith a complete list and bibliography of the group. Proc. U.S. National M

s, beginning 1699, mo

f the American Siphonaptera. Proc. U.S

ts and their fleas. A

Further Contributions, etc., Vol. 7, p. 539; (1903) Vol. 10, p. 317; (1904) Vol. 11, p. 602; (1905) Vol. 12, pp. 153

w species in the writer's collection. Many fine plates illu

n the systematic position of the Siphonapte

die systematische Stellung

tion of the Siphonaptera. Proc. Boston

eue floh?nliche Fliegengattung. Zoo

enese der Aphaniptera entdeckt? Zool

us reply

iciden im System. Archiv für Naturge

ung der Puliciden. Zoologischer Anzeiger,

icism of the views

ischen Stellung der Fl?he. Revue Russe d'

nces are chiefly to wor

on Plague Investigations in India. Journal

ague Numbers." Many references to observ

Epidemiology. Journal o

pidemie in Formosa. Centralbl. f

n de la Peste. Annales de l'Ins

n de la Peste. Annales de l'Ins

insects in the epidemiology of the plague

rg with fleas. This important research was written i

nsects and Disease

ontains a chapter on fleas and plague. Some g

N

ome

rs of f

n?, 2

nipt

era

hnid

omys

illoe

opods

us pes

er,

Mr Ca

eas, 2

, head-fl

, 12

ongi

ograp

deat

-syst

Doct

n, M

Plague

in,

leas, lis

leas, num

snak

ia, plag

vora,

s, attacked

esb

og-flea distin

and Pro

style

llid?, 17

yllus an

arre

atus, 89

alli

llinu

hschil

gabun

goe

n ba

owing h

ributio

parr

ant fema

ral proce

rats

strum

tin

ation of

of f

opte

on of fl

bs,

eas attack

s canis, 8,

inace

almus agy

simil

hl

pf,

hilus c?

rans, 69

superci

era,

ecti

bution

developm

at-flea distin

yllus sty

idn

haga amb

tata

gs

ermi

eron

aceu

ret

es

mouse,

fleas

-fle

icipi

l tube

-Bats

gli

net

tali

illu

zar

her

quirrels

-pigs,

let

kin

ing s

ad

rin

rt,

geh

pter

mon

, Rob

British

ange

aning

-mart

absent fro

a, from b

ea, desc

from Mexican

a, mouth-

, from New

haryn

opsylla

tivor

icipit

lla unipe

r, Empe

an, Emp

sato

Profe

l pal

ium

rum

, 5,

enhoe

tructur

la muscul

?us,

opsyl

hiropt

opsyl

drocl

ssiven

ighi

hian t

a, plagu

bles,

mot

upia

l?, 4

ary pa

orpho

hiropt

key

trem

-part

th,

cle

gen

apod

cobiu

for diss

s syst

erib

ta,

opte

philus be

is classifi

rie

do,

psyll

is riggen

uins

ming f

rel

ryn

geal p

rid

n-fle

gue

and f

Egyp

Lond

al precau

smissio

psyll

cten

nt and C

fin

ans, 4, 19,

id?,

pa

ium,

eas, 1

d man

mice, fle

l gla

tum

charge of b

, flea

-pip

ent

tru

, Mr Charl

y gland

, Book

artin,

isco, pla

llid?, 1

ls,

ed stru

orga

ifferenc

l org

ond

description

of fl

, numbe

llus cun

es 2

nocirc

nite

mata

mac

cilli

's Cath

, metho

oria

Afric

sense

ites

tes

lla brevi

rax

hi, Dr C

che

hosts of

osuru

eras po

late

y tubu

, geograp

bits

la, on Un

relics

ard,

heopis, 11,

sin

ardens, flea

Y JOHN CLAY, M.A. AT

1

1

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CE AND L

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