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The Cambridge Manuals of Science and Literature




                               THE FLEA




                      CAMBRIDGE UNIVERSITY PRESS
                       London: FETTER LANE, E.C.
                          C. F. CLAY, MANAGER


[Illustration: LOGO]


                    Edinburgh: 100, PRINCES STREET
             London: H. K. LEWIS, 136, GOWER STREET, W.C.
            WILLIAM WESLEY & SON, 28, ESSEX STREET, STRAND
                       Berlin: A. ASHER AND CO.
                       Leipzig: F. A. BROCKHAUS
                     New York: G. P. PUTNAM’S SONS
             Bombay and Calcutta: MACMILLAN AND CO., LTD.


                         _All rights reserved_




[Illustration:
  _After a drawing by Dr Jordan_
Oriental rat-flea (_Xenopsylla cheopis_ Rothsch.). Male.]




[Illustration; DECORATED FRONT PAGE:

                               THE FLEA

                                  BY

                            HAROLD RUSSELL,
                        B.A., F.Z.S., M.B.O.U.


                        With nine illustrations


                              Cambridge:
                        at the University Press

                                 1913]




                               Cambridge


                      PRINTED BY JOHN CLAY, M.A.
                        AT THE UNIVERSITY PRESS


_With the exception of the coat of arms at the foot, the design on
the title page is a reproduction of one used by the earliest known
Cambridge printer, John Siberch, 1521_




PREFACE


THE aim of this book is to give in plain language some account of a
small, but noteworthy, group of insects. I have avoided, whenever I
could, using the technical terms of zoology. To avoid doing so entirely
is impossible in a book which describes insects in some detail. No
technical term has, I hope, been used without an explanation.

Over thirty years have elapsed since Taschenberg’s German book, _Die
Flöhe_, appeared. Our knowledge has made enormous strides since then.
More species of flea are now known from the British Islands alone
than were then known from the whole world. So far as I am aware, no
book, devoted to what is known about fleas, has ever been published in
English. The statements about these insects in the general text-books
of entomology are frequently antiquated and inaccurate. But there is
a fairly extensive literature on the _Siphonaptera_ scattered through
scientific periodicals mostly in English, German, Italian, Dutch and
Russian. I have given some references in the Bibliography.

The naturalists now living who have devoted any time to the special
study of fleas may almost be counted on one’s fingers. In England there
are Mr Charles Rothschild and Dr Jordan; in the Shetland Islands, the
Rev. James Waterston; in Germany, Taschenberg of Halle and Dampf of
Königsberg; in Russia, Wagner of Kieff; in Holland, Oudemans of Arnhem;
in Italy, Tiraboschi of Rome; in the United States, Carl Baker and a
few others. I have not mentioned medical men who have investigated
fleas in connection with plague.

There are small collections of fleas in the Natural History Museums at
South Kensington (London), Paris, Berlin, Königsberg, Vienna, Budapest,
S. Petersburg and Washington. Of private collections Mr Charles
Rothschild’s at Tring is by far the best in the world. It contains
something like a hundred thousand specimens and is most admirably kept.
I must express profound and sincere gratitude to Mr Rothschild for
having helped me in numberless ways and advised me in many difficulties.

It is well known that the mere mention of fleas is not only considered
a subject for merriment, but in some people produces, by subjective
suggestion, violent irritation of the skin. The scientific study
of fleas has, however, received a great impetus since it has been
ascertained that they are the active agents in spreading plague.
Rat-fleas are of various kinds, and not all fleas will bite man. A
knowledge of the different species has suddenly become useful. The
humble, but ridiculous, systematist with his glass tubes of alcohol for
collecting fleas, his microscopic distinctions, and Latin nomenclature
has become a benefactor of humanity. Some people seem to be practically
immune to the bites of fleas, but even to such persons their visits are
unwelcome. A famous Frenchwoman once declared: “_Quant à moi ce n’est
pas la morsure, c’est la promenade._”

                                                     H. R.

  LONDON,

  _September, 1913_.




CONTENTS


  CHAP.                                                     PAGE

         Preface                                               v

     