An Introduction to Entomology: Vol. 4 or Elements of the Natural History of the Insects

[Illustration: _Painted by J. J. Masquerier._

  _Engraved by W. T. Fry._

_William Spence, Esq^r., F.L.S._]

            _Published by Longman & C^o. London, July 1825._




                                   AN
                              INTRODUCTION
                                   TO
                              ENTOMOLOGY:

                                   OR
                                ELEMENTS
                                 OF THE
                     _NATURAL HISTORY OF INSECTS_:

                              WITH PLATES.

                  BY WILLIAM KIRBY, M.A. F.R. AND L.S.
                           RECTOR OF BARHAM,
                                  AND
                      WILLIAM SPENCE, ESQ. F.L.S.

                            IN FOUR VOLUMES.
                                VOL. IV.

                            _FIFTH EDITION._

                                LONDON:
                              PRINTED FOR
                 LONGMAN, REES, ORME, BROWN, AND GREEN,
                            PATERNOSTER ROW.

                                 1828.




                       PRINTED BY RICHARD TAYLOR,
                     RED LION COURT, FLEET STREET.




                          CONTENTS OF VOL. IV.

   Letter.                                               Page.

   XXXVII. Internal Anatomy and Physiology of
             Insects. _Sensation_                         1-33

  XXXVIII. Internal Anatomy and Physiology of
             Insects continued. _Respiration_            34-80

    XXXIX. Internal Anatomy and Physiology of
             Insects continued. _Circulation_           81-101

       XL. Internal Anatomy and Physiology of
             Insects continued. _Digestion_            102-126

      XLI. Internal Anatomy and Physiology of
             Insects continued. _Secretion_            127-151

     XLII. Internal Anatomy and Physiology of
             Insects continued. _Reproduction_         152-173

    XLIII. Internal Anatomy and Physiology of
             Insects concluded. _Motion_               174-203

     XLIV. Diseases of Insects                         204-240

      XLV. Senses of Insects                           241-264

     XLVI. Orismology, or Explanation of Terms         265-363

    XLVII. System of Insects                           364-428

   XLVIII. History of Entomology                       429-485

     XLIX. Geographical Distribution of Insects;
             their Stations and Haunts; Seasons;
             Times of Action and Repose                486-527

        L. On Entomological Instruments; and
             the best Methods of collecting,
             breeding, and preserving Insects         528-559

       LI. Investigation of Insects                   560-573

             Appendix                                 575-584
             Authors quoted                           585-602
             Explanation of the Plates                603-614
             Indexes                                  615-683




                                   AN
                              INTRODUCTION
                                   TO
                              ENTOMOLOGY.




                             LETTER XXXVII.

                    _INTERNAL ANATOMY AND PHYSIOLOGY
                              OF INSECTS._

                               SENSATION.


Having given you this full account of the _external_ parts of
insects, and their most remarkable variations; I must next direct
your attention to such discoveries as have been made with regard
to their _Internal Anatomy and Physiology_: a subject still more
fertile, if possible, than the former in wonderful manifestations of
the POWER, WISDOM and GOODNESS of the CREATOR.

The vital system of these little creatures, in all its great features,
is perfectly analogous to that of the vertebrate animals. _Sensation_
and _perception_ are by the means of _nerves_ and a _common sensorium_;
the _respiration_ of air is evident, being received and expelled by
a particular apparatus; _nutrition_ is effected through a _stomach_
and _intestines_; the analogue of the _blood_ prepared by these organs
pervades every part of the body, and from it are secreted various
peculiar substances; _generation_ takes place, and an intercourse
between the sexes, by means of appropriate _organs_; and lastly,
_motion_ is the result of the action of _muscles_. Some of these
functions are, however, exercised in a mode apparently so dissimilar
from what obtains in the higher animals, that upon a first view we are
inclined to pronounce them the effect of processes altogether peculiar.
Thus, though insects respire _air_, they do not receive it by the
_mouth_, but through little orifices in the _sides_ of the body; and
instead of _lungs_, they are furnished with a system of air-vessels