Practical Zoology. For Advanced Level and Intermediate Students

445 Pages·1974·10.636 MB·English

by  C. J. Wallis (Auth.)

PRACTICAL ZOOLOGY
FOR
ADVANCED LEVEL
AND INTERMEDIATE
STUDENTS
BY
C. J. WALLIS, M.A. (Cantab.)
Formerly Master-in-Charge of Biology, University College School,
Biology Master, Highgate School and Principal, Eaton and Wallis,
Tutors
A
LABORATORY MANUAL
Covering the Syllabuses in Zoology of the General Certificate of
Education (Advanced Level) and other Examinations of similar
standard.
SIXTH EDITION
LONDON
WILLIAM HEINEMANN MEDICAL BOOKS LTD
1973
FIRST EDITION, 1935
SECOND EDITION, RE-SET, 1947
THIRD EDITION, 1950
FOURTH EDITION, RE-SET, 1957
IN TWO VOLUMES
Volume I: Zoology
Volume II: Botany
FIFTH EDITION, RE-SET, 1965
FIFTH EDITION OF VOLUME I, RE-SET, 1965
(As a separate book)
SIXTH EDITION, RE-SET, 1974
ISBN 0 433 34704 X
Spanish Edition, 1955
© C. J. WALLIS 1974
By the same author
Practical Botany
Advanced Level Practical Biology
Human Biology
Printed and bound in Great Britain
by R. J. Acford Ltd., Industrial Estate, Chichester, Sussex
FOREWORD TO THE SIXTH EDITION
In the Sixth Edition, the text has been thoroughly revised, enlarged
and brought up to date and to meet the requirements of revised
Examination Syllabuses many additions have been made. These
include the external features and transverse sections of quite a large
number of animals, the dissection of the sea anemone and the locust,
further experiments in physiology and the inclusion of an entirely
new section on Genetics, illustrated by breeding experiments with
Drosophila. Some of the illustrations have been re-drawn, some
taken from my Practical Biology and Human Biology and many
new ones added where it was felt that they would be of assistance
to the student. At the same time the original purpose of the
book of giving adequate instructions, illustrated where necessary, but
avoiding long and tedious reading has been maintained.
I am very grateful to those critics, teachers and students who made
constructive criticisms of the last edition and I have, as far as possible,
embodied their suggestions in the new one.
Once again it gives me great pleasure to record my grateful thanks
to my publishers and to Mr. Owen R. Evans and to Mr. Chris.
Jarvis in particular for the very considerable help given in the
production of the new edition of the book. I am also considerably
indebted to Mr. Frank Price for his assistance in preparing my
pencil drawings for the block-maker and to my wife for her help
with the reading of the proofs and in the tedious process of
compiling the index.
WEST QUANTOXHEAD.
1973. C.J.W.
PREFACE
BIOLOGICAL knowledge, like all scientific knowledge, can be
properly acquired only when it is the result of practical investigation.
The following scheme of practical work has been drawn up in
accordance with the requirements of the syllabuses in Zoology of the
General Certificate in Education (Advanced Level), and of other
examinations of similar standard. Teachers and students can easily
discover what should be omitted by reference to the various examina­
tions syllabuses. This book was originally published as part of a
manual of practical biology for medical students but the plant and
animal biology sections have since been considerably enlarged and
separated into two books, Practical Botany and Practical Zoology,
covering the Advanced Level and similar examination syllabuses in
the separate subjects, and a third book, Practical Biology, suited to
the subject Biology in these examinations has also been published.
Unfortunately, Practical Classes are often unavoidably large and
it is impossible for a great deal of individual attention to be given
to the students. It is in any case desirable that they should learn by
discovering things for themselves, provided they are guided along
the right paths, for by this method they not only absorb facts more
easily but learn to think and work on scientific lines. This was
evident even in the small groups one taught in a tutor's practice in
which students worked individually and not as a class, and in which
there was adequate time to devote to each student in the group.
An attempt has therefore been made to give sufficient directions to
enable the student to proceed with his practical work with a mini­
mum of assistance from the demonstrator. At the same time, the
inclusion of elaborate and unnecessary details which make the reading
long and tedious has been avoided. Simple experiments have been
included in biochemistry and physiology to emphasise the correla­
tion between structure and function. Drawings and diagrams have
been freely inserted when it was considered necessary for the
guidance of the student solely to assist him in his identifications. It is
essential that the student should draw exactly what he sees in his
preparations and that he should not copy diagrams from a book.*
For the sake of practical convenience, this manual is divided into
seven parts—Microscopical Technique, the Variety of Animals—
(Anatomy), Cytology and Histology, Elementary Biochemistry,
Physiology, Genetics and Vertebrate Embryology. Introductory
* Many of the illustrations in this manual are intentionally diagrammatic
or semi-diagrammatic, though several are drawings from specimens.
vii
Vlll PREFACE
notes have been written to each part of the book, giving instructions
peculiar to that part, and appendices have been added which contain
information which it is hoped will be useful to those in charge of
biological laboratories. It is realised that teachers have their own
individual methods in practical work, but there is much that is
common to all. The book is essentially a laboratory manual, and is,
of course, intended for use in conjunction with the usual text-books.
When writing the original book I had much pleasure in expressing
my gratitude to Sir Frederick Gowland Hopkins, O.M., M.B., F.R.S.,
Professor of Biochemistry in the University of Cambridge, to
Professor A. G. Tansley, M.A., F.R.S., Sherardian Professor of
Botany in the University of Oxford and to Dr. L. A. Borradaile,
M.A., Sc.D., Lecturer in Zoology in the University of Cambridge,
for kindly reading through the manuscripts of the Biochemistry,
Plant Biology and Animal Biology sections respectively and for the
many helpful suggestions they made.
I was also deeply indebted to Dr. J. H. Woodger, D.Sc, Reader in
Biology in the University of London and Lecturer in the Middlesex
Hospital Medical School, for reading through the proofs of the
entire First Edition and of the vertebrate types of the Second; and
to Dr. C. L. Foster, M.Sc, Ph.D., also of the Middlesex Hospital
Medical School, for reading through the proofs of the complete
Second Edition. In the course of these readings they made several
invaluable suggestions, the majority of which I was glad to be able
to adopt.
I gratefully appreciate the courtesy of the authors and publishers
of two text-books for permission to use or adapt illustrations
(acknowledged in each instance) from those books.
Lastly, I gratefully acknowledge my indebtedness to my publishers,
and particularly to Mr. Owen R. Evans, for the assistance they have
given me in the production of the various editions of the books.
C. J. WALLIS.
ACKNOWLEDGEMENTS
CLARENDON PRESS. Elements of Zoology, Dakin. Fig. 50.
HENRY HOLT & Co., New York. Development of the Chick, Lillie.
W. WATSON & SONS LTD., Barnet, Herts., for the illustrations of the
microscope. Figs. 6 and 7.
Dr. D. KAY and Dr. J. C. F. POOLE of the Sir WILLIAM DUNN
School of Pathology, Oxford, for the electronmicrograph of an
animal cell, (from the author's Human Biology) Fig. 226.
INTRODUCTION
I. GENERAL DIRECTIONS FOR PRACTICAL
WORK
(1) Cleanliness, tidiness and accuracy are of the utmost impor­
tance. See that all your dissecting instruments are sharp and that
all apparatus is clean before beginning your work. To sharpen a
scalpel an oilstone is necessary. Put a drop of oil on the stone and
push the scalpel, edge foremost, obliquely across the stone. Then turn
the scalpel over and repeat the movement with the other edge.
Alternatively, a circular movement may be made, edge foremost, as
before. Repeat until the blade is sharp. Then draw it once or twice
away from the edge to remove the burr. Scissors must be shar­
pened by an expert. Never use scalpels or scissors for any purpose
other than dissection.
FIG. 1. Sharpening a scalpel.
(2) Read the appropriate subject in your text-book before you
start any practical work.
(3) Read the practical directions carefully before you begin.
(4) Wash, clean, dry and put away all your instruments, apparatus,
etc., when you have finished with them.
(5) In the case of microscopical preparations, it is advisable to
compare your own slides with permanent slides. Always take care
to put the permanent slides back in their proper places in the trays
or boxes; otherwise you (and others) will have difficulty in finding
them on a future occasion.
(6) In the case of dissections, etc., examination of museum speci­
mens is often very helpful.
(7) Finally, throughout your studies try to understand the correlation
between the structure (anatomy) and functions (physiology) of the
various structures, organs and systems.
1
1 PRACTICAL ZOOLOGY
II. GENERAL DIRECTIONS FOR THE KEEPING
OF PRACTICAL NOTEBOOKS
Dissections and Microscopical Preparations
(i) Print the name of the phylum class and animal on top; state
whether it is a dorsal or ventral dissection or an entire specimen, and
in the latter case which view.
If it is a microscopical preparation, state whether it is a longitu­
dinal or transverse section or entire specimen, and whether it is as
seen under the low or high power.
(ii) Write notes of any special directions, e.g., removal or deflection
of organs, method of staining.
(iii) Examine the object carefully before you begin to draw it.
Then make a drawing or diagram in pencil, roughly to scale. Draw
only what you see and draw on a large scale, showing all the necessary
details.
■^N ...-Mucous M embrane
Connective Tissue Layer
Muscular Layer
FIG. 2. Low Power Diagram.
FIG. 3. High Power Drawing of Tissues Indicated in Low Power Diagram,
{From Wallis—Practical Biology)
INTRODUCTION 3
The outline of the animal (or part of it) should be shown where
desirable in order to show the position and relationship of parts.
The use of shading and colours should be kept down to a minimum,
e.g., red for arteries, and blue for veins.
PRINT the names in BLOCK CAPITALS horizontally and join them
to the corresponding parts by straight lines. Avoid crossing these
lines over one another. (The use of letters and a key at the bottom
is not desirable.)
When you have a complicated microscopical structure to draw,
make a diagram (or plan) of the whole structure under the low power
and detailed drawings of small samples of each tissue or of part of
the structure under the high power, all suitably named.
N.B. Never copy drawings or diagrams from textbooks. By doing
so, you learn very little and are therefore wasting valuable time.
Draw only what you see in nature. The illustrations in this book are
intended solely to help the student to find and identify the various
structures and tissues. Many, though not all, of the figures are dia
grammatic or semi-diagrammatic. This is intentional.
III. INSTRUMENTS AND APPARATUS
REQUIRED
By each Student
(1) A set of dissecting instruments in a cloth roll as follows*:—
1 large all-steel scalpel (4-5 cm. blade).
1 medium all-steel scalpel (3-75 cm. blade).
1 small all-steel scalpel (2-5 cm. blade, or less).
[Alternatively, scalpel handles with detachable blades of
various shapes and sizes can be purchased.]
FIG. 4. Useful Scalpel Shapes.
♦Sizes are approximate.
4 PRACTICAL ZOOLOGY
1 dissecting needle.
1 pair of large scissors (12 or 16 cm. overall length).
1 pair of small scissors with fine points (9 or 10 cm. overall
length).
1 pair of large forceps, blunt (12 cm.).
1 pair of small forceps with fine points (10 cm.).
3 or 4 mounted needles.
1 seeker, 1 camel-hair brush, 1 section-lifter.
Other instruments, e.g., bone forceps, may be added as desired.
(2) Large-page practical note-books or files, with plain pages.
The Elementary Biochemistry, Animal Physiology and Genetics can
be conveniently kept together in separate parts of the file, preferably
with some ruled sheets.
(3) A hand-lens (unless supplied by the laboratory).
(4) A microscope (unless supplied by the laboratory). See (7)
below.
(5) The necessary drawing materials and red and blue coloured
pencils.
(6) At least one white coat is desirable unless an old jacket is kept
for laboratory work.
By the Laboratory
In addition to the usual laboratory apparatus, the following will
be needed:—
(1) Dissecting dishes. Rectangular enamel*trays (about 20 x 15
cm.) with black wax composition in the bottom.
(2) Dissecting boards with a rim round the edge (about 60 X 45
cm.) (which may be fitted with hooks or rings at the corners) for
larger animals.
(3) Lenses. Watchmaker's lenses clamped in small retort stands
serve well as dissecting lenses. Larger hand lenses should also be
provided.
(4) Pins, large and small; and awls for large animals.
(5) Thread for ligatures.
(6) Preserving tank for animal material containing 4 per cent.
formaldehyde.
(7) Microscopes (unless provided by the students) with 16 mm.
and 4 mm. objectives, on a triple nose-piece, and No. 2 (X 6) and
No. 4 (xlO) eyepieces. A few better instruments fitted with sub-
stage condensers, Nos. 2 (x6), 4 (x 10) and No. 6 (x 15) eye-pieces,
and a 2 mm O.I. objective are also desirable. A blue filter to fit
below the condenser giving a daylight effect is an advantage when