Biology Dictionary 8th ed. (1990) WW

609 Pages·1990·19.34 MB·English

and then -P!z-&sor of zooiogy a? I3lIke&~
cidieg

-LcvmiEm iLEd 5-om i 970 TO 19w was I3zkznJI-of the?
!2mqmays
i3esemh
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cIksdge* He

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4

was .
eI?Aae&a
Faiow o
f
rheR.cm3.i sm i
n
195X
F
-.

d awarded an hmo,zzy duct0~mteb-y
theutim-

t. <

sity of Zppsala in 197. He died in May 19?9 just
after 5nk&irg work on the sever&h
edition
ofthis dic-
~~-~~~
rioq,
-~
~~
~~

Ii4idxd
ET-
T
was born in Worcesxershkx
in

1943. He gained a mst sass Ho-
iuc. i n

Bioiogy and Botany from the University of Western
Ontario in 1966 and a PhD. in Phycoiogy
and

Freshwarer
Ecology from the University of Bristol in
C-L-2 :- Ii-%?A TT-
1- - -
1.. - -
Ifi 177u. Pit; TIas - lTr&kss&Boianpar
- - - - ---%.

the Umversity of Aknxta from 1981. after having
been both Assistant Professor and Associate Profes-
sor in the same department since 1970. He has had
numerous papers published on lhis investigative re-
searches into lakes and rivers and has acted as a
consdtam for many
oqpmzations.
He is currentiy

engaged in mearch concerning
effecis of ciimatiz

change upon the pastsr
Lhistor)- of selecred
_4lberm

lakes. He lives in Edmonron
-kth
his =ife 2nd two

children.

54, L. Johnsoc
raughr zoolog at Birmingha~m
TL‘nix-er-

sit)- for some years. aod rLvarchrd
on respiratrion of
invertebrates and 011 ce-rve
dqeoeration. She ther,

researched on selection md training of medical stu-
dents aI University College London and on perceptual

disorders in cerebral palsied children at Guy’s
Hospital, and became Reader in Architectural Educa-
tion at University College London. She then worked
with the new clinical course in the Cambridge medi-
cal school. Publications include Anatomy of Judge-
ment, Perceptual and. Visuo-Motor Disorders in Cere-
bral Palsy, Aims and Techniques of Group Teaching,
and (with P. M. Terry) Talking to Learn. M. L.
Johnson died in 1984.

Michael Thain was born in Hampstead in 1946 and
educated at University College School and Keble
College,
Oxford,
graduating
in
Zoology
and
gaining

a Diploma in Human Biology. After an. intro-
duction to History and Philosophy of Science at
University
College
London,
he
graduated
in
Philos-
ophy from Birkbeck College, London, in 1983, and is
currently
studying
History
of
Technology
at
Imperial

College, London. In 1969 he joined the staff of _
Harrow School, where he was Head of Biology for
eleven years and is now Head of General Studies

\
and in charge of the school’s conservation area. He
is collaborating on a- Dictionary of Zoology, also
for Penguin, and lives in Harrow with his wife and
two children.

I

THE NEW PENGUIN
THE NEW PENGUIN
DlCTl6NARYOF
DlCTl6NARYOF

L O G Y ,-
L O G Y ,-

M. Abercrombie
M. Abercrombie
M. Hickman
M. Hickman
M. L. Johnson
M. L. Johnson
M. Thain
M. Thain

0

EIGHTH EDITION
EIGHTH EDITION

I

I
-

PENGUIN BOOKS
I

::

F

P E N G U I N B O O K S
i

Published by the Penguin Group
Penguin Books Ltd, 27 Wrights Lane, London W8 5TZ, England
Penguin Books USA Inc., 375 Hudson Street, New York, New York 10014, USA
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Penguin Books Australia Ltd, Ringwood, Victoria, Australia
Penguin Books Canada Ltd, 2801 John Street; Markham, Ontario, Canada L3R 1 B4
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Penguin Books (NZ) Ltd, 182-190 Wairau Road, Auckland 10, New Zealand

Penguin Books Ltd, Registered Qffices: Harmondsworth, Middlesex, England

s
First published as The Penguin Dictionary of Biology, 1951
Second edition 1954
’

Third edition 1957

’
Fourth edition 1961
Fifth edition 1966
Sixth edition 1973

Seventh edition 1980

Eighth edition, entiRed
The New penguin Dictionary of Biology, 1990
3 5 7 9 1 0 8 6 4 2

Copyright 0 M. Abercrombie, C. J. Hickman and M. L. Johnson, 1951,1954,
1957,

1961, 1966,1973,
1980

Copyright 0 Michael Thain, the Estate of M. Abercrombie,
the Estate of C. J. Hickman and the Estate of
M. L. Johnson, 1990
All rights reserved

The acknowledgements on pages ix-x constitute an extension of this copyright page

Printed in England by Clays Ltd, St Ives plc

Filmset in 9 on lO+pt Monophoto Times

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Except in the United States of America,
this book is sold subject to the condition
that it shall not, by way of trade or otherwise,
be lent, re-sold, hired out, or otherwise circulated
P’

without the publisher’s prior consent in any form of
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binding or cover other than that in which it is
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published and without a similar condition

including this condition being imposed

IF”

on the subsequent purchaser

I

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FOR KATEY AND AVRIL, AND MARGARET
/

h

.-

PREFACE TO EIGHTH EDITION

In the first major revision of this work for some years, changes were
overdue to both its form and content if we were to ensure its continu-
ance as a valuable reference book for school and undergraduate work.
While remaining within the tradition set by the previous authors, we
I

provide more of the encyclopaedic
type of entry, in particular for terms

central to theory and for those describing a phenomenon or process

:

central to much else in the discipline. These articles and the extensive

;

cross-referencing
of
most
entries
will
not
please
everyone,
least
of
all

1

those who consult this dictionary merely as a lexicon. For brevity’s
sake we have dispensed with many definite and indefinite articles, but

i

have tried to keep the result grammatical.
1

F

It may be argued against us that some head words rarely turn up in

:

.
E

the literature. In defence, terms such as arms race and cost of meiosis
are included here not because they are particularly common in the
literature but because they represent convenient headings under which
to include important material that would have been difficult to place
elsewhere
without
over-stretching
another
entry.
In
a
few
cases,
indeed

[
F

on the very first page, several entries with a mutual bearing on one
another have been brought together under a single head word or
phrase, we hope for interest as well as convenience. Where this occurs,
all included subterms are separately listed, directing the reader to larger
entries. Terms in small capitals indicate where the reader might choose
to pursue related matters raised by an entry; for a cross-referencing role
lies firmly in this dictionary’s tradition. Some will argue that this
detracts from what little aesthetic appeal the work may have; but cross-
references frequently provide information which it was the authors’
hope should be read, although by no means all terms with separate
entries are given small capitals. Italicized terms either indicate subdivis-
ions of an entry or those terms with a particular tendency to be found
associated with the head word. Others have less explicit claim to
emphasis, but were simply considered worth stressing.

I-

We have endeavoured throughout to include genuinely informative

material, in addition to stating -the obvious. Advanced readers will
share with us the common frustration of finding too little interesting
information in dictionary entries, and we have sought to avoid that.
Each entry could have been written in many ways, and although we
have never knowingly side-stepped the thorny problems that many
attempts
at
definition
pose,
we
must
often
have
oversimplified
through
ignorance. However, it did not seem possible to do justice to such terms
as gene, classification and species, without including some of the philoso-
phical issues they raise. Likewise, it seemed at times inappropriate to
exclude a little historical information. To this extent we hope to have
promoted the view that biology is not an isolated discipline, and that its

i

-__l;
.__.
----%-J

. . .

VIII

natural links with other fields of inquiry deserve explicit recognition
and study in their own right.
It is a pleasure to record here the many people who have given advice

during the preparation of this dictionary, both in formulating entries
and in reviewing sections of manuscript. Pupils at Harrow and students
at the University of Alberta, Edmonton, have provided valuable criti-
cism as consumers. Particular thanks for advice and comments also go
to Richard Burden, ‘Michael Etheridge, John Hoddinott, Stephanie
Holliday, John Imeson, Bill Richmond, Chris Stringer, Dick Vane-
Wright, Dale H. Vitt and two very helpful referees who chose to
remain anonymous. Eileen Michie did splendid copy-editing work.
It goes without saying that any errors which remain are the sole
responsibility of the authors, who would welcome corrections and
suggestions
for
improvement.
The dictionary has isolated us from our families, sometimes at rather
critical periods, and it is a special pleasure to be able to recognize their
patience and forbearance, particularly Katey and Avril, and Margaret,
to whom the work is dedicated.

M.H.
M.T.
February 1990

Il‘

ACKNOWLEDGEMENTS
FOR
FIGURES

Some of the original illustrations and/or labelling may have been

slightly
altered.

Alberts, B., et al.: Molecular Biology of the Cell (1st edn), Garland

(1983). Figs. 3a, 3b, 6a, 6b, 8, 9, 14, 20,-29,44, 60.

Austin, C. R., and Short, R. V.: Reproduction in Mammals, Book 2:
Embryonic and Fetal Development (2nd edn), CUP (1982). Figs. 16,
55.
Barrington, E. J. W.:s Invertebrate Structure and Function (2nd edn),

Nelson (1979). Figs. 17a, 17b, 17~.

Chapman, R. F.: The Insects (2nd edn), Hodder & Stoughton (1971).
Fig. 49.
Charig, A.: A New Look at the Dinosaurs, British Museum (Natural
History) (1979). Fig. 63.
Cohen, J.: Reproduction, Butterworths (1977). Figs. 62a, 62b.
Freeman, W. H., and Bracegirdle, B.: An Advanced Atlas of Histology,
Heinemann (1976). Fig. 24.
Frobisher, M., et al.: Fundamentals ofMicrobiology
(9th edn), Harcourt
Brace Jovanovich (1974). Figs. 3c, 30.
Goodenough,
U.: Genetics (3rd edn), Holt-Saunders (1984). Fig. 38.
Grimstone, A. V., Harris, H., and Johnson, R. T.: Prospects in Cell
Biology, The Company of Biologists Ltd, Cambridge (1986). Fig. 37.

Hartman,
P. E., and Suskind, S. R.: Gene Action, Viking Penguin Inc.
(1965). Fig. 10.
Hopkins, C. R.: Structure and Function of Cells, Harcourt Brace

Jovanovich (1978). Figs. 4a, 4b, 5a, 5b, 5c, 5d.

Hughes, G. M.:
Comparative Physiology of Vertebrate Respiration,
Harvard University Press (1963). Figs. 23b,
23~.

Katz, B.: Nerve, Muscle and Synapse, McGraw-Hill, Inc. (1966). Fig.
35.
Kingley, J. S.: Outlines of Comparative Anatomy of Vertebrates, -The
Blakiston
Company
(McGraw-Hill
Book
Company) (1928)
with
permission of McGraw-Hill, Inc. Fig. 23a.
Landsborough Thompson, A. (ed.): A New Dictionary of Birds, British
Ornithologists’ Union (1964). Figs. 18a,
18b.

Lehninger, A. L.: Biochemistry (2nd edn), Worth (1975). Figs. 12a,
12b,

25b, 26,28, 33, 51, 64.

Lewis, K. R., and John, B.: The Matter of Mendelian Heredity (2nd

edn), Longman (1972). Fig. 42(ij.

Mather,
K.: Genetical Structure of Populations, Chapman and Hall
(1973). Figs. 21a, 21b.
May, R. M. (ed.): Theoretical Ecology (2nd edn), Blackwell (1981).
Table 5.

X

Roberts, M. B. V.: Biology: A Functional Approach (3rd edn), Nelson
Roberts, M. B. V.: Biology: A Functional Approach (3rd edn), Nelson
(1982). Figs. 54a, 54b.
(1982). Figs. 54a, 54b.
Romer, A. S.: The Vertebrate Body (5th edn), Holt-Saunders (1977).
Romer, A. S.: The Vertebrate Body (5th edn), Holt-Saunders (1977).
Figs. 2, 52b, 53.
Figs. 2, 52b, 53.
Slack, J. M. W.: From Egg to Embryo, CUP (1983). Fig. 22.
Slack, J. M. W.: From Egg to Embryo, CUP (1983). Fig. 22.
Staines, N., Brostoff, J., and James, K.: Introducing Immunology, Gower
Staines, N., Brostoff, J., and James, K.: Introducing Immunology, Gower
Medical (1985). Figs. 41,43.
Medical (1985). Figs. 41,43.

Szalay, F. S., and Delson, E.: Evolutionary History of the Primates,
Szalay, F. S., and Delson, E.: Evolutionary History of the Primates,

I Academic Press (1979). Fig. 34.
I Academic Press (1979). Fig. 34.
Tortora, G. J., and Anagnostokos, N. P.: Principles ofAnatomy and
Tortora, G. J., and Anagnostokos, N. P.: Principles ofAnatomy and
Physiology (4th edn), Harper and Row (1984). Figs. 25a,
27,32,40,
Physiology (4th edn), Harper and Row (1984). Figs. 25a,
27,32,40,

47, 50, 52a, 57,61a.
47, 50, 52a, 57,61a.

Watson, J. D.: Molecular Biology of the Gene (3rd edn), Benjamin/
Watson, J. D.: Molecular Biology of the Gene (3rd edn), Benjamin/
.

Cummings (1976). Fig. 39.
Cummings (1976). Fig. 39.

A-BAND.
See
STRIATED
MUSCLE.

ABAXIAL.
(Of a leaf surface) facing away from stem. Compare AD-

AXIAL.
\

ABDOMEN. (1) Vertebrate body region containing viscera (e.g. in-

testine, liver, kidneys) other than heart and lungs; bounded anteriorly
in mammals but not other classes by a diaphragm. (2) Posterior
arthropod trunk segments, exhibiting,~~~~~~~~ in insects, but not
in crustaceans.

ABDUCENS
NERVE. Sixth vertebrate CRANIAL NERVE. Mixed, but

mainly motor, supplying external rectus eye-muscle.

ABERRANT
CHROMOSOME
BEHAVIOUR. Departures from normal

mitotic and meiotic chromosome behaviour, often with a recognized
genetic basis. Includes (1) achiasmate meiosis, where chiasmata fail
to form (e.g. in Drosophila spermatogenesis; see SUPPRESSOR MU -

T A TI 0 N); (2) amitosis, where a dumb-bell-like constriction separates
into two the apparently ‘interphasellike’, but often highly polyploid,
ciliate macronucleus prior to fission of the cell; (3) chromosome
extrusion or loss, as with X-chromosomes in egg maturation of
some
parthenogenetic
aphids
(see
s E x
D E T E R M I N A T I 0 N);
a n d

. in Drosophila where gynandromorphs may result; but notably in
some midges (e.g. Miastor, Heteropeza) where paedogenetic larvae
produce embryos whose somatic cells contain far fewer chromo-
somes than
GERM LINE cells, owing to selective elimination during

1 cleavage (see WEISMANN). In some scale insects, males and females
develop from fertilized eggs, but males are haploid because the
entire paternal chromosome set is discarded at cleavage (see HE T -

EROCHROMATIN,
PARASEXUALITY,
GYNOGENESIS);
(4)
meiotic

drive, where a mutation causes the chromosome on which it occurs
to be represented disproportionately often in gametes produced by
meiosis, as with the segregation distorter (SD) locus of Drosophila;
mutants homozygous for the SD allele are effectively sterile; (5)
premeio tic
chromosome
doubling
(see
A u T 0 M I x I s);
(6)
E N D 0 -

MITOSIS, where chromosomes replicate and separate but the nucleus
and cell do not divide; (7) POL Y TEN Y, where DNA replication occurs
but the strands remain together to form thick, giant chromosomes.

ABIOTIC. Environmental features, such as climatic and ED A PH I c
factors, that do not derive directly from the presence of other
organisms. See BIOTIC.