The Dancing Mouse by Robert M. Yerkes

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[Illustration: DANCING MICE--SNIFFING AND EATING.]

THE ANIMAL BEHAVIOR SERIES. VOLUME I

THE DANCING MOUSE

A Study in Animal Behavior

BY

ROBERT M. YERKES, Ph.D.
INSTRUCTOR IN COMPARATIVE PSYCHOLOGY IN HARVARD
UNIVERSITY

The Cartwright Prize of the Alumni Association of the College of
Physicians and Surgeons, Columbia University, was awarded, in 1907, for an
Essay which comprised the first twelve chapters of this volume.

1907

IN LOVE AND GRATITUDE
THIS BOOK IS DEDICATED TO
MY MOTHER

PREFACE

This book is the direct result of what, at the time of its occurrence,
seemed to be an unimportant incident in the course of my scientific work--
the presentation of a pair of dancing mice to the Harvard Psychological
Laboratory. My interest in the peculiarities of behavior which the
creatures exhibited, as I watched them casually from day to day, soon
became experiment-impelling, and almost before I realized it, I was in the
midst of an investigation of their senses and intelligence.

The longer I observed and experimented with them, the more numerous became
the problems which the dancers presented to me for solution. From a study
of the senses of hearing and sight I was led to investigate, in turn, the
various forms of activity of which the mice are capable; the ways in which
they learn to react adaptively to new or novel situations; the facility
with which they acquire habits; the duration of habits; the roles of the
various senses in the acquisition and performance of certain habitual
acts; the efficiency of different methods of training; and the inheritance
of racial and individually acquired forms of behavior.

In the course of my experimental work I discovered, much to my surprise,
that no accurate and detailed account of this curiously interesting animal
existed in the English language, and that in no other language were all
the facts concerning it available in a single book. This fact, in
connection with my appreciation of the exceptional value of the dancer as
a pet and as material for the scientific study of animal behavior, has led
me to supplement the results of my own observation by presenting in this
little book a brief and not too highly technical description of the
general characteristics and history of the dancer.

The purposes which I have had in mind as I planned and wrote the book are
three: first, to present directly, clearly, and briefly the results of my
investigation; second, to give as complete an account of the dancing mouse
as a thorough study of the literature on the animal and long-continued
observation on my own part should make possible; third, to provide a
supplementary text-book on mammalian behavior and on methods of studying
animal behavior for use in connection with courses in Comparative
Psychology, Comparative Physiology, and Animal Behavior.

It is my conviction that the scientific study of animal behavior and of
animal mind can be furthered more just at present by intensive special
investigations than by extensive general books. Methods of research in
this field are few and surprisingly crude, for the majority of
investigators have been more deeply interested in getting results than in
perfecting methods. In writing this account of the dancing mouse I have
attempted to lay as much stress upon the development of my methods of work
as upon the results which the methods yielded. In fact, I have used the
dancer as a means of exhibiting a variety of methods by which the behavior
and intelligence of animals may be studied. As it happens the dancer is an
ideal subject for the experimental study of many of the problems of animal
behavior. It is small, easily cared for, readily tamed, harmless,
incessantly active, and it lends itself satisfactorily to a large number
of experimental situations. For laboratory courses in Comparative
Psychology or Comparative Physiology it well might hold the place which
the frog now holds in courses in Comparative Anatomy.

Gratefully, and with this expression of my thanks, I acknowledge my
indebtedness to Professor Hugo Muensterberg for placing at my command the
resources of the Harvard Psychological Laboratory and for advice and
encouragement throughout my investigation; to Professor Edwin B. Holt for
valuable assistance in more ways than I can mention; to Professor Wallace
C. Sabine for generous aid in connection with the experiments on hearing;
to Professor Theobald Smith for the examination of pathological dancers;
to Miss Mary C. Dickerson for the photographs of dancing mice which are
reproduced in the frontispiece; to Mr. Frank Ashmore for additional
photographs which I have been unable to use in this volume; to Mr. C. H.
Toll for the drawings for Figures 14 and 20; to Doctors H. W. Rand and C.
S. Berry for valuable suggestions on the basis of a critical reading of
the proof sheets; and to my wife, Ada Watterson Yerkes, for constant aid
throughout the experimental work and in the preparation of this volume.

R. M. Y.

CAMBRIDGE, MASSACHUSETTS,

August, 1907.

CONTENTS

LIST OF ILLUSTRATIONS

LITERATURE ON THE DANCING MOUSE

CHAPTER I

CHARACTERISTICS, ORIGIN, AND HISTORY

Peculiarities of the dancing mouse--Markings and method of keeping record
of individuals--The dancer in China and Japan (Kishi, Mitsukuri, Hatai)--
Theories concerning the origin of the race: selectional breeding; the
inheritance of an acquired character; mutation, inheritance, and
selectional breeding; pathological changes; natural selection--Instances
of the occurrence of dancers among other kinds of mice--Results of
crossing dancer with other kinds of mice.

CHAPTER II

FEEDING, BREEDING, AND DEVELOPMENT OF THE YOUNG

Methods of keeping and caring for dancers--Cages, nest-boxes, and
materials for nest--Cleansing cages--Food supply and feeding--Importance
of cleanliness, warmth, and pure food--Relations of males and females,
fighting--The young, number in a litter--Care of young--Course of
development--Comparison of young of dancer with young of common mouse--
Diary account of the course of development of a typical litter of dancers.

CHAPTER III

BEHAVIOR: DANCE MOVEMENTS

Dancing--Restlessness and excitability--Significance of restlessness--
Forms of dance: whirling, circling, and figure-eights--Direction of
whirling and circling: right whirlers, left whirlers, and mixed whirlers--
Sex differences in dancing--Time and periodicity of dancing--Influence of
light on activity--Necessity for prolonged observation of behavior.

CHAPTER IV

BEHAVIOR: EQUILIBRATION AND DIZZINESS

Muscular coordination--Statements of Cyon and Zoth concerning behavior--
Control of movements, orientation, equilibration, movement on inclined
surfaces, climbing--The tracks of the dancer--Absence of visual
dizziness--Comparison of the behavior of the dancer with that of the
common mouse when they are rotated in a cyclostat--Behavior of blinded
dancers (Cyon, Alexander and Kreidl, Kishi)--Cyon's two types of dancer--
Phenomena of behavior for which structural bases are sought: dance
movements; lack of response to sounds; deficiency in equilibrational
ability; lack of visual and rotational dizziness.

CHAPTER V

STRUCTURAL PECULIARITIES AND BEHAVIOR

The functions of the ear--Structure of the ear of the dancer as described
by Rawitz, by Panse, by Baginsky, by Alexander and Kreidl, and by Kishi--
Cyon's theory of the relation of the semicircular canals to space
perception--Condition of the auditory organs--Condition of the
equilibrational organs--Condition of the sound-transmitting organs--The
bearing of the results of anatomical investigations upon the facts of
behavior.

CHAPTER VI

THE SENSE OF HEARING

Experiments on hearing in the dancer made by Rawitz, by Panse, by Cyon, by
Alexander and Kreidl, by Zoth, and by Kishi--Hearing and the voice--
Methods of testing sensitiveness to sounds--Results of tests with adults--
Importance of indirect method of experimentation--Results of tests with
young--The period of auditory sensitiveness--Individual differences.

CHAPTER VII

THE SENSE OF SIGHT: BRIGHTNESS VISION

What is known concerning sight in the dancer--Brightness vision and color
vision--Methods of testing brightness vision, the visual discrimination
apparatus--Motives for discrimination and choice--Punishment versus reward
as an incentive in animal experiments--Hunger as an incentive--An electric
stimulus as an incentive--Conditions for brightness vision tests--
White-black vision--Evidence of preference--Check experiments--Conclusion.

CHAPTER VIII

THE SENSE OF SIGHT: BRIGHTNESS VISION (_Continued_)

The delicacy of brightness discrimination--Methods of testing the dancer's
ability to detect slight differences in brightness--Results of tests with
gray papers--Relation of intensity of visual stimuli to the threshold of
discrimination--Weber's law apparatus and method of experimentation--
Results of Weber's law tests--Practice effects, the training of vision--
Description of the behavior of the dancer in the discrimination box
experiments--Modes of choice: by affirmation; by negation; by comparison--
Evidence of indiscriminable visual conditions.

CHAPTER IX

THE SENSE OF SIGHT: COLOR VISION

Does the dancer see colors?--The food-box method of testing color vision--
Waugh's food-box method--Results of tests--Tests by the use of colored
papers in the visual discrimination box--Yellow-red vision--Blue-orange
vision--Brightness vision _versus_ color vision--Brightness check
tests--Green-blue vision--Violet-red vision--Conclusions.

CHAPTER X

THE SENSE OF SIGHT: COLOR VISION (_Continued_)

The use of color filters--Testing color vision by the use of transmitted
light--Green-blue vision--Green-red vision--Blue-red vision--Stimulating
value of different portions of the spectrum--Does red appear darker to the
dancer than to us?--Conclusions concerning color vision--Structure of the
retina of the dancer and its significance.

CHAPTER XI

THE ROLE OF SIGHT IN THE DAILY LIFE OF THE DANCER.

Sight and general behavior--Behavior of blinded dancers--Experimental
tests of ability to perceive form--Visual guidance in mazes--Following
labyrinth paths in the dark--The relative importance of visual, olfactory,
and kinaesthetic stimuli--Conditions for the acquisition of a motor
habit--Conditions for the execution of an habitual act.

CHAPTER XII

EDUCABILITY: METHODS OF LEARNING

The modifiability of behavior--Educational value of experimental studies
of modifiability--Methods: the problem method; the labyrinth method; the
discrimination method--Relation of method to characteristics of animal--
Simple test of the docility of the dancer--Lack of imitative tendency--
Persistence of useless acts--Manner of profiting by experience--Individual
differences in initiative.

CHAPTER XIII

HABIT FORMATION: THE LABYRINTH HABIT

The labyrinth method--Problems--Preliminary tests--Comparison of the
behavior of the dancer in a maze with that of the common mouse--Evolution
of a labyrinth method--Records of time and records of errors--Simple and
effective method of recording the path--Curves of habit formation--Regular
and irregular labyrinths--Points for a standard labyrinth--Values and
defects of the labyrinth method.

CHAPTER XIV

HABIT FORMATION: THE DISCRIMINATION METHOD

Quantitative _versus_ qualitative results--Motives--Precautions--
Preference--Results of systematic habit-forming experiments--Curves of
habit formation--Meaning of irregularity in curve--Individual
differences--Comparison of curves for discrimination habits with those for
labyrinth habits--Averages--The index of modifiability as a measure of
docility--Reliability of the index.

CHAPTER XV

THE EFFICIENCY OF TRAINING METHODS

Importance of measuring the efficiency of educational methods--Rapidity of
learning and permanency of modifications wrought by training--Results of a
study of the efficiency of discrimination methods--Comparison by means of
indices of modifiability--Number of tests per series versus number of
series--Efficiency as measured by memory tests.

CHAPTER XVI

THE DURATION OF HABITS: MEMORY AND RE-LEARNING

Measures of the permanency of modifications in behavior--The duration of
brightness and color discrimination habits--The relation of learning to
re-learning--Can a habit which has been lost completely be re-acquired
with greater facility than it was originally acquired?--Relation of
special training to general efficiency--Does the training in one form of
labyrinth aid the dancer in acquiring other labyrinth habits?

CHAPTER XVII

INDIVIDUAL, AGE, AND SEX DIFFERENCES IN BEHAVIOR

Individual peculiarities in sensitiveness, docility, and initiative--The
relation of docility to age--The individual result and the average--How
averages conceal facts--Sex differences in docility and initiative--
Individual differences of motor capacity which seem to indicate
varieties--Is the dancer pathological?

CHAPTER XVIII

THE INHERITANCE OF FORMS OF BEHAVIOR

Characteristics of the race--Inheritance of the tendency to whirl in a
particular way--Tests of the inheritance of individually acquired forms of
behavior.

INDEX

ILLUSTRATIONS

Dancing Mice--sniffing and eating _Frontispiece_

FIGURE

1. Color patterns of dancers. Record blanks

2. Double cage, with nest-boxes and water dishes

3. Double cages in frame

4. Photographs of dancers climbing (After Zoth)

5. Tracks of common mouse (After Alexander and Kreidl)

6. Tracks of dancer (After Alexander and Kreidl)

7. The inner ear of the rabbit (Retzius)

8. The membranous labyrinth of the ear of the dancer (After Rawitz)

9. Same

10. Same

it. Model of the ear of the dancer (After Baginsky)

12. Ear of the dancer (After Kishi)

13. Ear of the dancer (After Kishi)

14. Discrimination box

15. Ground plan of discrimination box

16. Nendel's gray papers

17. Weber's law apparatus

18. Food-box apparatus

19. Waugh's food-box apparatus

20. Color discrimination apparatus

21. Ground plan of color discrimination apparatus

22. Cards for form discrimination

23. Labyrinth B

24. Labyrinth B on electric wires

25. Labyrinth A

26. Curves of habit formation for labyrinth B

27. Plan of labyrinth C, and path records

28. Labyrinth D

29. Curve of learning for white-black discrimination, twenty individuals

30. Curve of learning for white-black discrimination, thirty individuals

31. Curve of habit formation for labyrinth D

32. Curves of learning and re-learning

33. Plasticity curves

LITERATURE ON THE DANCING MOUSE

1. ALEXANDER, G. UND KREIDL, A. "Zur Physiologie des Labyrinths der
Tanzmaus." _Archiv fuer die gesammte Physiologie_, Bd. 82: 541-552.
1900.

2. ALEXANDER, G. UND KREIDL, A. "Anatomisch-physiologische Studien ueber
das Ohrlabyrinth der Tanzmaus." II Mittheilung. _Archiv fuer die gesammte
Physiologie_. Bd. 88: 509-563. 1902.

3. ALEXANDER, G. UND KREIDL, A. "Anatomisch-physiologische Studien ueber
das Ohrlabyrinth der Tanzmaus." III Mittheilung. _Archiv fuer die
gesammte Physiologie_, Bd. 88: 564-574. 1902.

4. BAGINSKY, B. "Zur Frage ueber die Zahl der Bogengaenge bei japanischen
Tanzmaeusen." _Centralblatt fuer Physiologie_, Bd. 16: 2-4. 1902.

5. BATESON, W. "The present state of knowledge of colour-heredity in mice
and rats." _Proceedings of the Zooelogical Society of London_, Vol. 2:
71-99. 1903.

6. BREHM, A. E. "Tierleben." Dritte Auflage. Saugetiere, Bd. 2: 513-514.
1890.

7. BREHM, A. E. "Life of Animals." Translated from the third German
edition of the "Tierleben" by G. R. Schmidtlein. Mammalia, p. 338.
Marquis, Chicago. 1895.

8. CYON, E. DE. "Le sens de l'espace chez les souris dansantes
japonaises." _Cinquantenaire de la Societe de Biologie_ (Volume
jubilaire). p. 544-546. Paris. 1899.

9. CYON, E. VON. "Ohrlabyrinth, Raumsinn und Orientirung." _Archiv fuer
die gesammte Physiologie_, Bd. 79: 211-302. 1900.

10. CYON, E. DE. "Presentation de souris dansantes japonaises." _Comptes
rendus du XIII Congres International de Paris, Section de
physiologie_, p. 160-161. 1900.

11. CYON, E. VON. "Beitraege zur Physiologie des Raumsinns." I Theil. "Neue
Beobachtungen an den japanischen Tanzmaeusen." _Archiv fuer die gesammte
Physiologie_, Bd. 89: 427-453. 1902.

12. CYON, E. DE. "Le sens de l'espace." Richet's "Dictionnaire de
physiologie," T. 5: 570-571. 1901.

13. DARBISHIRE, A. D. Note on the results of crossing Japanese waltzing
mice with European albino races. _Biometrica_, Vol. 2: 101-104. 1902.

14. DARBISHIRE, A. D. Second report on the result of crossing Japanese
waltzing mice with European albino races. _Biometrica_, Vol.2:
165-173. 1903.

15. DARBISHIRE, A. D. Third report on hybrids between waltzing mice and
albino races. _Biometrica_, Vol. 2: 282-285. 1903.

16. DARBISHIRE, A. D. On the result of crossing Japanese waltzing with
albino mice. _Biometrica_, Vol 3: 1-51. 1904.

17. GUAITA, G. v. "Versuche mit Kreuzungen von verschiedenen Rassen der
Hausmaus." _Berichte der naturforschenden Gesellschaft zu Freiburg i.
B_., Bd. 10: 317-332. 1898.

18. GUAITA, G. v. "Zweite Mitteilung uber Versuche mit Kreuzungen von
verschiedenen Hausmausrassen." _Berichte der naturforschenden
Gesellschaft zu Freiburg i. B_., Bd. 11: 131-138. 1900.

19. HAACKE, W. "Ueber Wesen, Ursachen und Vererbung von Albinismus und
Scheckung und ueber deren Bedeutung fuer vererbungstheoretische und
entwicklungsmechanische Fragen." _Biologisches Centralblatt_, Bd.
15: 44-78. 1895.

19a. HUNTER, M. S. "A Pair of Waltzing Mice." _The Century Magazine_,
Vol. 73: 889-893. April, 1907.

20. KAMMERER, P. "Tanzende Waldmaus und radschlagende Hausmaus."
_Zooelogische Garten_, Bd. 41: 389-390. 1900.

21. KISHI, K. "Das Gehoerorgan der sogenannten Tanzmaus." _Zeitschrift
fuer wissenschaftliche Zooelogie_, Bd. 71: 457-485. 1902.

22. LANDOIS, H. "Chinesische Tanzmaeuse." _Jahresbericht des Westfaehschen
Provinzial-Vereins_, Munster, 1893-1894: 62-64.

22a. LOSE, J. "Waltzing Mice." _Country Life in America_, September,
1904. p. 447.

23. PANSE, R. Zu Herrn Bernhard Rawitz' Arbeit: "Das Gehoerorgan der
japanischen Tanzmaeuse." _Archiv fuer Anatomie und Physiologie_,
Physiologische Abtheilung, 1901: 139-140.

24. PANSE, R. "Das Gleichgewichts- und Gehoerorgan der japanischen
Tanzmaeuse." _Muenchener medicinische Wochenschrift_, Jahrgang 48, Bd.
I: 498-499. 1901.

25. RAWITZ, B. "Das Gehoerorgan der japanischen Tanzmaeuse." _Archiv fuer
Anatomie und Physiologie_, Physiologische Abtheilung, 1899: 236-243.

26. RAWITZ, B. "Neue Beobachtungen ueber das Gehoerorgan japanischer
Tanzmaeuse." _Archiv fuer Anatomie und Physiologie_, Physiologische
Abtheilung, 1901, Supplement: 171-176.

27. RAWITZ, B. "Zur Frage ueber die Zahl der Bogengaenge bei japanischen
Tanzmaeusen." _Centralblatt fuer Physiologie_, Bd. 15: 649-651. 1902.

28. SAINT-LOUP, R. "Sur le mouvement de manege chez les souris."
_Bulletin de la Societe Zooelogique de France_, T. 18: 85-88. 1893.

29. SCHLUMBERGER, C. "A propos d'un netzuke japonais." _Memoires de la
Societe Zooelogique de France_, T. 7: 63-64. 1894.

30. WELDON, W. F. R. Mr. Bateson's revisions of Mendel's theory of
heredity. _Biometrica_, Vol. 2: 286-298. 1903.

31. ZOTH, O. "Ein Beitrag zu den Beobachtungen und Versuchen an
japanischen Tanzmaeusen." _Archiv fuer die gesammte Physiologie_, Bd.
86: 147-176. 1901.

32. ANONYMOUS. "Fancy Mice: Their Varieties, Management, and Breeding."
Fourth edition. London: L. Upcott Gill. No date.

CHAPTER I

CHARACTERISTICS, ORIGIN, AND HISTORY

The variety of mouse which is known as the Japanese dancing or waltzing
mouse has been of special interest to biologists and to lovers of pets
because of its curious movements. Haacke in Brehm's "Life of Animals" (7
p. 337)[1] writes as follows concerning certain mice which were brought to
Europe from China and Japan: "From time to time a Hamburg dealer in
animals sends me two breeds of common mice, which he calls Chinese
climbing mice (Chinesische Klettermaeuse) and Japanese dancing mice
(Japanische Tanzmaeuse). It is true that the first are distinguished only
by their different colors, for their climbing accomplishments are not
greater than those of other mice. The color, however, is subject to many
variations. Besides individuals of uniform gray, light yellow, and white
color, I have had specimens mottled with gray and white, and blue and
white. Tricolored mice seem to be very rare. It is a known fact that we
also have white, black, and yellow mice and occasionally pied ones, and
the Chinese have profited by these variations of the common mouse also, to
satisfy their fancy in breeding animals. The Japanese, however, who are no
less enthusiastic on this point, know how to transform the common mouse
into a really admirable animal. The Japanese dancing mice, which perfectly
justify their appellation, also occur in all the described colors. But
what distinguishes them most is their innate habit of running around,
describing greater or smaller circles or more frequently whirling around
on the same spot with incredible rapidity. Sometimes two or, more rarely,
three mice join in such a dance, which usually begins at dusk and is at
intervals resumed during the night, but it is usually executed by a single
individual."

[Footnote 1: The reference numbers, of which 7 is an example, refer to the
numbers in the bibliographic list which precedes this chapter.]

As a rule the dancing mouse is considerably smaller than the common mouse,
and observers agree that there are also certain characteristic
peculiarities in the shape of the head. One of the earliest accounts of
the animal which I have found, that of Landois (22 p. 62), states,
however, that the peculiarities of external form are not remarkable.
Landois further remarks, with reason, that the name dancing mouse is ill
chosen, since the human dance movement is rather a rhythmic hopping motion
than regular movement in a circle. As he suggests, they might more
appropriately be called "circus course mice" (22 p. 63).

Since 1903 I have had under observation constantly from two to one hundred
dancing mice. The original pair was presented to the Harvard Psychological
Laboratory by Doctor A.G. Cleghorn of Cambridge. I have obtained
specimens, all strikingly alike in markings, size, and general behavior,
from animal dealers in Washington, Philadelphia, and Boston. Almost all of
the dancers which I have had, and they now number about four hundred, were
white with patches, streaks, or spots of black. The black markings
occurred most frequently on the neck, ears, face, thighs, hind legs, about
the root of the tail, and occasionally on the tail itself. In only one
instance were the ears white, and that in the case of one of the offspring
of a male which was distinguished from most of his fellows by the
possession of one white ear. I have had a few individuals whose markings
were white and gray instead of white and black.

The method by which I was able to keep an accurate record of each of my
dancers for purposes of identification and reference is illustrated in
Figure 1. As this method has proved very convenient and satisfactory, I
may briefly describe it. With a rubber stamp[1] a rough outline of a
mouse, like that of Figure 1 A, was made in my record book. On this
outline I then indicated the black markings of the individual to be
described. Beside this drawing of the animal I recorded its number,
sex,[2] date of birth, parentage, and history. B, C, and D of Figure 1
represent typical color patterns. D indicates the markings of an
individual whose ears were almost entirely white. The pattern varies so
much from individual to individual that I have had no trouble whatever in
identifying my mice by means of such records as these.

[Footnote 1: For the use of the plate from which this stamp was made, I am
indebted to Professor W.E. Castle, who in turn makes acknowledgment to
Doctor G.M. Allen for the original drawing.]

[Footnote 2: I have found it convenient to use the even numbers for the
males and the odd numbers for the females. Throughout this book this usage
is followed. Wherever the sex of an individual is not specially given, the
reader therefore may infer that it is a male if the number is even; a
female if the number is odd.]

All of my dancers had black eyes and were smaller as well as weaker than
the albino mouse and the gray house mouse. The weakness indicated by their
inability to hold up their own weight or to cling to an object curiously
enough does not manifest itself in their dancing; in this they are
indefatigable. Frequently they run in circles or whirl about with
astonishing rapidity for several minutes at a time. Zoth (31 p. 173), who
measured the strength of the dancer in comparison with that of the common
mouse, found that it can hold up only about 2.8 times its own weight,
whereas the common white mouse can hold up 4.4 times its weight. No other
accurate measurements of the strength, endurance, or hardiness of the
dancer are available. They are usually supposed to be weak and delicate,
but my own observations cause me to regard them as exceptionally strong in
certain respects and weak in others.

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