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