or the
experiments which were carried on under my daily supervision, I have
left fullest freedom to the authors in the expression of their views.
My own views and my own conclusions from the experiments would not
seldom be in contradiction with theirs, as the authors are sometimes
also in contradiction with one another; but while I, of course, have
taken part in frequent discussions during the work, in the completed
papers my role has been merely that of editor, and I have nowhere
added further comments.

In this work of editing I am under great obligation to Dr. Holt, the
assistant of the laboratory, for his helpful cooeperation.

* * * * *

CONTENTS.

Preface: Hugo Muensterberg ...................................... i

STUDIES IN PERCEPTION.

Eye-Movement and Central Anaesthesia: Edwin B. Holt ........... 3
Tactual Illusions: Charles H. Rieber ......................... 47
Tactual Time Estimation: Knight Dunlap ....................... 101
Perception of Number through Touch: J. Franklin Messenger .... 123
The Subjective Horizon: Robert MacDougall .................... 145
The Illusion of Resolution-Stripes on the Color-Wheel:
Edwin B. Holt .............................................. 167

STUDIES IN MEMORY.

Recall of Words, Objects and Movements: Harvey A. Peterson ... 207
Mutual Inhibition of Memory Images: Frederick Meakin ......... 235
Control of the Memory Image: Charles S. Moore ................ 277

STUDIES IN AESTHETIC PROCESSES.

The Structure of Simple Rhythm Forms: Robert MacDougall ...... 309
Rhythm and Rhyme: R.H. Stetson ............................... 413
Studies in Symmetry: Ethel D. Puffer ......................... 467
The AEsthetics of Unequal Division: Rosewell Parker Angier .... 541

STUDIES IN ANIMAL PSYCHOLOGY.

Habit Formation in the Crawfish, Camburus affinis: Robert
M. Yerkes and Gurry E. Huggins ............................. 565
The Instincts, Habits and Reactions of the Frog: Robert
Mearns Yerkes .............................................. 579

STUDIES IN PSYCHOLOGICAL THEORY.

The Position of Psychology in the System of Knowledge:
Hugo Muensterberg ........................................... 641

PLATES.

OPPOSITE PAGE
Plate I ....................................................... 20
" II ........................