CONTENTS OF THE SECOND VOLUME 



SECTION A. THE CHIEF RESULTS OF ANALYTICAL 



BIOLOGY (Continued) 



PART III. ORGANIC MOVEMENTS 



PAGE 



INTRODUCTORY REMARKS ...... 3 



1. THE MOST SIMPLE TYPES OF ORGANIC MOVEMENTS . . 8 



a. THE SIMPLE REFLEX ...... 8 



/S. THE DIRECTIVE MOVEMENTS ..... 9 



Tropism ....... 9 



"Taxis" .... 13 



7. THE WORK OF H. S. JENNINGS. "TRIAL AND ERROR" . 16 



The Resolution of " Taxis " . . . . .17 



The Single Motor Acts. The "Movement at Random " . 20 

 The Modifiability of Single Motor Acts . . .21 



5. CO-ORDINATED MOTIONS . . . . .26 



The Concepts of von Uexkuell . . . .27 



The Classes of Co-ordination . ... 29 



2. INSTINCT .... ... 35 



a. INSOLUBLE PROBLEMS ... 36 



jS. THE ACTUAL PROBLEM. DEFINITIONS . . 38 



y. THE WORK OF J.'LOEB . . . . . .40 



5. THE PROBLEM OF THE STIMULI OF INSTINCTS . . 41 



6. THE PROBLEM OF THE REGULABILITY OF INSTINCTS . . 45 

 f. CONCLUSION ....... 50 



ix 



