xii CONTENTS 



PAGE 



7. Acclimatization to Stimuli ..,.,,..... 207 



8. Reactions to Certain Classes of Stimuli 208 



A. Reactions to Electricity 208 



B. Reactions to Gravity 210 



C. Reactions to Light 212 



9. Behavior of Coelenterates with Relation to Food 216 



A. Food and Respiratory Reactions in Hydra 216 



B. Food Reactions in Medusae 219 



C. Food Reactions in Sea Anemones 221 



10. Independence and Correlation of Behavior of Different Parts of the Body . . 227 



11. Some General Features of Behavior in Coelenterates 230 



Literature 232 



CHAPTER XII 



General Features of Behavior in Other Lower Metazoa 



1. Definite Reaction Forms (" Reflexes ") 233 



2. Reaction by Varied Movements, with Selection from the Resulting Conditions . 238 



3. Modifiability of Behavior and its Dependence on Physiological States . . . 250 

 Literature .........> 259 



PART III 



ANALYSIS OF BEHAVIOR IN LOWER ORGANISMS, WITH A 

 DISCUSSION OF THEORIES 



CHAPTER XIII 

 Comparison of the Behavior of Unicellular and Multicellular Organisms 260 



CHAPTER XIV 



Tropisms and the Local Action Theory of Tropisms . . . -J^' 265 



CHAPTER XV 

 Is THE Behavior of the Lower Organisms composed of Reflexes? . , 277 



CHAPTER XVI 

 Analysis of Behavior in Lower Organisms 



Introductory 283 



I. The Causes and Determining Factors of Movements and Reactions , . . 283 



A. The Internal Factors 283 



(i) Activity does not require Present External Stimulation . , 283 



(2) Activity may change without External Cause .... 285 



(3) Changes in Activity depend on Changes in Physiological States . 286 



