xxiv TAlil.H OF CONTENTS. 



PAGE 



II. Sense Perception in Ants 508 



I. Tactile. _'. Olfactory. 3. Gustatory Sensations. 4. Per- 

 ception of Vibrations. Stridulation as a Means of Com- 

 munication. 5. Vision and Phototropism. Reactions to the 

 Ultra-violet and Rontgen Rays. 



III. The Great Importance of the Perceptions of Odor, Touch, 



and Vibrations in the Lives of Ants 517 



CHAPTER XXIX. 



THE INSTINCTIVE BEHAVIOR OF ANTS. 



I. Introductory. Definition of Instinct. Its Ethological, Physio- 

 logical, Psychological and Metaphysical Aspects .... 518 

 II. Instinct from the Objective Point of View 519 



III. The Correlation of Instincts and Structure 521 



I. Instincts as Compound Reflexes. 2. The Centering of In- 

 stinct in Reproduction. 3. Differentiation of Instincts in 

 the Castes. 4. Deferred Instincts. 5. Vestigial and De- 

 cadent Instincts. 6. Diseases of Instinct. The Decay of 

 Ant Colonies Due to Disturbance of their Trophic Balance. 

 7. Regulation in Instinct. 



IV. Instinct Stimuli. Simple and Individualized Stimuli 527 



V. Instinct from the Subjective Point of View. Instinct as 



Divinatory Sympathy 529 



CHAPTER XXX. 



THE PLASTIC BEHAVIOR OF ANTS. 



I. Introductory. Instinct and Intelligence Distinguished. The 



Types of Plastic Behavior 531 



II. Ant Behavior Exhibiting the Ability to Profit by Experience 532 



I. Foraging and homing. 2. Recollection of Xest-mates and 

 Aliens. 3. Communication. 4. Imitation and Cooperation. 

 5. Docility. 



III. The Nature of Memory in Ants 531) 



