286 BIOLOGICAL LECTURES. 



PAGE 



General Considerations 31° 



a. Instinct Precedes Intelligence..: 310 



b. Theories of Instinct 3" 



1. Pure Instinct the Point of Departure 3" 



2. Embryology and the Lamarckian Theory 312 



3. Darwin's Refutation of Lamarck's Theory 313 



4. Weak Points in the Habit Theory 314 



c. Two Demonstrations of the Habit Theory Claimed by Romanes 314 



1. The Instinct of Pouting 316 



2. The Instinct of Tumbling 3'^ 



d. The Habit Theory Losing Ground 3'^ 



e. Hyatt on Acquired Characters 3-° 



/. Preformation the Essence of the Doctrine 321 



The Genetic Standpoint in the Study of Instinct 322 



a. Genealogical History Neglected Z-- 



b. The Incubation Instinct Z-l) 



1. Meaning to be Sought in Phyletic Roots 323 



2. Means Rest and Incidental Protection to Offspring 324 



3. Essential Elements of the Instinct 324 



(i) Disposition to Remain over the Eggs 325 



{2) Disposition to Resist Enemies 325 



(3) Periodicity 3-7 



A Few General Statements 328 



Instinct and Intelligence 33' 



a. Experiment with Hgeons 33- 



b. The Step from Instinct to Intelligence 333 



1. The Passenger Pigeon 334 



2. The Ring-neck Pigeon 334 



3. The Dovecot Pigeon - 335 



4. Results Considered 335 



Animal behavior, long an attractive theme with students 

 of natural history, has in recent times become the centre of 

 interest to im^estigators in the field of pyschogenesis. The 

 study of habits, instincts, and intelligence in the lower ani- 

 mals was not for a long time considered to have any funda- 

 mental relation to the study of man's mental development. 

 Biologists were left to cultivate the field alone, and psycholo- 

 gists only recently discovered how vast and essential were the 

 interests to which their science could lay claim. 



