CHAPTER IX 



ANIMAL BEHAVIOUR 



1. The study of behaviour 2. Restless movements of unicellular 

 animals 3. Organic reactions 4. Trial and error among 

 Protozoa 5. Reflex actions 6. Tropisms 7. Trial move- 

 ments 8. Instinctive behaviour 9. Intelligent behaviour 

 10. Registration and habituation 11. Rational Conduct 12. 

 Artistic skill 13. Spontaneity 14. Purpose. 



1. The Study of Behaviour. By behaviour is meant a 

 correlated or concatenated series of activities in which 

 the animal acts more or. less as a whole, towards some 

 definite result favourable to the continuance and har- 

 mony of its life or towards the welfare of the species. 

 It depends on nervous and muscular functions, but it 

 implies the co-ordination of these in effective agency. 

 It means the accomplishing of the business of life, with 

 its two chief ends, often interacting, of caring for self 

 and caring for others. 



There are many different grades and probably several 

 different lines of behaviour ; thus it is probable that in- 

 stinctive behaviour is on a different line from intelligent 

 behaviour. The difficulty of right interpretation is 

 great ; it is often especially hard to tell how much mental 

 activity is involved. This difficulty is increased when 

 the animals we are observing have a nervous system and 

 sense-organs on a different plan from ours. Another 

 difficulty is that all the available psychological terms 

 are necessarily saturated with human meaning. 



How are we to avoid the over-generosity of Montaigne 

 on the one hand and the over-parsimony of Descartes 

 on the other ? We do not wish to read the man into 

 the beast without critical hesitation, neither do we wish 



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