PLAY AND INSTINCT. 73 



believe. I trace the connection as follows: A succession 

 of important life tasks is appointed for the adult animal 

 of the higher orders, as for primitive man, some of the 

 principal being as follows: 



1. Absolute control of its own body. Grounded on 

 this fundamental necessity are the special tasks, namely: 



2. Complete control over the means of locomotion 

 for change of place, characteristic of the species, as walk- 

 ing, running, leaping, swimming, flying. 



3. Great agility in the pursuit of prey, as lying in 

 wait, chasing, seizing, shaking. Equal fitness for escap- 

 ing from powerful enemies, as fleeing, dodging in rapid 

 flight, hiding, etc. 



4. Special ability for fighting, especially in the strug- 

 gle with others of the same kind during courtship, etc. 



After the foregoing discussion there can be no doubt 

 that instinct plays a part in all this adaptation for the 

 struggle for life and preservation of the species, so neces- 

 sary in man and other animals. Further — and here 

 I again come into touch with the end of the last chap- 

 ter — it would be entirely in harmony with other phe- 

 nomena of heredity if we found that these instincts ap- 

 pear at that period of life when they are first seriously 

 needed. Just as many physical peculiarities which are 

 of use in the struggle for the female only develop when 

 the animal needs them; just as many instincts that be- 

 long to reproduction first appear at maturity; so the 

 instinct of hostility might first spring up in the same 

 manner only when there is real need for it; and so it 

 might be supposed with other instincts in connection 

 with the related activities. The instinct for flight would 

 only be awakened by real danger, and that of hunting 

 only when the animal's parents no longer nourished 

 it, and so on. What would be the result if this were 



