THE NERVOUS SYSTEM 65 



The action patterns of each species definitely repre- 

 sent the processes employed by that species for self- 

 perpetuation that is, for adequate defense against 

 enemies, for securing food and for procreation. The 

 action patterns of a turtle, a cobra, a sparrow, a fish or 

 a man are specific for each of those animals, and would 

 be useless if transferred from one to another species. 

 The action patterns of a lion would not do for a deer, 

 nor the patterns of a hawk for a chicken, and were the 

 crossing of such phylogenetically alien species possible, 

 confusion would be the fate of the unfortunate offspring, 

 endowed with the action patterns of each parent. 

 In the case of the offspring of a deer and a lion, for 

 example, the hybrid would be compelled to experience 

 toward every animal a simultaneous desire to attack 

 and to flee. 



The same external agency in an environment com- 

 mon to several organisms may excite vastly different 

 action patterns in the different brains which it stimu- 

 lates. Thus, if the image of a hawk were to fall 

 simultaneously upon the retinas of a chicken, a cow 

 and a boy, there would be created three separate 

 action patterns specific to the phylogenetic experi- 

 ences of these different individuals. The chicken, 

 because chickens have ever been preyed upon by hawks, 

 and only those which flew and flew quickly at the 

 approach of one have survived, will be activated to 

 flight, not because of any power to " reason" about 

 it, but because natural selection has eliminated all 

 chickens which have not automatically fled at the 

 sight of a hawk. The cow, on the contrary, since hawks 

 have exerted no selective influence on it or its species 



