THE NERVOUS SYSTEM 19 



of light, even though the fly meets its death 

 thereby. Clearly the movements of the fly are 

 not so like those of a human being, after all. 

 As the test with the artificial light shows, the 

 animal simply seeks light, not freedom. To be 

 sure, in most instances to fly toward the light 

 means to escape, but the insect's behavior is 

 rather in the nature of a reflex than of a cal- 

 culated action, and in that sense lacks intelli- 

 gence. The fly, like many other animals of its 

 own rank, is ordinarily in a state of what may 

 be called balanced reflexes, but after having 

 been especially stimulated by being caught 

 and roughly handled, this balance is greatly 

 disturbed and one set of reflexes, those con- 

 cerned with flight toward the light, becomes 

 supreme. Under such circumstances the fly, 

 without reference to food, drink, or other fac- 

 tor in its environment, rushes headlong at the 

 most considerable light within its range. Of 

 these two states, the one of balanced and the 

 other of unbalanced reflexes, the former is 

 more nearly representative of the condition in 

 man, though at first sight the reverse seems 

 to be true. 



Turning to man, it is evident that, not- 

 withstanding his many powerful and assertive 



