340 



THE AMERICAN NATURALIST [Vol. LIII 



is changed, the movement being reversed, while behavior 

 that does not result in interference or that favors the 

 metabolic processes is continued."^** The primary 

 ''avoiding reaction," in the presence of an unfavorable 

 stimulus, is, of course, comparable with a simple reflex. 

 Its ordinary effect is to remove the organism from the 

 noxious influence. When progressive movements are re- 

 sumed, they occur at random, so far as their direction is 

 concerned, and they may or may not take the organism 

 into favorable surroundings. If they chance so to do, 

 they are continued indefinitely. If not, the reversal of 

 movement occurs as before. Thus while, to the uncrit- 

 ical observer, the organism seems to "seek out" the opti- 

 mum environment, it really reaches this through a series 

 of accidents. This is as true of a cat, releasing itself 

 from an experimental trap, as it is of a paramoecium 

 escaping from a harmful to an optimum water tempera- 

 ture. In the case of the cat we may be tolerably sure 

 that the animal experiences a feeling of discomfort until 

 the means of escape is discovered, and we find it conve- 

 nient, if not inevitable, to say that her restless move- 

 ments are the result of this feeling. In the case of the 

 infusorian, we are much less sure of the conscious ele- 

 ment, though its introduction is permissible as an act 

 of philosophic faith. In theory, most scientists are prob- 

 ably psychophysical parallelists, but in practise it seems 

 necessary at times to use the language of interactionism. 

 In discussing the voluntary movements of a higher ani- 

 mal, any other course would seem pedantic. But in dis- 

 cussing the simple behavior of a lower organism, such 

 language is commonly branded as ''anthropomorphic." 

 Nevertheless, I believe that its oniployment even here is 

 sometimes useful in loicinu' iis to keep in view the essen- 

 tial unity of animal lite. Xo protest is raised by the 

 physiologist when thoroii*;hly pt otozoomorphic language 

 is applied to a vertebrate. Why then should "anthropo- 

 morphic" terminology so shock us in describing the be- 



