THE SENSATIONS OF ANTS. 507 



Uexkull, the intuitional to the humanizing of animals and all the per- 

 versities of the American " nature-fakers." It is generally easy to 

 class a particular observer according to his temperament and training. 

 The scientist is prone to follow the intellectual method till he ends in 

 rank atomic materialism, but he deserves admiration and sympathy 

 for his consistency and his whole-souled confidence in his method. 

 The intuitionist tends to become a panpsychist and though he may 

 humanize the brute, we must remember that this is not a penal offence 

 and that it does credit to his heart if not to his head. The scholastic 

 will naturally adopt the intellectual method because he is used to work- 

 ing among concepts and abstractions as if they were realities, but if 

 he be a member of some religious body, he will not be averse to using 

 the intuitional method, though in his hands it will be curbed and more 

 or less perverted in the interests of dogma. He who enters on the study 

 of animal behavior in the right spirit will strive to avoid both the nar- 

 rowness of the laboratory worker and the superficial emotionalism of 

 the nature-lover. That he will always adopt the proper attitude between 

 these extremes is not to be expected of human nature, but it is possible 

 to cultivate a critical and catholic spirit. If I decline to join the ranks 

 of those whose only ambition is to describe and measure the visible 

 movements of animals, and am willing to resort to a comparative psy- 

 chology in which inferences from analogy with our own mental proc- 

 esses shall have a place, I do this, not because I believe that the former 

 course would be altogether unfruitful or uninteresting, but because the 

 latter seems to me to promise a deeper and more satisfactory insight 

 into the animal mind. 



In attempting to give a comprehensible account of such complicated 

 phenomena as those of animal behavior, it is necessary to follow the 

 course of the intellect and classify the various processes involved 

 according to certain salient characters. Some authors have dwelt on 

 the simplicity of certain processes, the complexity of others, while 

 other authors have laid greater stress on automaticity and plasticity 

 as differentiae. It is, indeed, convenient to distinguish first, simple 

 responses to sensory stimuli, i. e., reflex behavior ; second, instinctive 

 behavior, which has been referred by some to chains or series of such 

 reactions melodies, so to speak, of which the reflexes are but single 

 notes or chords and third, plastic or modifiable behavior, that is, 

 behavior which is not stereotyped and automatic like the typical reflexes 

 and instincts, but varies adaptively in response to the exigencies of 

 the environment, and is more or less influenced by the previous expe- 

 rience of the individual organism. By many this modifiable activity 

 is supposed to be essentially intelligent. While such a treatment of 



