Reflexes, Instincts, and Intelligence 637 



similarly performed by all the members of the same more or less restricted 

 group of animals; but which are subject to variation, and to subsequent 

 modification under the guidance of experience. Intelligent behavior may be 

 distinguished roughly from instinctive behavior by being the outcome and 

 product of experience; by involving usually the element of choice among a 

 number of possible responses; by revealing a capacity to act with special 

 reference or adaptation to new circumstances, and by revealing an individ- 

 uality in dealing with the complex conditions of a variable environment. 

 In reflex and instinctive behavior the animal acts like a piece of well-made 

 and adequately wound clockwork; in intelligent behavior the clockwork 

 seems protean; it is a plastic machine capable of swift adaptation to exter- 

 nal needs. 



In the brief discussion of insect behavior constituting this chapter, I shall 

 assume a general acceptance of the above definitions of and distinctions 

 among reflex, instincts, and intelligence — these definitions being substan- 

 tially in the words of C. L. Morgan, the thorough-going Darwinian student 

 of animal behavior; and I shall consider the particular illustrations of insect 

 behavior taken up in the light of the classification established by the defini- 

 tions. It is needless to say that the actual character and conditions of the 

 behavior in each case are the essential things to keep in mind in any anal}!- 

 ical discussion of the subject, and not the uncertain, if more or less conve- 

 nient, attempt to classify the cases. 



From Loeb's point of view all animal responses differ only in degree, 

 not at all in kind, and are all, from simplest to most complex, rigidly me- 

 chanical reactions to actual physico-chemical stimuli. From the anthropo- 

 morphic naturalists' point of view on the contrar)'. a mystic capacity, 

 incident only to living matter, of reason and psychical functioning reveals 

 itself in almost all animal behavior, and the sluggish movements of the star- 

 fish toward the water or around its prey are due to appreciation and likes 

 and that intelligent determination familiar as factors in human action. 

 Finally, from the point of view of the churchman naturalist the distinction 

 between the springs of human behavior and "animal " behavior is as sharp 

 as the assumed distinction between the possession of soul and spiritual ex- 

 istence on the part of man and the absence of these attributes in tiie lower 

 animals. Our point of view will be, however, as stated ; that fairly safe one 

 between the rigid mechanicalism of the tropism believers and the mysticism 

 of the believers in a divinely endowed creature of psyche as contrasted with 

 a long series of unfortunate soulless brutes. 



While the interested observation and recognition of insect habits and 

 behavior has long occupied naturalists and poets, the careful, thoroughly 

 checked and guarded study of this behavior has been curiously wanting. 

 And only in very recent years has anything like experimental investigation 



