BEHAVIOR OF ANIMAL ORGANISMS 475 



tion of different types of behavior. A bird building a nest obeys a specific 

 instinct and the nest is stamped by characteristics shared by all the nests 

 of the species to which the bird belongs. At the same time, however, the 

 bird may exhibit individual peculiarities in its construction which are the 

 result of habit and may meet conditions that arise during its construc- 

 tion in such a manner as clearly to indicate the possession of some intel- 

 ligence. Many published observations upon animals are confusing or 

 inconclusive because to what degree different types of activity have 

 entered into the act or the series of acts described has not been made 

 apparent. 



526. Behavior of Lower and of Higher Animals. — It is evident that 

 the behavior of the lowest organisms is dictated by responses to stimuli 

 received from the environment and it is equally clear that as the different 

 phyla pass in review different modes of behavior appear. It is also true 

 that as higher animals have acquired other modes of behavior they have 

 not entirely laid aside those modes of behavior possessed by forms lower 

 than they and that the progression from phylum to phylum up to the 

 highest is a record of accumulation. Any higher animal may show all 

 of the modes of behavior which the animals below it possess, as well, 

 it may be, as a characteristic mode which sets it off as different from those 

 which have preceded. Man, as the highest animal, exhibits all of the 

 different modes. He shows direct response in the iris of the eye and 

 simple reflexes in various parts of the body and exhibits a considerable 

 number of instincts, which have by some been termed innate tendencies. 

 He is also capable of acquiring habits, of using intelligence, and of exer- 

 cising reason. A general principle is that higher modes of behavior are 

 dominant over lower ones. An animal carrying out an instinct will fail to 

 exhibit direct responses which have no relation to the instinct ; intelligence 

 enables an animal to control an instinct; and in man reason may 

 dominate all. 



527. Mind and Consciousness. — These terms are very often used but 

 with varied significance, the application depending upon the point of 

 view of the person using them. Mind and consciousness of a sort have 

 by some persons been attributed even to inorganic matter and by others 

 to plants as well as animals. Within the animal kingdom the line has 

 been drawn at many levels. As has been seen, consciousness of a certain 

 kind is associated with intelligence but it is clearly a question whether or 

 not this is the beginning of consciousness. If one thinks of both con- 

 sciousness and mind as attributes of life, then the conception of both as 

 having been gradually evolved is a logical one. From that point of view 

 both would culminate in man. As a matter of fact, when we compare the 

 consciousness of the savage, who perhaps conceives of nothing beyond the 

 mountain-inclosed valley which is his home and who entertains only 



