454 ANNUAL, REPORT SMITHSONIAN INSTITUTION, 1918. 



and " Nouvelle Psychologie Animale," as well as for the material 

 contributed by him toward the preparation of the present study. 



CONCLUSION. 



In ordinary speech, the word "instinct"' stands for all the hered- 

 itary and automatic revelations of activity, from simple tropisms 

 to the most complicated outward manifestations of individual mem- 

 ory. Instinctive acts are stereotj^ped, being ever the same when re- 

 sponding to stimuli of the same nature, and almost always adapted 

 to their object, although not resulting from previous experience on 

 the part of the individual. To define them* more precisely is im- 

 possible, for they are varied and complex, overlapping one another 

 and often becoming so confused as to render difficult the tracing of 

 their limits. Nevertheless, we should not place them all on the same 

 level and attribute to them all a common origin. Tropic reactions 

 are due to the properties of living matter, rhythms presuppose an 

 organic memory, and hence a period of education, ancient or recent ; 

 but this apprenticeship is purely mechanical and dependent upon 

 the stimuli that produce it. 



Apprenticeship has its part also in those manifestations of mem- 

 ory belonging to the species which play such an important pait in 

 the behavior of articulates. This kind of memory presents a char- 

 acter of distinct superiority, inasmuch as it was made effective for 

 the race by the distant ancestors of the individual in the guise of a 

 choice between the various possible responses of differential sus- 

 ceptibility. Choice, of a remarkably intellectual nature, is even more 

 noticeable in the instinctive manifestations of individual memory. 

 The animal, endowed with well-developed senses and nervous sys- 

 tem, not only reacts to new necessities by new acts, but associates 

 the stored impressions of new sensations and thereby appropriately 

 directs its further activities. Thus, by an intelligent process, new 

 habits are established, which by heredity become part of the patri- 

 mony of instinct, modifying the latter and constituting elements es- 

 sential to its evolution. Of these instincts acquired through an in- 

 telligent apprenticeship Forel was led to say that they are reasoning 

 made automatic, and it is to them particularly that we may apply 

 the idea of certain biologists that instincts are habits which have 

 become hereditary and automatic. Probably all superior instincts 

 at first had this intellectual quality. This certainly is true of all 

 such as originated from more or less slowly acquired habits ; it seems 

 to be the rule as well with instincts due to mutations. It stands to 

 reason that, whether they result from a sudden psychic change or 

 from a sudden organic modification, these instincts must always be 

 preceded by some intelligent period of education, during which they 



