76 HEREDITY AND SELECTION IN SOCIOLOGY 



just as the impulse to flee from man becomes in time instinctive 

 in the walrus. In both cases the instinct is due, not to 

 " inherited habit," but to natural selection. 



The question may be raised as to whether instinct may not 

 be the result of tradition. In some cases this may be true. 

 In the case of the walrus, mentioned above, it is possible to main- 

 tain that the instinct of flight from man is the result of tradition 

 rather than of natural selection. The example of the older 

 animals, which have themselves been pursued by hunters, may 

 be followed by the younger ones, and these may hand on the 

 tradition of fear of man to their progeny, and so forth, through- 

 out several generations. Thus the instinct of flight may finally 

 appear as constant as if it were a result of long and rigid selection. 

 The instinct to fly in general may likewise be a traditional 

 instinct with insects ; but the same nervous mechanism which 

 acts in this case acts also in the case of approaching danger, 

 when flight is, although unknown to the insect, an indispensable 

 necessity to the species. This instinct to fly from an approaching 

 object is of such vital importance for the existence of the species 

 that it cannot be left to simple tradition. In this case it would 

 remain purely individual, incapable of hereditary transmission, 

 and would have to be learned afresh by imitation in each indi- 

 vidual life ; whereas a fundamental instinct, bound up with the 

 very life of the species, must needs be an inborn ancestral charac- 

 teristic of the species, and dependent upon natural selection. 

 For this reason it is probable that the instinct of flight in the 

 walrus is also a fundamental racial instinct, not the result of 

 mere tradition, but of natural selection. 



We have examined the Lamarckian theory in regard to here- 

 ditary transmission of mutilations, of disease, and of instinct, 

 the three sets of cases generally supposed to constitute its 

 strength. We have seen that, in regard to the transmission 

 of mutilations, it is based on no single scientific fact ; in regard 

 to the transmission of disease, we have seen that criticisms of 



