Characters, Hereditary and Acquired. 73 



and collective origin in some very high degree of 

 efficiency, if natural selection has been the only 

 principle concerned in afterwards perfecting the 

 mechanism. For it is self-evident that a reflex action, 

 from its very nature, cannot admit of any great 

 differences in its degrees of adaptation : if it is to 

 work at all, so as to count for anything in the struggle 

 for life, it must already be given in a state of working 

 efficiency. So that, unless we invoke either the 

 doctrine of " prophetic types " or the theory of sudden 

 creations, I confess I do not see how we are to explain 

 either the origin, or the development, of a reflex 

 mechanism by means of natural selection alone. 



Lastly, in the third place, even when reflex 

 mechanisms have been fully formed, it is often beyond 

 the power of sober credence to believe that they now 

 are, or ever can have been, of selective value in the 

 struggle for existence, as I will show further on. And 

 such cases go to fortify the preceding argument. For 

 if not conceivably of selective value even when com- 

 pletely evolved, much less can they conceivably have 

 been so through all the stages of their complex 

 evolution back to their very origin. Therefore, sup- 

 posing for the present that there are such cases of 

 reflex action in nature, neither their origin nor their 

 development can conceivably have been due to 

 natural selection alone. The Lamarckian factors, 

 however, have no reference to degrees of adaptation, 

 any more than they have to degrees of complexity. 

 No question of value, as selective or otherwise, can 

 obtain in their case : neither in their case does any 

 difficulty obtain as regards the co- adaptation of 

 severally useless parts. 



