Characters, Hereditary and Acquired. 75 



co-adaptation may thus be reached on the one hand, 

 or how low a degree of utilitarian value on the other. 



Having now stated the general or abstract prin- 

 ciples which I regard as constituting a defence of 

 the Lamarckian factors, so far as this admits of 

 being raised on grounds of physiology, we will now 

 consider a few concrete cases by way of illustra- 

 tion. It is needless to multiply such cases for the 

 mere purpose of illustration. For, on reading those 

 here given, every physiologist will at once perceive 

 that they might be added to indefinitely. The 

 point to observe is, the relation in which these 

 samples of reflex action stand to the general 

 principles in question ; for there is nothing unusual 

 in the samples themselves. On the contrary, they 

 are chosen because they are fairly typical of the 

 phenomena of reflex action in general. 



In our own organization there is a reflex mechanism 

 which ensures the prompt withdrawal of the legs 

 from any source of irritation supplied to the feet. 

 For instance, even after a man has broken his spine 

 in such a manner as totally to interrupt the func- 

 tional continuity of his spinal cord and brain, 

 the reflex mechanism in question will continue to 

 retract his legs when his feet are stimulated by 

 a touch, a burn, &c. This responsive action is 

 clearly an adaptive action, and, as the man neither 

 feels the stimulation nor the resulting movement, 

 it is as clearly a reflex action. The question now is 

 as to the mode of its origin and development. 



I will not here dwell upon the argument from 

 co-adaptation, because this may be done more 

 effectually in the case of more complicated reflex 



