6 THE PHILOSOPHY OF BIOLOGY 



reflex is really a process of much complexity and may 

 involve many other parts and structures than those 

 to which we immediately direct our attention. But 

 leaving aside these qualifications we may usefully 

 consider the general characters of the reflex, regarding 

 it as a common, automatically performed, restricted 

 bodily action, involving receptor organ, central nervous 

 organ, and effector organ. There are certain kinds of 

 external stimuli that continually affect our organs of 

 sense, and there are certain kinds of muscular and 

 glandular activity that occur " as a matter of course," 

 when these stimuli fall on our organs of sense. The 

 emanation from onions or the vapour of ammonia 

 causes our eyes to water ; the smell of savoury food 

 causes a flow of saliva ; and anything that approaches 

 the face very rapidly causes us to close the eyes. 

 Reflexes are, in a way, commonly occurring, purposeful 

 and useful actions, and their object is the maintenance 

 of a normal condition of bodily functioning. 



We dare hardly say that the simple reflex is an un- 

 consciously performed action, although we are not 

 conscious, in the fullest sense of the term, of the 

 reflexes that habitually take place in ourselves. But 

 even in the decapitated frog, which moves its limbs 

 when a drop of acid is placed on its back, something, 

 it has been said, akin to consciousness may flash out 

 and light up the automatic activity of the spinal cord. 

 We must not think of consciousness as that state of 

 acute mentality which we experience in the perform- 

 ance of some difficult task, or in some keenly apprec- 

 iated pleasure, or in some condition of mental or bodily 

 distress ; it is also that dimly felt condition of normality 

 that accompanies the satisfactory functioning of the 

 parts of the bodily organism. But this dim and 

 obscure feeling of the awareness of our actions is easily 



