NERVES AND THE REACTIONS OF ORGANISMS 223 



The sense impression produced by a touch on the skin travels 

 along the axon of an afferent nerve. This disturbance is 

 shunted off, or reflected, through a synapse into one or more 

 efferent neurons to the corresponding muscles and results in 

 a movement more or less suitable for the occasion. But this 

 shunting takes place in the spinal cord or in the lower 

 parts of the brain that do not involve feeling or consciousness 

 or willing. No matter how useful or purposeful such actions 

 appear to be, we must understand that reflexes do not represent 

 the animal's desires or intentions. In many animals, including 

 man, these reflexes may be called forth during sleep or during 

 unconsciousness produced by ether or chloroform. Under such 

 circumstances it is certain that the movements are not intended, 

 not " done on purpose." 



