174 The Unity of the Organism 



of the body." 11 



Even though this statement should prove to be too strong, 

 it certainly contains truth enough to show "the profusion 

 in which common paths exist." 



The functional side of the total reflex system, the struc- 

 tural side of which was visualized by the funnel simile stated 

 above, may be regarded as pretty well presented by certain 

 phenomena known as irradiation. What is meant by this 

 is quite clear, in its general outlines, from the following: 



"The more intense the spinal reflex . . . the wider, as a 

 general rule, the extent to which the motor discharge spreads 

 around its focal area. Thus, as stimulation of the planta 

 causing the flexion-reflex is increased there is added to the 

 flexion of the homonymous hind limb extension of the crossed 

 hind limb, then in the homonymous fore limb extension at 

 elbow and retraction at shoulder, then at the crossed fore 

 limb flexion at elbow, extension at the wrist, and some 

 protraction at shoulder ; also turning of the head toward 

 the homonymous side, and often opening of the mouth, 

 also lateral deviation of the tail. According to circum- 

 stance, especially according to intensity of stimulation, the 

 field of end-effect of the flexion-reflex may vary from a 

 minute field occupying part of a flexor muscle of the knee 

 to a field including musculature in all four limbs and neck 

 and head and tail." 12 



Antagonistic Reflexes in Skeletal Muscle Groups Finally 



Integratwe 



So far what has been said about the interaction between 

 reflexes has dealt only with interactions which are har- 

 monious with one another in various modes of combination. 

 But there are antagonistic or competitive as well as har- 

 monious interactions. These must now receive attention. 

 As an illustration we make use again of the scratching re- 



