ON REFLEXES IN THE SYMPATHETIC SYSTEM 225 



spinal ganglion, the mechanism of a simple true reflex is, taking the 

 matter broadly, the same as the mechanism of a pseudo-reilex. In cach 

 case the impulse passes up one branch of a nerve, spreads to another branch 

 which ends in connection with a nerve-cell, the nerve-cell is excited and an 

 impulse is sent ont to a peripheral structure. If, as some suppose, the 

 central process of asensory nerve is a dendron, a distinction might perhaps 

 be made between axon réflexes and axo-dendron réflexes. 



Further I would point out that it is quite possible that axon réflexes of 

 post-ganglionic fibres may play a considérable part in the transference of 

 impulses in unstriated muscle. The post-ganglionic fibres running to uns- 

 triated muscle undoubtedly branch, and they apparently overlap. It is more 

 than likely that a contraction of a portion of the muscle, excites the nerve 

 fibres of this portion, if so, the impulse would inevitably spread to the other 

 branches of the excited nerves, and thus might cause an adjoining portion of 

 muscle to contract; thus a peristaltic wave would be produccd. Such a 

 pseudo-reflex in post-ganglionic fibres might conveniently be distinguished 

 as irradiation. 



It appears to me that ail réflexes in the sympathetic nervous syslem, 

 isolated from the spinal cord, are axon-reflexes either in pre-ganglionic or 

 in post-ganglionic fibres 



/ y.< ^^rf. 



d5 



