Remarks on Impulses Cerebral and Spinal. 525 



mean food for the dog- as "the big- loaf" may mean a cheap meal for 

 a poor man. The original stimulus is physiological here, the final is 

 reflex in result or psychic or aesthetic. 



It is well-known, however, that a trivial sound or sight often 

 suffices to suggest the approach of a familiar friend to even an adult 

 of mature mind. The sense of smell counts for much in mammals, so 

 it is very difficult to tell how much they depend on sight alone. Their 

 general notion of a man seems imperfect or absent. The general 

 notion must be somewhat shadowy for the average man, and even 

 more so for the scientist. The term quadruped is for some reduced 

 to a fiiuisy, shadowy, impression, limited by a pallisade of words. For 

 the young child the term quadruped is apt to arouse a vivid image 

 of some actual animal of the four-footed kind. The operation of 

 suggestion may be mingled association, and association partakes of 

 the nature of a sequence, one act suggesting the next, so that a chain 

 of events may result. It is evident that the anatomical juxtaposition 

 of the centres of action may suggest a sequence, as happens in the 

 brain, or the action of one muscle may set off another. It seems 

 from Sherrington's observations that the bending of the knee causes, 

 by stretching the extensor muscle of the knee, a reflex inhibition of 

 the contraction of that muscle, the muscle assumes, therefore, in 

 consequence, a greater length. The afferent nerve is concerned in 

 this. So a transient contraction may be prolonged owing to the regu- 

 lation of the reflex tonus by the afferent fibres. Similar suggestive 

 reflexes occur in invertebrates (Von Uexkiill in the Sipunculus Eetractor 

 Muscle). The contraction of a frog's gastrocnemius sets another muscle 

 contracting, if the latter's nerve be placed on the first muscle. It is 

 not unusual to find the nerve to a distant muscle going through a 

 proximal one. Having got the sequence it is comparatively easy, in 

 training, to isolate one set of activities by rendering others unnecces- 

 sary or nugatory. It is said that in use of suggestions as between 

 persons, some psychical relationships should have previously existed 

 between them. Thus people brought up in the same family, by the 

 same instructors, and following similar lines of throught, are more 

 susceptible in the case of special suggestions. Suggestion, unobserved 



