176 The Animal Mind 



ment of the reactions described under these three heads? 

 When a stimulus applied at point a brings about a reaction 

 different from that produced by precisely the same stimulus 

 acting on point b, are the accompanying sensations differ- 

 ent, supposing the animal concerned to be conscious? If 

 they are, the difference must be what has been called a 

 difference in local sign. There is certainly no evidence that 

 space perception is concerned. Space perception in our 

 own experience always involves the simultaneous awareness 

 of several stimuli. But where a single stimulus only is 

 operative, the fact that reaction to it is modified by its 

 location cannot mean that the relations of that location 

 to the location of other stimuli are perceived. The truth 

 is that space perception is so constant a factor in our own 

 experience that we cannot imagine how a single sensation 

 can be modified in connection with change of place of the 

 stimulus, where space perception does not exist. A touch 

 at any point on the skin of a human being is referred to a 

 definite point in a constricted space, tactile and visual; 

 it is given its proper place in a complex of sensations. 

 What modification of it would correspond to its location if 

 it stood alone in consciousness, we cannot now conceive. 



47. Class II: Orienting Reactions; Possible Modes of 

 Producing Them 



Various forces, such as gravity, light, electricity, centrif- 

 ugal force, currents of water and air, are all influences 

 causing certain organisms to bring their bodies into a defi- 

 nite position. Such reactions, involving the direction of 

 the whole body with reference to a continuous force acting 

 upon it, are known as reactions of orientation. There are 

 various ways in which they might conceivably take place. 



