CHAPTER VIII 



SPATIALLY DETERMINED REACTIONS AND SPACE 

 PERCEPTION 



45. Classes of spatially determined reactions 



MODIFICATION of the behavior of animals with reference 

 to the spatial characteristics of the forces acting upon them 

 appears at the very beginning of the scale of animal life, and 

 throughout is quite as important as modification with refer- 

 ence to the kind or quality of such forces. It assumes a 

 number of distinct forms. Some of these suggest to us, 

 interpreting them as we must on the basis of our own 

 experience, no conscious aspect at all; they seem rather 

 mechanical effects upon a passive organism. In other 

 cases, it appears possible that the mental process which we 

 know as space perception, involving the simultaneous 

 awareness of a number of sensations consciously referred 

 to different points in space, may accompany the reaction of 

 an animal with reference to the spatial relations of its 

 environment. And sometimes we can only say that differ- 

 ences in the space characteristics of a stimulus may modify 

 the accompanying sensation in some manner which yet 

 apparently does not involve space perception as we know it. 



Our task in the following pages will then be to examine 

 the different ways in which animal behavior is adapted to 

 the spatial characteristics of stimuli, and to ask which of 

 these suggest as their conscious accompaniment some 

 form of space perception. A classification of spatially 



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