62 The Animal Mind 



rather on the spatial than on the qualitative side. The 

 sense quality of pain we naturally think of as the ac- 

 companiment of the negative reaction in its more violent 

 forms, given to a stimulus that is injuring the organism. 

 Organic and kinesthetic sensations are hard to trace in 

 the lower animals; for animals whose structure differs 

 widely from our own, the qualities of these two classes 

 must remain beyond the power of our imagination. That 

 differences in physiological condition such as are produced 

 by hunger, satiety, or fatigue involve differences of ac- 

 companying organic sensation in the consciousness of the 

 animal manifesting them is possible. Kinaesthetic sen- 

 sations, as we shall see, are apparently concerned in the 

 processes whereby many animals have learned to traverse 

 a labyrinth path. 



The three classes of sensation whose existence in the 

 animal mind can be most satisfactorily traced are the 

 chemica l sense, under which ^mell p .pfj _ taste belong s the 

 senseloCheajing, and the sense of sig ht. To the study of 

 these the following chapters will be devoted. Since the 

 manifestations of the chemical sense in the lowest forms of 

 animals consist chiefly in a differentiation of response to 

 food and to mechanical stimulation, the contact sense or 

 sense of touch will, in discussing these forms, be considered 

 along with the chemical sense. 



