246 EDWIN G. BORING 



a side which, it would seem, is more strongly excited than that 

 from which it moves away under weak, diffuse illumination. 

 It is not necessary to assume a two-process consciousness in- 

 volving an opposition of the conscious representatives of the 

 excitations upon both sides. The opposition may be entirely 

 non-conscious, so that the reaction of the animal may be regarded 

 as merely the physical resultant of two unequal, opposing 

 forces, a resultant which might be represented in consciousness 

 by a single process, just as the resultant of red and green stimu- 

 lation of the retina is accompanied by a single sensation of the 

 quality aroused by the predominant component. 



If we push this analogy further, we are led to assume a qual- 

 itative difference between the process accompanying the response 

 toward the left and that accompanying the response toward 

 the right, — just as there exists a qualitative difference between 

 red and green. Such a consciousness of " leftness " and " light- 

 ness," involving, as it does, an elementary two-quality form of 

 spatial consciousness, it is, nevertheless, not necessary to assume. 

 To be sure, the substitution by the planarian under continued 

 strong stimulation of a reaction toward one side for that toward 

 the other appears to constitute a modification of behavior that 

 comes at least as near implying consciousness as does any other 

 form of behavior in the planarian; 11 and, if we assume that the 

 change in response is the direct result of continued stimulation, 

 we may expect it to be paralleled by a change in conscious 

 content, say, from a simple "get-away-to-the-right " process to 

 a simple " get-away-to-the-left " process. If, however, we 

 accept the notion that the change of response is due merely to 

 muscular compensation, it is no longer necessary to postulate 

 two avoiding reactions aroused by the same stimulus nor the 

 resulting spatial differentiation. If there is a conscious con- 

 comitant to the negative reaction, it may r be no more than a 

 single "get-away" process. 



We may deny the .spatial character of the change of content 

 accompanying the reversal of reaction, and yet not deny the 

 change itself. On our simplest hypothesis, we assume a mus- 

 cular contraction as the result of great fatigue in other muscles, — 

 a co-ordination as complex as that involved in the ordinary 



11 In unpublished work by Professor Bentley and the writer the " very charac- 

 teristic " gripping reaction, forming "-an integral part of the normal food reac- 

 tion," described by Pearl, loc. cit., pp. G24ff., has not been observed. 



