330 WALTER S. HUNTER 



in his own work set up, in one case, a discrimination between a 

 triangle of 28 sq. cm. and a circle of the same area. When the 

 triangle was inverted, the animal failed in its reactions. He 

 concludes that the indications are " that this discrimination is 

 on some other basis than form." 3 Farther down on the same 

 page, he says ''form in the stricter sense has been found to have 

 no discriminative value." 



So far as I know, Bingham is the only one who has put the 

 problem just that way, i.e., form vs. retinal distribution of 

 light. The conception of "form" to which I desire to call atten- 

 tion is perhaps hinted at in Lashley's article. Lashley tested 

 white rats (Ex. 5), on the discrimination of two lines each 2 x 

 60 mm. One line was horizontal and the other vertical. Posi- 

 tive results were obtained. The author refers continually to 

 this as a discrimination of forms. The assumption underlying 

 it all is undoubtedly that although for the experimenter the 

 illumined spaces were identical rectangles for the animal the 

 situation presented was one of different forms. Lashley does 

 not develop the point, nor does Bingham, who writes later, 

 refer to the former author's data — although Lashley cannot be 

 interpreted as using the term "form" in Bingham's sense. (Lash- 

 ley's article may not have appeared when Bingham's went to 

 press.) The stimuli used by Lashley were identical forms from 

 Bingham's point of view. Now what I wish to insist upon is 

 this : Animals do not discriminate form in the abstract sense 

 in which Bingham uses that term. Both series of experiments 

 referred to above are concerned with patterns, not forms. I 

 would go farther and present the hypothesis that all animals 

 below man have only a more or less crude pattern vision and 

 that this probably applies also to a varying period of human 

 childhood. 



This hypothesis presents itself for consideration under two 

 forms: (1) Its validity under artificial experimental conditions 

 such as are found in the experiment boxes used by the inves- 

 tigators above cited. (2) Its validity under conditions of a 

 natural habitat. Let us take up these points in the order men- 

 tioned. (1) In problem boxes such as those described by Lash- 

 ley and Bingham (these are of the same general nature as those 

 recommended for the study of size and form by Yerkes and 



3 Op. cit., p. 110. 



