LITERATURE FOR 1914 ON THE BEHAVIOR OF 



VERTEBRATES 



STELLA B. VINCENT 



Chicago Normal College 



VISION 



Mammals. — Both Bingham (3) and Johnson (15) reply to 

 Hunter's criticism of last year, in which he insists that form 

 must be considered as a part of a pattern — that the stimulus 

 object is seen against a visual background. The former urges 

 first, that his apparatus was in a dark room which enabled him 

 to control conditions of setting and second, that a distinction 

 must be made between form and shape, i. e., two similar tri- 

 angles, the one upright and the other inverted, would be alike 

 in form but differ in shape. In his experiments he got a rela- 

 tively low per cent of correct choices when the triangle was 

 inverted; obviously, then, form was not the basis of choice. 

 The perception of shape, for Bingham, is based upon an unequal 

 stimulation of different parts of the retina. 



Johnson argues that to change, as Hunter suggests, the alleys 

 in the Yerkes' experiment box to hollow cylinders or triangles 

 would also change the tactual and probably the olfactory qual- 

 ities. Admitting that the background changes according as the 

 stimulus object occupies the right or the left position respec- 

 tively, he insists that if the stimulus form is as effective in one 

 setting as in the other the conclusion is justified that the animal 

 is really reacting to the constant form difference and disre- 

 garding the variable " pattern " difference. 



The best articles on vision in the year 1914 are those of John- 

 son, beginning his series on Pattern Discrimination in Verte- 

 brates (16), (17). The first paper deals with the standard 

 methods of studying vision, the elementary problems in pattern 

 discrimination and the apparatus and methods. The author 

 defines pattern discrimination as a discrimination between 

 visual fields equal in outline, area and average brightness and 

 differing only in the disposition of their brightness. Four 



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