66 



HAROLD C. BINGHAM 



triangle; and if the chick perceived three-sidedness or triangu- 

 larity on the one hand and circularity on the other hand, there 

 should have been no important modification of its reaction 

 when the triangle was inverted. 



TABLE 9 



Form perception: O 28H A 28+ and O 28H D 28+ 



No. 21. Hatched: February 9, 1912. Sex: 9 



The work on form thus indicated that the chick can discrimi- 

 nate between circles and triangles of equal area, and there are 

 indications of a discrimination between circles and squares of 

 equal area (witness series 21, April 25, table 9, 'and series 23, 

 March 16, table 7), but with the application of control tests 

 we have indications that this discrimination is on some basis 



