SIZE AND FORM PERCEPTION 



107 



March 25) the animal did not choose the triangle more than 

 half of the time. With the triangle again upright, the correct 

 reactions returned. Proper responses were secured when the 

 areas were equal, (series 8 and 9, March 28), but when the 

 inscribed triangle was substituted for the standard, the chick 

 was again confused. Series 13, (March 29), another case where 

 the triangle was inverted, gave more decided negative results 

 which were immediately preceded and followed by almost per- 

 fect reactions. As a further test of the effect of inverting the 

 triangle, the inversion was made during a regular series, 15, 

 (March 30). The result of the inversion during tests 5-7 was 

 one right choice, out of 3 chances with an average time of 39 

 seconds. These three special tests were preceded and followed 

 during the same series with perfect tests the time of which 

 averaged less than one-third that of the special tests. 



In connection with these results, I present in detail the be- 

 havior of No. 21 when it was given a 28+ — 63+ discrimina- 



TEST SHEET 



Title of investigation, Form: A 28+ — O 63+ 

 Experimented on, 21 



Harvard Psychological Laboratory, March 18, 1912 

 Record Sheet, 2; Series, 24 



6-4-563. 



