LIGHT DISCRIMINATION IN THE ENGLISH SPARROW 81 



» 



A chick can acquire a perfect circle- triangle reaction, but con- 

 trol tests show that it has no general idea of circularity in con- 

 trast with triangularity." 



Bingham's conclusion is that " the order of importance of 

 factors in the chicks vision is size, brightness and general illu- 

 mination, and form." 



Porter's 6 work is more directly related to the present inves- 

 tigation since he experimented with English sparrows. He first 

 studied their method of approaching food, and found that they 

 alight some distance from the food and then hop to it. He then 

 studied their rate of learning to open a latch on a food box and 

 of finding their way through a maze. He found that the spar- 

 rows learned quite rapidly by the trial and error method. They 

 exhibited some ability to profit by experience, also to some 

 extent by imitation. Porter then tested the number sense of 

 the English sparrow in the same way that Kinnaman 7 did with 

 monkeys. The birds could not count, but showed some sense 

 of position. When the food glass was covered with colored 

 papers of the standard yellow, blue, red, and green, the birds 

 were able to distinguish the colors. Various forms of food boxes 

 were then used and the food was placed in one of them, the 

 position of which was changed from time to time. This test 

 was made on one bird only — a female. She was unable to dis- 

 tinguish the forms. 



In his later work Porter 8 experimented with English sparrows, 

 vesper sparrows, a cowbird, and a pigeon, attempting to compare 

 the rates and methods of learning of the different birds. In 

 learning the simple maze the vesper sparrow was the slowest. 

 There was little difference between the others. All showed good 

 memories, the cowbird being best. With the puzzle box the 

 sparrow learned most rapidly. Porter then tested the birds for 

 discrimination of three horizontal black lines on a card from a 

 blank card; a card marked with a black diamond from a blank 

 card; and two marked cards from each other. Both the Eng- 



• Porter, J. P. A Preliminary Study of the English Sparrow and Other Birds. 

 Amer. Jour, of Psych., vol. 13, 1904. Page 313. 



' Kinnaman, A. J. Mental Life of Two Macacus Monkeys in Captivity. Amer. 

 Jour, of Psych., vol. 15, 1902. 



« Porter, J. P. Further Studv of the English Sparrow and Other Birds. Amer. 

 Jour, of Psych., vol. 17, 1906. Page 248. 



