16 FREDERICK S. BREED 



For this, as well as for all other work, the chicks were marked 

 by colored yarns tied on their legs. Each animal thus iden- 

 tified was assigned a number by which it was afterwards known 

 and referred to. 



b. Pecking artificially deferred. — The experiments of Spald- 

 ing,' in which chicks on leaving the shell were blindfolded with 

 little hoods of kept in a flannel bag, have attracted much atten- 

 tion from students of instinct. Spalding sought to .ascertain the 

 facts in regard to instinct. In his time the skeptical were hold- 

 ing " that all the supposed examples of instinct may be — for 

 anything that has yet been observed to the contrary — nothing 

 more than cases of rapid learning, imitation, or instruction." 

 The hooding device was intended to permit the chicks to acquire 

 " enough control over their muscles to enable them to give 

 evidence as to their instinctive power." In other words, the 

 aim was to test the activity of pecking when the factor of acqui- 

 sition was eliminated. The conclusions of Spalding as to the 

 accuracy of pecking, previously referred to, are based on the 

 results of these tests. 



In the similar tests that are reported below, the purpose 

 was to measure the accuracy of the pecking response under 

 circumstances like the above. Not much success was achieved 

 by hooding the chicks. Other means of excluding the light were 

 relied upon. After being tested the chicks were placed in the 

 brooder with the rest of the flock. 



On Dec. lo, 1907, chick no. 8, immediately upon hatching 

 at 1:30 a. m., was blindfolded and transferred to the brooder 

 where it was kept until 10 a. m., Dec. 12, under the curtained 

 hover in a black-lined box at a temperature of 103° F. This 

 box, open at the top, was enclosed in a green flannel bag. 

 At 10 a. m., Dec. 12, the chick was brought carefully to the 

 experiment table for a pecking test. Almost immediately it 

 twice pecked the board upon which it stood. The particular 

 stimulus to the reaction was not apparent. Then followed, in 

 a series, seven reactions, in all of which the chick missed the 

 pellet of bread (rolled as previously described) which elicited 

 them. Seven more pecks at the same crumb followed without 

 hitting it. Then the board on which it stood drew forth two 

 more reactions, when the pecking was interrupted by an awk- 



' Spalding, D. A. . Loc. A, p. 282. 



