INSTINCTS AND HABITS IN CHICKS 25 



see the dark basket while sitting in a chair nearby. The peck- 

 ing sounds, as the bills of the chicks struck the bottom of the 

 basket, could be distinctly heard. The usual mouthing noise 

 made by the mandibles could be heard also when one held his 

 ear near the side of the basket. And when I put my hand into 

 the basket, I could feel the heads of the chicks rising and falling 

 in the pecking reaction. 



Before formulating a conclusion let me describe the behavior 

 of no. 71. This chick, in the pecking reaction tests, made the 

 following record from its second to its eleventh day, and then 

 ceased to peck at the grains when brought to the experiment 



table : 



TABLE 4 



Chick no. 71. Dec. 3-12, 1908. Pecking 



Date 3 4 5 6 7 8 9 10 11 12 



Missed 13 2 3 2 2 2 



Struck 6 25 32 26 22 8 17 6 12 43 



Seized 9 5 3 2 3 3 3 1 1 



Swallowed 1 14 10 19 24 39 30 39 37 6 



On Dec. 13 it staggered about in a peculiar way, but did not 

 eat. It would walk directly off the table if not prevented. When 

 tested with water in a watch glass, it drank when the water was 

 held to its bill, but after the dish was moved three or four centi- 

 meters away, it dipped its bill about where the dish had been. 

 Such indications as these convinced me that the animal was 

 blind. For a day or two it was fed by having grain introduced 

 into its bill. Then it was placed in a large dish partly filled 

 with chick food, and on Dec. 16 it began to scratch and eat. 

 For many days thereafter it was regularly placed in the food 

 dish at the feeding hour and procured its meal without assistance. 

 When I entered the room and the rest of the flock ran toward 

 the wires of the cage, no. 71 was often seen approaching, run- 

 ning into obstacles in its path, bobbing up and down in a peculiar 

 variation of the pecking movement, and taking time intermit- 

 tently to scratch in the litter. In this fashion it lived until it 

 was found dead one morning in the drinking vessel. The beha- 

 vior of the chicks in the dark basket, as well as that of this 

 supposedly blind chick, furnish quite clear evidence in refuta- 

 tion of the assumption that chicks do not peck at or eat food 

 when they cannot see it. 



