14 FREDERICK S. BREED 



C. Pecking 



a. Apparatus and method. — A detailed and prolonged study 

 of the pecking reaction was now attempted. The literature on 

 this topic reveals the fact that the interest in the accuracy of 

 this instinctive activity has been the central one. As suggested 

 before, the accuracy of the reaction became the central interest 

 also in the investigation that is reported in the following pages. 



The apparatus used in these experiments was very simple. 

 A table with a hard polished surface was set near a window where 

 there was good light. To this table the chicks were each morn- 

 ing brought, one at a time, and permitted to eat in a natural 

 way from the surface of a piece of black cardboard about 20 

 cm. wide and 25 cm. long. Carried daily to and from the ex- 

 periment table, the chicks became so habituated to the transfer 

 that the fear response did not enter in to mar the value of the 

 results. From the first the chicks ate from my hand, and soon 

 many of them energetically followed the hand from point to 

 point, gathering up the bits of food as they were dropped. A 

 little later many even gave the " food twitter " while in my 

 hand on the way from the brooder to the table. But it may 

 not be said with accuracy that the chicks became ' ' habituated ' ' 

 to the operation, if at any age without previous trials they sub- 

 mitted, without signs of being disturbed, to the conditions of 

 the experiment. As a fact, they did not thus submit. Animals 

 that had not been used in the pecking tests nor been handled 

 previously in any other experirnent were brought to the table 

 for a control test. They usually struggled when picked up and 

 seemed so disturbed by the situation, when set on the table, 

 that they would not eat at all. This was especially true if they 

 had been allowed to live in the brooder unmolested for two or 

 three weeks. 



For the first tests, which were conducted on the second day, 

 because of the physical weakness of the chicks and their indis- 

 position to eat on the first day, slightly moistened bread was 

 used, of such a consistency that it could be rolled between the 

 fingers into food particles of suitable size. After the second 

 day Cyphers Chick Food, slightly moist, replaced the bread 

 pellets in the tests. This, which was the regular food of the 

 chicks, is a mixture of whole wheat, Kaffir corn, cracked corn, 

 millet, etc. 



