INSTINCTS AND HABITS IN CHICKS 61 



present state of our knowledge is, Between what kinds of modifi- 

 actions and to what degree is there transfer? Few will dispute 

 the assertion that there may be dispositions preceding and under- 

 lying the acquisition of a particular act which are not identical 

 with those that are at the basis of its actual performance. In- 

 deed the former may no doubt be congenitally present, with or 

 without the actual ability to perform. In a similar manner, of 

 course, one may think of an acquired neurological disposition 

 " predisposing " the individual to certain new activities. And 

 within what range? That is our problem. 



To bring a particular case to a test, two comparable groups 

 of four chicks each were chosen, Group I consisting of chicks 

 nos. 32, 33, 38, and 39, Group II of chicks nos. 34, 35, 36, and 

 40. All the chicks were of the same brood, hatched April 13, 

 1908. None of them had any other training prior to or during 

 the course of these experiments. Uniformity in method was 

 strictly adhered to. The chicks of Group I were given the 

 black-blue training to the point where they made no errors for 

 three successive days, ten trials per day. Then the chicks of 

 both groups entered together into the size training. During the 

 course of the development of each habit one setting of the cards 

 was used for the corresponding trial of all the animals. For 

 example, in the black-blue work, the black card occupied the 

 positions r, 1, r, 1, r, r, 1, 1, r, 1, in each series until an errorless 

 series was reached. At the first setting of the cards — black 

 right, blue left — the chicks of Group I went through one at a 

 time until each animal had to its credit one reaction. Then 

 the cards were exchanged to the second position and the chicks 

 again taken as before. 



As a precaution which seemed ati\4sable, the secondary coil 

 of the inductorium was adjusted at 6 to begin with in the black- 

 blue training, and it was continued thus throughout. In the 

 later size training a shock of the same intensity was employed 

 at the start and at the beginning of the ninth series this was 

 raised to 5.5 en all the chicks alike. 



The order of training was this. When the chicks of Group 

 I were twelve clays old, work was begun with them, and they 

 were trained until they responded errorlessly with a positive 

 reaction to black. On May 11, by which time this group had 

 finished the color work, these animals with those of Group II 



