INSTINCTS AND HABITS IN CHICKS 73 



struggle, it was brought back to the entrance box for the next 

 trial. The record of its behavior found in table 25 is made sub- 

 ject to the irregularity reported below. The result of this 

 persistence test is the same as that in its last training series. 

 It would be difficult to reach any trustworthy conclusion in 

 regard to the persistence of the small-large habit from the 

 data at hand, for these data have to be considered together 

 with a certain defect in the adjustment of the apparatus. When 

 the persistence tests of nos. 24 and 25 were made, these chicks 

 were so large that they had to squeeze through the smaller 

 opening. For the test of no. 34 the small opening was made 

 slightly larger and a dimension of the larger opening altered 

 to preserve similarity of shape. 



TABLE 26 



The Rapidity of Modification and its Permanence 



Black-Blue Training 



Persistence 



Chick Age Sex Trials Errors Interval R W 



16 12 F 100 28 30 10 



17 12 F 60 20 30 10 



18 12 F 100 35 30 8 2 



19 12 F 60 28 30 7 3 



20 12 M 60 19 30 10 



32 12 F 30 10 32 10 



33 12 M 70 20 30 10 



38 12 M 100 25 31 4 6 



39 12 F 70 20 30 9 1 



Index of modifiability 72 . 2 



For the assistance it may be to others in estimating the value 

 of these tests of the persistence of modifications, it should be 

 stated that some of the chicks were in poor physical condition 

 when the tests were made. In the confinement of the laboratory 

 few chicks remained in normal physical condition after eight to 

 twelve weeks. 



It is interesting to study the above data on the persistence of 

 habit in connection with the number of trials and errors in the 

 original training series to see if any correlation exists between 

 the rapidity of acquisition and its permanence or retention. In 

 table 26 the necessary items are set side by side. One often 

 hears the pedagogical byword, " Come easy, go easy." This 



