120 FLETCHER, COWAN AND ARLITT 



the boxes on which they were placed increased, finally refusing 

 to jump from boxes thirty-nine inches in height. 



We undertook to determine the height at which our chicks 

 would refuse to jump and whether this height differed for normal 

 and alcohol chicks. The subjects were six seven-day old chicks, 

 three normal and three alcohol, and seven fifteen-day old chicks, 

 two normal and five alcohol. 



The chicks were placed on stands above the box in which 

 the other chicks were kept. The distance from the top of the 

 stand to the floor of the box increased gradually from 10.7 cm. 

 to 171.5 cm. The alcohol chicks w r ere not placed on stands 

 of greater height than 171.5 cm., as it was feared that they 

 might be injured in jumping to the box. The chicks were 

 allowed to rest and feed for thirty seconds after each return 

 to the box. 



There was little difference in the reactions of normal and 

 alcohol six-day old chicks (see Table 5), but in the case of the 

 fifteen-day old chicks the difference in behavior of the normal 

 and alcohol chicks was marked. The normal chicks hesitated 

 for longer and longer intervals as the height of the stands in- 

 creased, waiting for over five minutes before jumping from a 

 stand 106 cms. above the box. Though repeatedly pushed they 

 would not jump from stands above this height. The alcohol 

 chicks jumped with little or no hesitation. No. 32 would not jump 

 from a stand 134 cm. in height, but Nos. 21, 28 and 22 jumped 

 with almost no hesitation from stands 171.5 cm. above the box. 



The following tables present in detail the results of the ex- 

 periments with heights: 



TABLE 5 



Chicks 1, 2 and 10 Were Normal Chicks. Chicks 27, 35 and 34 Were Alco- 

 hol Chicks. The Fact That the Chick Jumped is Indicated by +. The 

 Fact That the Chick Refused to Jump is Indicated by — . 



Chicks Six Days Old 



Height 



No. of Chick 10.7 22.3 59.6 74 84.6 95 119.6 130 134 143 



1 + + + + + + + + — — 



2 + + + + + + + — 



10 + + + + + — 



27 + + + + + + + + - 



35 + + + + + + + + — 



34 + + + + - 



