EXPERIMENTS ON THE RABBIT 161 



was 30. The total percentage of correct choices made by Dark 

 Nose was 70: her percentage for the first three clays was 80, for 

 the second three days 75, and for the remaining two days 66. 



Series 9. Red and Hering grey number 24. Red opens. Con- 

 ditions and time as in Series 3. The total number of experiments 

 was 73. The total percentage of correct choices made by Dark 

 Nose was 64. Her percentages calculated every three days 

 were 66, 50, 75, 58, 66, 69. 



Series 10. Red and Stoelting black paper. Red opens. In 

 the experiments of this series Dark Nose was tested in the small 

 laboratory room, being picked up and dropped in front of the 

 middle of the experiment box, about three feet away from it. 

 Her four tests a day followed each other at a shorter interval 

 than before, when Light Nose was being tested in alternation 

 with her. The same considerations apply with regard to the 

 acquisition of an alternating habit as were noted under Series 4. 

 The total number of tests was 58. The total percentage of correct 

 choices made by Dark Nose was 31. Like Light Nose, she formed 

 the habit of going to the right-hand door, and we tried to break 

 up this habit by putting the red paper on the left-hand door a 

 number of times in succession. In all, 35 experiments were 

 made with the red on the left hand: in these she chose the red 

 only once. We made 23 tests with the red on the right hand, 

 and in these she chose the red 18 times. The formation of a . 

 place association by both Light Nose and Dark Nose when 

 this black paper was substituted for grey is the more noteworthy 

 since the external conditions were now somewhat different for 

 the two rabbits. The series had the same general time limits 

 as Series 4. 



Series 11. Red and Hering grey number 7. Red opens. The 

 conditions were as in Series 10. There were 61 tests in the 

 series. Dark Nose made a total of 80 per cent, of right choices. 

 In the first half of this series the right-hand tendency persisted : 

 all of the choices were correct when the red was on the right, but 

 only 36 per cent, were correct when the red was on the left. In 

 the second half of the series her record was without an error. 

 The series was made between February 21 and March 1. 



On March 1 a series of six tests was given in which Stoelting 

 black paper was substituted for red. The black was chosen 

 each time. 



