102 M. I". WASHBURN AND EDWINA ABBOTT 



Series 12. Red and Hering grey number 15. Red opens. 

 This was the same combination as that used in the first experi- 

 ments with Dark Nose and Light Nose. The conditions were as 

 in Series 11. A total of 36 tests was made in the series, and Dark 

 Nose made but one error, a record of 97 per cent, correct. 



Series 13. Red and Hering grey number 15, with interpolated 

 red and velvet black tests. On March n and 12, after her pro- 

 longed and almost errorless record with red and grey number 1 5 , 

 we gave Dark Nose four tests in which for the grey there was 

 substituted the velvety black paper supplied with the Hering 

 color-mixing disks. We were much interested to see her choose 

 the black in all the four trials, wholly neglecting the red which she 

 had been choosing with machine -like regularity. Finding the 

 black door closed, she was allowed to get food from the red door. 

 On the next day four similar trials were given her. The records 

 for this day are in full as follows. 



" 1. Red on left. Sat still a long time, then went towards 

 red, but swerved and went to black. Box removed. 



' 2. Red on right. Sat still. Went straight to black, pushed 

 once and ran to red. 



"3. Red on left. Very eager to be picked up and put before 

 box. Sat still and seemed to look. Then went straight to red 

 and ate. 



"4. Red on right. Sat still a long time. Then went to red 

 door, with a turn of the head towards black, and got food." 



On the next five days we proceeded in the following manner. 

 We gave on each day four preliminary tests with red and grey 

 number 15. These were invariably correct choices, without any 

 hesitation on the rabbit's part. Then two tests were given with 

 red and velvet black, and then two final tests with red and grey. 

 These final tests were also always without error. In all there 

 were ten interpolated red and black tests. The results of these 

 may be given in detail from the records. 



" 1 . Red on left. Sat a long time, apparently looking intently, 

 with nose working. Finally started with a jerk, went to black, 

 barely touching it with a whisker. Box removed. 



"2. Red on right. Went casually to left side of box, by 

 black; touched black. Box removed. 



" 3. (Second day). Red on left. Hesitated; went to black. 

 Box removed. 



