200 Animal Intelligence 
black being in front (October 25-29). The reaction to the 
‘yes’ signal was perfect from the start. The progress with 
the ‘no’ signal is shown in Fig. 30, d. 
I then tried him with an apparatus externally of different 
size, shape and color from that so far used, showing as the 
‘yes’ signal a brown card and as the ‘no’ signal a white 
and gold card one half inch farther back in the apparatus. 
The ‘yes’ signal was practically perfect from the start. His 
progress with the ‘no’ signal is shown in Fig. 30, e. 
IT then tried a still different arrangement for exposure, to 
which, however, he did not give uniform attention. 
I then tried cards 1 and 101, 101 being in front and 1 in 
back. 1 was the ‘yes’ signal. ‘Yes’ responses were perfect 
from the start. For ‘no’ responses see Fig. 30, f. I then put 
the ‘yes’ signal in front and the ‘no’ signal behind. ‘Yes’ 
responses perfect ; for ‘no’ responses see Fig. 30, f, a. 
From now on I arranged the exposures in such a way that 
there was no difference between the ‘yes’ and ‘no’ signals 
in distance or surroundings. 
The following list shows the dates, signals used, and the 
figures on page 199 presenting the results. Where there is 
only one figure drawn, it refers to progress with the ‘no’ 
signal, the ‘yes’ signal being practically perfect from thestart. 
TABLE 10 
*Yxs’ SIGNAL ‘No’ Sicnar Ficure 
Nov. 13-15, goo. 2 102 g B 
Nov. 14-16, 1900. 3 103 a tt 
Nov. 16-19, Ig00. 4 104 h 
Nov. 19,  Ig00. 5 105 j 
Nov. 20, 1g00. 6 106 k 
Nov. 21, 1900. 7 107 1 
Nov. 23(?) 1900. 8 108 m 
Nov. 27-29, 1900. 9 109 n 
Nov. 30, 1900. Io IIo 0 
