258 yoiiriial of Comparative Neurology and Psychology. 



red on seeing its precursors, which in itself seems good evidence of 

 ideation. Many times, however, they turned back after starting 

 at blue or white and looked for the red, then climbed up once more, 

 thus showing that the red was not a neglected element of the situ- 

 ation but an expected color which they generally waited to see, 

 but sometimes were too eager to wait for. Because of this fre- 

 quent turning back and waiting for red, I am certain that going up 

 to white and blue in the later trials was due to expectation of red 

 to follow. Not so in the earlier trials with No. 2 and No. 3. Their 

 numerous early errors at blue were due to the fact that they had 

 heretofore been trained with two colors, hence they went up most 

 frequently at the second. Although in the case of the two-color 

 training the colors were presented in varying order, the food color 

 must always appear next after the no-food signal so that the one, 

 two, relation was deeply fixed. Furthermore, at the beginning 

 of the two-color tests the "food" and "no-food" signals were given 

 alternately. No. i, on the other hand, had been previously trained 

 with three colors and now although blue, his former food signal, 

 was placed second as a no-food color, he made the mistake of 

 reacting to it only ten times in the first fifty because it was not 

 third, while he did go up to the final "no-food" red twenty-seven 

 times because it was third. It seems certain, therefore, that 

 raccoons are able to learn to distinguish one object or movement 

 from two and two from three, a species of counting not differing 

 from that which anthropologists ascribe to primitive man (see 

 Table XI). 



In the fourth group of fifty trials it will be noticed that No. i 

 failed to respond four times, while two is the maximum number of 

 preceding failures in any group of fifty. This occurred because in 

 this and succeeding groups I gave each series of colors twice The 

 previous alternate showing of each series caused hesitation and 

 failure to go up. I think his behavior also distinctly showed doubt. 

 In the same group of reds he stayed down 37 times, while in the 

 next group he stayed down only 28 times. May not the difference 

 of 9 trials be ascribed to his uncertainty ? It will be seen that this 

 change of orderincreasedhis mistakesin reactingto white, blue, and 

 the first two reds. All the mistakes accredited to first red after the 

 one hundred-fiftieth trial are reactions to the fourth red which, of 

 course, had to be recorded as occurring as the first red of a second 

 series. All this, I think, shows that introducing the new order, each 



