86 BIOLOGICAL LECTURES. 



reacting differently to situations varying very slightly ; for 

 instance, running toward you when you hold up two fingers 

 and away from you when you hold up three. I may quote 

 what I have said elsewhere on this subject to give an idea of 

 the means of estimating this power in any animal. 



Delicacy of Associations. 



" It goes without saying that the possible delicacy of asso- 

 ciations is conditioned by the delicacy of sense powers. If an 

 animal does n't feel differently at seeing two objects, it cannot 

 associate one with one reaction, the other with another. An 

 equally obvious factor is attention ; what is not attended to will 

 not be associated. Beyond this there is no a priori reason why 

 an animal should not react differently to things varying only 

 by the most delicate difference, and I am inclined to think an 

 animal could ; that any two objects with a difference appreciable 

 by sensation which are also able to win attention may be re- 

 acted to differently. Experiments to show this are very tedious, 

 and the practical question is, ' What will the animal naturally tend 

 to do .-* ' The difficulty, as all trainers say, is to get the animal's 

 attention to your signal somehow. Then he will in time surely 

 react differently, if you give him the chance, to a figure 7 on 

 the blackboard from the way he does to a figure 8 ; to your 

 question, ' How many days are there in a week .-• ' and to your 

 question, ' How many legs have you .'' ' The chimpanzee in 

 London that handed out 3, 4, 5, 6, or 7 straws at command, 

 was not thereby proved of remarkable intelligence or of re- 

 markably delicate associative power. Any reputable animal 

 trainer would be ashamed to exhibit a horse who could not do 

 as much ' counting ' as that. The maximum of delicacy in 

 associating exhibited by any animal, to my knowledge, is dis- 

 played in the performance of the dog ' Dodgerfield,' exhibited 

 by a Mr. Davis, who brings from four cards, numbered i, 2, 3, 

 and 4, whichever one his master shall think of. That is, you 

 write out an arbitrary list, e.g., 4, 2, i, 3, 3, 2, 2, i, 4, 2, etc., 

 and hand it to Mr. Davis, who looks at the list, thinks of the 

 first number, says, 'Attention, Dodger !' and then, 'Bring it.' 



