44 Animal Intelligence 
tions are easy for an animal to form, and what are hard. 
! The act must be one which the animal will perform in the 
\course of the activity which its inherited equipment incites 
jor its previous experience has connected with the sense- 
impression of a box’s interior. (The oftener the act nat- 
: od 
einE. 14 GinE 14 14 ) 
Fic. 5. 
urally occurs in the course of such activity, the sooner it 
will be performed in the first trial or- sd) and this is one con- 
dition, sometimes, of the ease of forming the association, 
For if the first few successes are five minutes apart, the 
influence of one may nearly wear off before the next, while 
if they are forty seconds apart the influences may get sum- 
mated. But this is not the only or the main condition of 
the celerity with which an association may be-formed. It 
depends also on th¢’amount of attention given to the act; 
“An act of the sort likely to be well attended to will be learned. 
