ORGANIC MOVEMENTS 57 



in its most primordial form, when Stentor, the experiment 

 with the powder being repeated after a short time, reacts 

 from the very beginning with its fourth kind of reaction 

 instead of with the first one. This example, besides its 

 excluding a whole group of motor phenomena from our 

 future discussion, may well serve at the same time to 

 illustrate provisionally what really will be called " action ' 

 by ourselves. 



The Distribution of Acting 



True actions, though, as will be stated later on, of a less 

 high degree of complication than actions in man, are most 

 clearly exhibited in the following classes of the animal 

 kingdom : in all, even in the lowest classes of vertebrates, 

 in bees, ants, and some beetles, in crabs, cuttle-fishes, 

 Actinia, and some Protozoa. 



One point has always to be kept well in mind in all 

 investigations about so-called animal "intelligence." All 

 organisms, of course, can acquire " experience " only about 

 what is " experienced " by them : in other terms, only 

 about that which stimulates them to motor reactions. Now 

 it is clear, that it always must remain doubtful in lower 

 organisms what sort of sense organs to use the common 

 expression at this stage of our argument they possess ; 

 their " medium " will only be the sum of the factors to 

 which they are accessible. How, for instance, could we 

 expect individualised stimuli to act upon organisms possess- 

 ing no organ like the eye or the ear ? Perhaps it is for 

 this one reason that so little is exactly known about real 

 acting in Protozoa. There are many observations about 



