STIMULI AND THEIR ACTIONS 475 



The principle of the specific energy of sense-substances in animals 

 provided with sense-organs, as discovered by Johannes Miiller, 1 has, 

 therefore, general application. All living substance possesses 

 specific energy in Miiller's sense; within certain limits wholly 

 different stimuli call forth in the same form of living substance 

 the same phenomena, while, conversely, the same stimulus in 

 different forms produces an effect wholly different and characteristic 

 for every form. 2 



1 Of. pp. 21 and 45. 2 Of. Hering ('84). 



