CONTRIBUTIONS FROM PAWLOW'S LABORATORY 379 



an auditory stimulus. The conditioned salivary reflex to the stimulation with an 

 electric bell is from the start more intense than to the irritation with a faradic 

 current, and can completely replace the latter. A differentiation of the strength of 

 the electric current can not be accomplished, although the dogs form readily a 

 differentiation with regard to other stimuli. Dogs with a conditioned reflex 

 already worked out on the basis of electric irritation develop without any difficulty 

 or delay similar reflexes to other destructive factors (singing, squeezing, pricking) 

 whereby the defensive reflex never occurs. 



