PROGRESS IN EXPERIMENTAL PSYCHOLOGY 



vestigations in allied fields. Nevertheless, a full decade 

 elapsed before another discovery of comparable impor- 

 tance was made. Then MarshaU'Hall, the most famous 

 of English physicians of his day, made his classical ob- 

 servations on the phenomena that henceforth were to be 

 known as reflex action. In 1832, while experimenting 



FRANCOIS MAGENDIE 



one day with a decapitated newt, he observed that the 

 headless creature's limbs would contract in direct re- 

 sponse to certain stimuli. Such a response could no 

 longer be secured if the spinal nerves supplying a part 

 were severed. Hence it was clear that responsive cen- 

 tres exist in the spinal cord capable of receiving a sen- 

 sory message, and of transmitting a motor impulse in 

 reply a function hitherto supposed to be reserved for 



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