1906.] 



0)i Innervation of Antagonistic Muscles. 



489 



Fig. 6. — Crossed extension-reflex. The reflex was being elicited regularly by short series 

 of break-shocks, the series being equal in intensity and duration. (In 26 nine shocks 

 were delivered instead of eight in the other stimulations, owing to a defect in the 

 rotating key.) Reflex No. 1 is the last of a series of equal reflexes thus provoked ; 

 both stimulus and reflex were of low intensity. After reflex No. 1 in the one-minute 

 interval between it and 2a, a strong flexion-reflex of the limb was excited and main- 

 tained for 40 seconds. The next following reflex 2a exhibits augmentation, and this 

 augmentation is obvious also in reflex 26. Reflex 2o" was elicited two minutes after 

 26, and shows no augmentation. It is somewhat less than the reflex evoked just prior 

 to the intercalated flexion-reflex. The signal above registers the time, etc., of the 

 break-shocks used as stimuli. Time is marked below in seconds. The intensity of 

 the stimulus and the place of its application remained unaltered throughout the 

 series of observations. 



2 n 2 



