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Mr. Graham Brown. 



when the contralateral stimulus is effective may yet not be accompanied by 

 restitution of extensor contraction. But that restitution may occur (figs. 1, 2). 

 It then is a slow movement and closely resembles the extensor contraction 

 in the "pure" contralateral reaction. Sometimes the flexor relaxation on 

 withdrawal of the interrupting ipsilateral stimulus is a slow one (figs. 1, 2). 

 Occasionally the flexor contraction may even be sustained after withdrawal 

 of the ipsilateral stimulus (fig. 3). In such cases the flexor contraction is 



Fig. 2. — Experiment M, XXTX, record 327, 8855 ; 1.6.13. — Macacus rhesus. From the 

 same experiment as fig. 1. This record was obtained 42 minutes after decerebration 

 and before the mesial longitudinal division of the mid -brain. 



The first reaction is here an ipsilateral one, and it is applied during the presence 

 of an extensor tonus from a preceding contralateral reaction. On stimulation 

 extensor relaxation and flexor contraction occur. The ipsilateral reaction is 

 followed by a good flexor after-discharge. 



The second reaction is a contralateral one. Here there occur flexor relaxation 

 and extensor contraction. The extensor contraction is again rhythmically notched. 

 The extensor after-discharge is not well marked. 



The third reaction is compound. The contralateral stimulus is first applied, and 

 is then interrupted by an ipsilateral. During double stimulation (g, g'-k, ti) there 

 is flexor contraction and extensor relaxation. The latter is not to so low a level, 

 and the former is not to so high a level as those in the " pure " ipsilateral reaction. 

 Withdrawal of the ipsilateral stimulus is followed by a slow flexor relaxation (it is 

 usually more rapid) and by extensor restitution of contraction. 



Compare this figure with fig. 1 (after mesial longitudinal division of the mid- 

 brain). Here the effects of compounding the two reactions synchronously and in. 

 temporal succession are demonstrated as they occurred before the lesion. 



