276 Mr. Graham Brown and Prof. C. S. Sherrington. [Mar. 16, 



Fig. 21. Fig. 22. 



Experiment 8, Macacus rhesus, 29.1.12. — Eecord of the stimulation of a cortical 

 flexion-point (E — F). The cessation of stimulation is seen here to be followed at an 

 interval of about 1*5 seconds by an extensor rebound contraction. 



Experiment 15, Callothrix, 5.3.12. — Eecord of the stimulation of an extension-point 

 (E — F). The cessation of stimulation is here followed at a short interval by extensor 

 relaxation and a small, but clear, flexor rebound contraction. 



IX. Conclusions. 



The cortical effects, as examined in this pair of antagonistic muscles, are 

 clearly very complex and composite. Variable latencies, sometimes of great 

 duration; long and varied after-actions, some tonus-like and others rhyth- 

 mically clonic, others in the nature of rebounds ; mutual relations of great 

 diversity between the reactions of the muscle-pair during actual stimulation ; 

 all these, along with other characters in the records not easily dealt with in 

 a short communication, impress upon the observer the high complexity of 

 the cortical as compared with decerebrate or purely spinal reactions. 



A phenomenon of outstanding prominence in the results has been that of 



