356 Miss S. C. M. Sowton. On the Reflex Effects in 



minute or two was necessary before repeating the stimulation, and the 

 latent period was very marked to be reckoned often in seconds. 



In experiments where the nerve roots were to be led off to the galva- 

 nometer, the frog was always curarised. A sciatic having then been 

 prepared as before for stimulation, its nerve roots (7th, 8th, and 9th 

 pairs), or the corresponding pairs of the opposite side, were exposed by 

 opening up the lower part of the spinal column ; the roots were then 

 carefully separated and those to be led off to the galvanometer were 

 cut as far as possible from the cord (just above the ganglion, in the 

 case of posterior roots). Two roots were usually taken together and 

 their central ends connected with the brush electrodes. 



In cases where the bulb was stimulated, the brain and upper half of 

 the cord were exposed, and the brain cut off at the bulb. The cord 

 having then been severed from its attachments, was carefully raised 

 and the bulb laid upon the stimulating electrodes. 



II. (1) Experiments showing Electrical Changes at the Central End 

 of Anterior Roots alone. Excitation of Sciatic of same side. 



Part stimulated. 



May 12. Coil 30 cm. 



June 21. Coil 15 and 

 10 cm. 



Central end of 

 left sciatic. 



Do. 



Part led off. 



Central end of 2 

 anterior roots of 

 same side. 



Central end of 1 

 anterior root of 

 same side. 



reflection of 

 galvanometer. 



10-40. 



510. 



II. (2) Ditto, ditto. Excitation of Bulb. 



June 25. Coil 10 cm. 

 June 29. Coil 10 cm. 



Part stimulated. 



Bulb. 

 Do. 



Part led off. 



anterior roots. 

 Do. 



