260 Mr. J. S. R. Russell. On the Nerve Moots of 



gradually become diverted, it may be through the anterior horn cells 

 of the spinal cord, along other channels. 



Part V (Control). Influence of Section of Root or Roots in excluding 

 part of an Epileptic Spasm induced in the Limb by Intravenous 

 Injection of Absinthe. 



In this series of experiments an attempt was made to obtain 

 further information as to the functional relations of the nerve roots 

 to the muscles they supply, by the following method of experimenta- 

 tion. A nerve root was first exposed, but not divided ; either a 

 jugular or femoral vein was exposed, and 2 minims of the essential 

 oil of absinthe injected into the vein by means of a hypodermic 

 syringe. In order to evoke subsequent epileptic attacks in the same 

 animal, doses of I minim of the oil of absinthe were found sufficient. 

 In some cases, after several injections of absinthe, the excitability of 

 the cortex became sufficiently increased to allow of general epilepsy 

 being evoked by means of the induced current applied to the 

 motor area of the cortex cerebri, a method which rarely succeeds 

 in evoking general epilepsy in the monkey under other circum- 

 stances. 



The first observation that was made in every instance was one to 

 determine the position assumed by the limb during the general con- 

 vulsions which followed the introduction of absinthe into a vein. In 

 this way it was easy to exclude any error due to injury of any of the 

 roots during the operation necessary to expose them. The position 

 which the limb assumed when all the nerve roots were intact was 

 one of flexion of thigh on the abdomen, with the leg at right angles 

 to the thigh at the knee joint, the foot dorsiflexed at the ankle, and 

 the digits flexed. 



When the 3rd lumbar root was excluded, the position assumed by 

 the limb was the same as on the opposite side on which all the roots 

 were intact, with the exception of the flexion of the thigh on the 

 abdomen being less pronounced. 



Exclusion of the 3rd and 4th lumbar roots allowed extension at 

 the hip to predominate over flexion, a result in keeping with the fact 

 that excitation of both these roots produced flexion at this joint; 

 while exclusion of the 5th lumbar root as well allowed flexion at the 

 knee to predominate more markedly over extension. After section of 

 the 6th lumbar on the same side, there was only feeble flexion at the 

 knee, with extension instead of dorsiflexion of the root and flexion of 

 the digits. The only intrinsic movement of the limb during general 

 convulsions when the 7th lumbar was also divided was adduction 

 and flexion of the hallux and flexion of the digits, movements which 

 we have seen resulted on excitation of the 1st sacral root ; and when 



