93 Prof. H. Meyer and Dr. F. Ransom. [May 7, 



The reflex answer to the attacks of pain consists in co-ordinated 

 defence movements, i.e., brain reflexes. 



We draw from these experiments the following conclusions : 



1. The tetanus toxine never reaches the spinal centres by way of the 

 sensory nerves. 



2. The pain apparatus in the spinal cord is so insulated from the 

 motor that an intoxication of the one group never goes over to the 



other. 



3. The actual movement of toxine in the nervous system takes place 

 not in the lymphatics but in the protoplasm of tJie nerves. 



In the third conclusion is to be found the explanation of the fact 

 that the cerebral tetanus of Roux and Bvrrd only occurs when the 

 toxine is injected into (or by some lesion can reach) the brain 

 substance. Between the brain and the peripheral nerves enough 

 ganglia are interposed to bar the access of toxine to the convulsion 

 centres. 



The occurrence of tetanus dolorosus and cerebral tetanus would 

 alone suffice to show that the toxine does not enter the nerve cells 

 from the blood-lymph stream. 



In the course of our researches on tetanus dolorosus we observed a 

 peculiar condition which set in after division of the spinal cord. So 

 soon as the communication with the brain was cut off, the manifes- 

 tations of pain ceased of course, but, instead, a state of things developed 

 which may be called jactation tetanus, the hind legs being kept almost 

 uninterruptedly in jerking movement for hours together, till finally 

 death occurred, apparently from extreme exhaustion. 



As long as the pain-impulse could reach the brain there was no sign 

 of this agitation, on the contrary, the animals kept as still as possible, 

 in order to avoid any irritation of the hypersesthetic area. But, trans- 

 mission to the brain being prevented, the energy set free by the pain- 

 stimulant discharged itself in the spinal cord, causing these movements.; 

 which may be looked upon as the spinal equivalent of the central reflex 

 movements of the intact animal. 



IV. Beliaviour of Tetanus Toxine towards Sensory and Vasomotor 



Nerves. 



Injection of toxine into the infra-orbital nerve did not give rise 

 to any symptoms analogous to tetanus dolorosus, but was once 

 followed, after the quite unusual incubation period of 14 days, by 

 an isolated tetanus of the erector muscles of the ear on the injected 

 side. 



Our observations lead us to think that the toxine may possibly be 

 carried centralwards in a sensory nerve, but that sensory disturbance 

 cannot be caused in this way. 



