TOXINS OF THE TETANUS BACILLUS 441 



Marie and Morax, they believe that absorption of toxin by 

 its bathing the lateral aspects of uninjured nervous structures 

 does not occur. In support of this they bring forward the 

 observation that when intravenous injection is practised, the 

 occurrence of tetanus in a part of the body can be precipitated 

 by the injection of a drop of normal saline into the correspond- 

 ing part of the cord, sufficient injury being thus caused to allow 

 the toxin in the surrounding lymph to obtain access to the 

 nervous elements. With regard to the action of tetanus toxin, 

 Meyer and Ransom believe that there is a double effect on the 

 nerve cells first, an exaggeration of the normal tonus, which 

 accounts for the continuous stiffness of the muscles and secondly, 

 an increase in reflex irritability, which is a prominent factor in 

 the recurring spasms. While no absorption of toxin takes place 

 by sensory filaments, they have found evidence of affection of the 

 sensory apparatus in the occurrence of what they call tetanus 

 dolorosus. This is a great hyperaesthesia and a paroxysmal 

 hyperalgesia which can be caused by injecting toxin into the 

 spinal cord or into a sensory root on the spinal side of the 

 posterior root ganglion. These symptoms are unaccompanied by 

 motor spasms, but the animal may die from exhaustion. The 

 same observers have also made interesting observations on the 

 action of antitoxin. They found that the injection of this sub- 

 stance into the course of a mixed nerve could prevent toxin 

 from passing up to the cord, but that if antitoxin were injected 

 even in great excess intravenously, and a short time thereafter 

 toxin were introduced into a nerve, the death of the animal was 

 not prevented. This they attribute to the fact that antitoxin 

 can only neutralise the toxin which is still circulating in the 

 blood. This is a very far-reaching conclusion, as it throws doubt 

 on what has been held to be a possibility, namely, that toxin 

 can be actually detached from cells in which it is already 

 anchored. But a still more significant observation was made, 

 for in one case of an animal actively immunised against tetanus, 

 and which contained in its serum a considerable quantity of 

 antitoxin, the injection of toxin into the sciatic nerve was 

 followed by tetanus. This would appear to militate against 

 Ehrlich's position that antitoxin is manufactured in the cells 

 which are sensitive to the toxin (see Immunity). 



Reference may here be made to the effects of injecting tetanus 

 toxin into the brain itself, as investigated by Roux and Borrel. 

 It was found that the ordinary type of the disease was not 

 produced, but what these observers called "cerebral tetanus." 

 This consisted of general unrest, symptoms of a psychic character 



