Pathogenesis 459 



their normal metabolic function, as when their nerves are 

 severed, the fixation of the toxin and the occurrence of the 

 tonic spasm does not occur. 



Tetanus descendens results from the entrance of the toxin 

 into the circulation from the cellular tissue and its distribu- 

 tion in the blood. Under these conditions Zupnik believes 

 it acts upon the central nervous system, especially upon the 

 spinal cord, manifesting itself in extreme reflex excitability 

 with irregular motor discharges resulting in clonic spasms. 



There are, therefore, two forms of spasm in tetanus: 

 the tonic convulsions, seeming to depend upon local action 

 and fixation of the toxin, and the clonic convulsions, de- 

 pending upon the centric action. The latter are the more 

 dangerous for the sufferer. 



The lockjaw or trismus and the opisthotonos that are so 

 characteristic of the affection depend, according to Zupnik's 

 view, upon a loss of equilibrium among the muscles affected. 

 They occur only in descending tetanus and depend upon 

 spasm of muscles without equally powerful opposing groups. 

 The stronger muscles of the jaw are those that close it; the 

 stronger muscles of the back, those of the erector group. 

 This view is exactly the opposite of Meyer and Ransom,* 

 who believe that the tetanus toxin is absorbed only along 

 the nerve trunks, and found that section of the spinal cord 

 prevented the ascent of tetanus from the lower extremities. 

 Injection of the toxin into a posterior nerve-root produced 

 tetanus dolorosus. Injection of the toxin into a posterior 

 nerve-root together with section of the spinal cord produced 

 exaltation of the reflex irritability "Jactationstetanus." 

 Injection in sensory nerves does not produce tetanus doloro- 

 sus because the transportation of the poison along these 

 trunks is so slow. 



Pathogenesis. The work of Kitasato has given us very 

 complete knowledge of the biology of the tetanus bacillus 

 and completely established its specific nature. 



When a white mouse is inoculated with an almost in- 

 finitesimal amount of tetanus culture, or with garden earth 

 containing the tetanus bacillus, the first symptoms come 

 on in from one to two days, when the mouse develops 

 typical tetanic convulsions, first beginning in the neighbor - 



*"Archiv. f. experimentelle Path. u. Pharmak.," Bd. XLIX, 1903, 

 P- 396. 



