I 92 BACTERIA 



from opisthotonos. The seizures may be constant or tonic; or con- 

 vulsive and violent, then they are designated as clonic. 



Immunity. Metchnikoff claims that the only natural immu- 

 nity possessed by man against tetanus resides in his leucocytic 

 powers of defense. Susceptibility of the natural receptors of the 

 nerve cells for the toxin, and the degree of affinity, constitutes the 

 cause of intoxication, its degree, and ultimate result. Affinity for 

 the receptors of other less vital organs, on the part of the toxin, 

 establishes a means of natural defense. Acquired immunity is 

 dependent upon the formation of anti-toxin. The anti-toxin, 

 formed by susceptible animals injected with tetanus toxin, is 

 chiefly useful and valuable as a prophylactic measure. An epi- 

 demic of puerperal tetanus in a lying-in hospital was checked by 

 its use. Sprinkling dry powdered anti-toxic serum on wounds in- 

 fected with tetanus bacilli, or toxin, prevented infection (Calmette 

 and McFarland). The anti- toxin may be injected either into the 

 substance of the brain in cases of well developed tetanus, or into 

 the cerebrospinal fluid, in the hope of neutralizing the toxin not 

 already in firm combination with the nervous elements. Large 

 nerves near the infecting wound may be injected with anti-toxin 

 in the hope of binding the toxin already in combination with the 

 nerve cells (see page 74) . 



Female mice immunized against tetanus toxin, transmit a great 

 amount of immunity to their offspring. The milk of an immun- 

 ized mouse also causes a passive immunity in other young that are 

 suckled by her. 



BACILLUS OF MALIGNANT (EDEMA 



Bacillus (Edematis Maligni. . 



Vibrion septique. 

 Bacillus of Malignant (Edema. 



Morphology and Stains. Thickish rods, resembling tetanus 

 and symptomatic anthrax bacilli, with a tendency to grow in long 



