106 THE ACUTE SELF-LIMITED INFECTIONS 



Between the time of introduction of the germs 

 and the outbreak of symptoms a period of incuba- 

 tion elapses which may be as short as three days or 

 as long as six weeks. The muscles nearest the wound 

 are affected first, as a rule, but the characteristic 

 symptoms of lockjaw soon appear. After death very 

 little is to be found by postmortem. 



The danger from patients with tetanus is quite 

 inconsiderable, the only infective material being the 

 discharges from the wound or the pieces cut away 

 surgically. Such objects are used for injection into 

 animals to establish a diagnosis. This, however, is 

 seldom necessary, as tetanus is quite clear in its symp- 

 tomatology. All dressings and pieces removed sur- 

 gically must be burned with actual fire. Boiling and 

 baking are unreliable. The first treatment usually 

 undertaken is the surgical cutting away of skin and 

 subcutaneous tissue far beyond the original wound, in 

 order to remove all bacilli. If these are removed no 

 more toxin can be made. 



The tetanus bacillus is large, TTSTTO to Woo" mcn 

 long by ^"oioT to "SWOT inch wide; it is a motile, spore- 

 bearing bacillus, growing only when the atmospheric 

 oxygen is shut out. The motility is due to flagella 

 arranged all about the cell wall. The spores develop 

 at one end and give the rod a drumstick appearance. 

 They are best seen in old cultures. The spores may 

 leave the parent bacillus and lead an independent 

 existence. In this state they are not motile, and are 

 stained with great difficulty. The vegetative rod, 

 however, stains with comparative ease. The organism 

 can digest gelatine and grows characteristically in it. 



