372 TETANUS 



inoculation, and in this pus, besides other organisms, there was always 

 present, when tetanus had occurred, a bacillus having certain constant 

 microscopic characters. Inoculation of fresh animals with such pus 

 reproduced the disease. Nicolaier's attempts at its isolation by the 

 ordinary gelatin plate-culture method were, however, unsuccessful. He 

 succeeded in getting it to grow in liquid blood serum, but always in 

 mixture with other organisms. Infection of animals with such a culture 

 produced the disease. These results were confirmed by Rosenbach, who, 

 though failing to obtain a pure culture, cultivated the other organisms 

 present, and inoculated them, but with negative results. He further 

 pointed out, as characteristic of the bacillus, its development of terminal 

 spores. In 1889, Kitasato succeeded in isolating from the local suppura- 

 tion of mice inoculated from a human case, several bacilli, only one of 

 which, when injected in pure culture into animals, caused the disease, 

 and which was now named the b. tetani. This organism is the same as 

 that observed by Nicolaier and Rosenbach. Kitasato found that the 

 cause of earlier culture failures was the fact that it could only grow in the 

 absence of oxygen. The pathology of the disease was further elucidated 

 by Faber, who, having^ isolated bacterium-free poisons from cultures, 

 reproduced the symptoms of the disease. 



Bacillus Tetani. If in a case of tetanus naturally arising in 

 man, there be a definite wound with pus formation or necrotic 

 change, the bacillus tetani may be recognised in film preparations 

 from the pus, if the characteristic spore formation has occurred 

 (Fig. 124). If, however, the tetanus bacilli have not formed 

 spores, they appear as somewhat slender rods, without present- 

 ing any characteristic features. There is usually present in such 

 pus a great variety of other organisms cocci and bacilli. The 

 characters of the bacillus are, therefore, best studied in cultures. 

 It is then seen to be a slender organism, usually about 4 /z to 5 /A 

 in length and '4 //, in thickness, with somewhat rounded ends. 

 Besides occurring as short rods it also develops filamentous 

 forms, the latter being more common in fluid media. It stains 

 readily by any of the usual stains and also by Gram's method. 

 A feature in it is the uniformity with which the protoplasm stains. 

 It is very slightly motile, and its motility can be best studied in 

 an anaerobic hanging- drop preparation (p. 64). When stained 

 by the special methods already described, it is found to possess 

 numerous delicate flagella attached both at the sides and at the 

 ends (Fig. 125). These flagella, though they maybe of consider- 

 able length, are usually curled up close to the body of the bacillus. 

 The formation of flagella can be best studied in preparations 

 made from surface anaerobic cultures (p. 62). As is the case 

 with many other anaerobic flagellated bacteria the flagella, on 

 becoming detached, often become massed together in the form 

 of spirals of striking appearance (Fig. 126). At incubation 

 temperature b. tetani readily forms spores, and then presents a 



