358 TETANUS. 



can be practically no doubt as to their identity, as the 

 drumstick appearance which the terminal spore gives to the 

 bacillus is not common among other bacilli. Care must 

 be taken, however, to distinguish it from other thicker bacilli 

 with oval spores placed at a short distance from their 

 extremities, such forms being common in earth, etc., and also 

 met with in contaminated wounds (Fig. 87). It is important 

 to note that the wound through which infection has taken 

 place may be very small, in fact, may consist of a mere 

 abrasion. In some cases, especially in the tropics, it may 

 be merely the bite of an insect. The absence of a definite 

 channel of infection has given rise to the term "idiopathic" 

 tetanus. There is, however, practically no doubt that all 

 such cases are true cases of tetanus, and that in all of them 

 the cause is the B. tetani. The latter has also been found 

 in the bronchial mucous membrane in some cases of the 

 so-called rheumatic tetanus, the cause of which is usually 

 said to be cold. 



The pathological changes found post mortem are not 

 striking. There may be haemorrhages in the muscles which 

 have been the subject of the spasms. These are probably 

 due to mechanical causes. Naturally it is in the nervous 

 system that we look for the most important lesions. In the 

 spinal cord and medulla there is ordinarily a general redness 

 of the grey matter, and the most striking feature is the occur- 

 rence of irregular patches of congestion which are not 

 limited particularly to grey or white matter, or to any tract 

 of the latter. These patches are usually best marked in 

 the grey matter of the medulla and pons. There is general 

 slight congestion, and some tendency to the same appear- 

 ance of patches in the cerebrum and cerebellum, but to a 

 much less extent than lower down. Microscopically there 

 is little of a definite nature to be found. There is con- 

 gestion, and there may be minute haemorrhages in the areas 

 noted by the naked eye. The ganglion cells may show 

 appearances which have been regarded as degenerative in 

 nature, and similar changes have been described in the 

 white matter. The only marked feature is thus a vascular 



