PATHOGENESIS 49 



viding there are no secondary cavities that do 

 not drain. 



During the fistulous stage of the disease we 

 must reckon, therefore, with a slowly dying 

 ligament, exfoliation of the ends of the spines, 

 the secondary pus due to the burrowing of pus 

 into adjacent spaces and the fibrosis that con- 

 tinues to encroach upon the surrounding mus- 

 culature. It is plain that these constitute a 

 combination of very inimical conditions. There 

 is also in addition to these, a chronic septicemia 

 that slowly but siu'ely undermines the general 

 health and manifestly reduces the patient's 

 vitality. The tracts leading from pus cavities 

 to the surface apertures, to still further com- 

 plicate matters, close up by cicatrization from 

 time to time and thus pen up the pus again until 

 it has burrowed out a new channel. During 

 this occurrence the patient is again sick as in 

 the phlegmonous stage, exhibiting pain, dis- 

 tress in movement, fever and general malaise. 

 Each attack of this kind leaves the patient more 

 enfeebled and still further damages the withers 

 by forming new tracts, more fibrous tissue and 

 sometimes new secondary cavities. The disease 

 ends in one of two ways: the common one is 

 emaciation and death, and the other is chronic 

 fistula, discharging limited amounts of pus for 

 several years. Rare cases heal up spontan- 



