116 FISTULA AND POLL-EVIL 



stubbornly attached, and carpeted here and 

 there with dormant granulations it prevents 

 cicatrization of the abscess cavity. It is this 

 stubborn viability of the ligamentum nuchse 

 that is responsible for the chronicity of poll- 

 evil. 



This stage, like that of fistula of the with- 

 ers, continues indefinitely, healing at one place 

 and bursting at another and all of the while 

 transforming the muscles into fibrous tissue. 

 The inflammatory process extends into the per- 

 iosteum of the atlas, into the capsule of the oc- 

 cipito-atlantoid articulation, into the meninges 

 and brain, into the neural canal and into the 

 spinal cord, producing the variety of comph- 

 cations for which poll-evil is known. 



An old poll-evil left to sojourn unmolested 

 or one indifferently treated usually exhibits 

 the following morbid states: a tumefied poll, 

 one or more apertures discharging pus, scars 

 of previous apertures, encrustations of dried 

 pus matted into the mane and surrounding 

 hairs, extended head from fibrous anchylosis 

 of the occipito-atlantoid articulation and a wab- 

 bly gait that becomes more and more accentu- 

 ated until the patient is unable to rise. Sec- 

 tioned, the poll is foimd to have been trans- 

 formed into a mass of hard, fibrous tissue, 

 which fuses all of the component structures in- 



