DISEASES. 719 



cartUage by a reddish, soft tissue, which also lines the inside of 

 the fistulous tract. This fistula, which extends from the necrosed 

 spot to the sldn, is but the hollow tract left by the diseased proc- 

 ess upon the cartilage, while gradually destroying its substance. 

 Always lined with a pseudo-mucous membrane, by a true pyro- 

 genic apparatus, the fistula is often narrow, sinuous, irregular in 

 its course and extent, especially if the disease is of some standing. 



Renault, and after him Lafosse, have mentioned a special al- 

 teration of the fibro-cartilage which is sometimes met, and which 

 Lafosse looks upon as a step toward recovery. It is a softening 

 of the tissue, anatomically characterized by a. loss of the consist- 

 ency of the cartUage, resembling the case of the cellular tissue 

 becoming indurated, or that of bones deprived of their earthly 

 salts after soaking in weak acids ; its yellowish color is then char- 

 acteristic. It may be noticed during Hfe, and is recognized by a 

 softening in the region of the cartUage, which then yields, giving 

 easUy to the pressure of the finger; besides thisj^a probe intro- 

 duced into the fistulous tract readily penetrates into the softened 

 substance. But the true way to diagnosticate this change con- 

 sists in raising the coronary band or after thinning the waU ; then 

 one wiU see and may feel the true nature of the transformation. 

 Lafosse adds that, in presence of this alteration, the removal of 

 the cartUage is no more necessary, for then the cicatrization is 

 readUy obtained by stimulating the sloughing of the necrosed tis- 

 sue or by removing it. 



With cartUaginous quittor there is always plastic infiltration 

 of the cellidar tissue surrounding the cartUage. Very often the 

 waU of the synovial capsule of the articulation of the foot is some- 

 what thickened, and in that case there is less risk of injuring it 

 during the operation. — (Key.) 



III. Progress, Duration and Termination. — Left to itself, 

 the caries of the fibro-cartUage may last for a long time, through 

 difficulty in determining its true nature. Spontaneous cure, how- 

 ever, is not impossible, as Eenault proved it, and as many practi- 

 tioners have seen it, especially in young and healthy subjects, 

 when the disease is mUd at its outset and effects parts of the or- 

 gans where the fibrous element predominates, as in the posterior 

 portion of the cartUage. This fortunate result foUows the slough- 

 ing of the "bourbillon" which makes its appearance under the 

 shape of a greenish particle. 



