DISEASES OP THE MUCOUS BUESA 241 



What forms of myositis are of practical interest to the sur- 

 geon 9 



1. Traumatic serous myositis. 

 3. Purulent myositis. 



3. Interstitial myositis. 



4. Ossifying myositis. 



6. Muscular rheumatism. 



TRAUMATIC SEROUS MYOSITIS. 



In what animal is it most frequently seen ? 



In the horse. 



What are its causes ? 



Contusions, as in runaways, railroad transportation,. OTer- 

 «xtension, contiguous inflammations. 



What course does traumatic myositis usually tahe ? 

 An' acute course ; more rarely a chronic one. 



What changes tahe place in a muscle in acute serous 

 myositis ? 



As the result of the inflammation a serous or hemorrha- 

 gic exudate invades the external and internal perimysium, to 

 he replaced by cellular infiltration, as in inflammation of 

 other organs. The muscle fibers are either left undisturbed 

 or undergo granular and fatty degeneration, which, of course, 

 "terminates their life period. In those cases followed by 

 resolution — that is, prompt recoyery — the contractile ele- 

 ments remain intact, while in those cases taking a chronic 

 •course the connective tissue of the perimysium proliferates 

 gradually, crowding the contractile substance out of ex- 

 istence. 



