MORBID ANATOMY 



307 



long continued discharge of pus must be severe. Mayo reports 

 several cases where the disease was watched for five or six 

 years and where it would possibly have continued several years 

 more had not the animals been destroyed. Most animals which 

 become affected with actinomycosis are either destroyed, treated 

 or slaughtered for beef in the early stages of the disease. 



§ 232. Morbid anatomy. The new actinomycotic 





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FiG. 74. A drawing' of an actinomycotic jaw. 



growths have in or near their centers rosettes of the ray fungus 

 surrounded usually by giant cells. These in turn are sur- 

 rounded by tissue consisting principally of epithelioid and 

 spindle shaped, connective tissue cells, among which giant 

 cells may appear. As these cells increase in number they 

 press against the surrounding tissues, thus producing the hard 

 and dense tumor-like growths. This is especially true when 

 they are located in the connective tissue. In certain other 

 positions, such as the liver, the inflammatory cells are sur- 

 rounded by a fibrous tissue framework which gives to the 

 lesion a honeycomb appearance. On section a disagreeable 

 "nutty" odor is given off which Mayo considers to be quite 

 characteristic of the di.sease. The outside of the tumor is 



