POLYMYOSITIS AND MYOSITIS 159 



tained sarcous material, only represents the empty 

 sarcolemmar sheaths, with more or less remaining sarcous 

 debris and interpolated materials from the motor nerve 

 fibres, and, it may be, from the blood vasculature, through 

 inflammatory exudation and through the deprivation or 

 loss of lateral pressure on its component vessels, by the 

 withdrawal of the true sarcous matter from the affected 

 muscle fibres, and the consequent increase of local blood 

 pressure from passive hyperaemia. 



By continued pathological changes along these lines the 

 sarcous elements may disappear altogether, leaving only 

 more or less of the sclerosed sarcolemmar investments to 

 represent the original muscular structure, which may be 

 said to constitute the last stage of muscular atrophy or 

 myopathy, these latter affections following on, so to speak, 

 the asphyxiating influence of the inflammatory processes 

 and altered neuro-muscular metabolism. 



