AFFECTIONS OF MUSCLES

The present study of muscle affections comprises two distinct patho-logical groups,-one neoplastic and the other inflammatory or myositic. Myositis is a comparatively common condition. It is a frequent sequel of injuries, mechanical irritation, muscle paralysis, and vascular disturbances. Pyogenic bacteria and toxins are common etiological factors. Syphilis, non-contiguous tuberculosis, and exanthematic dis-eases occasionally are responsible for muscle inflammation. Depending On the variety, the myositis may be acute or chronic, solitary or multiple, and it occasionally occurs in epidemic form (Richter and Levine, Massell and Solomon, and Morgan). In a total of 153 cases of muscle affections involving the extremities, body wall, and neck, recorded in the Surgical Pathological Laboratory, there were 108 cases of inflammation. Cases of chronic myositis made up the bulk of this inflammatory group. There were fifteen cases of tuber-culosis, eight of syphilis, six of trichinosis, and nineteen of chronic non