ELECTRON MICROSCOPY: MUSCLE: Muscle, skeletal, endomysium, fibroblast. (EM-labeled); RCH/AMC1608, soleus muscle, portions of four muscle fibers, one fiber shows a peripheral nucleus, endomysial fibroblast with an atypical nucleus, part of a capillary. 1-skeletal muscle fibers, 2-endomysial fibroblast, 3-capillary, 4-muscle