Scanning electron micrographs of digested clot surfaces. Different concentrations of plasmin were applied to the clot surface and samples were prepared for microscopy at various times. (A) 0.2 U/mL plasmin, 30 minutes. (B) 0.2 U/mL plasmin, 1 hour. (C) 0.2 U/mL plasmin, 3.5 hours. (D) Control, no plasmin. (E) 0.5 U/mL plasmin, 30 minutes. (F) 2.0 U/mL plasmin, 3.5 h. Bar equals 2 μm.