Photomicrographs of longitudinal sections of femur in mice after 7-day administration of either G-CSF (A, B, and C) or saline (D, E, and F). Mice were killed on day 14 of treatment, and the histologic sections of the trabecular region of the metaphysis (A and D at original magnification × 100, B and E at original magnification × 400) and endosteum of bone shaft (C and F at original magnification × 400) were stained for tartrate-resistant acid phosphatase.