Scanning electron micrographs of adult (60 day) mouse penises treated with oil vehicle and DES at the ages specified. (A-F) = end on views, (G-L) = lateral views, (M-R) = ventral views. Severe truncation of the MUMP (green arrowheads in I & J), malformation of the urethral meatus with abnormal clefting patterns in the MUMP ridge (C & D) and the ventral tether (purple arrowheads in I, J, O, & P) are seen in the P0-P10 and E12-P10 groups. Other treatment groups show less severe malformation or minimal departure from the oil treated specimens. IP = internal prepuce, MR = MUMP ridge, MRG = MUMP ridge groove, VC = ventral cleft in MUMP ridge.