Fig. 1.

Re-evaluation of penile terminology to establish mouse human homology. (a) SEM of the adult mouse penis. The penile glans lies within an extensive preputial space beginning at the opening of the preputial space distally in the hair-bearing prepuce [a prominent elevation in the perineum labeled External prepuce in (b)] and ending proximally near the glans-body junction. Drawings of mouse (b) and human (c) morphology demonstrating the homology of the human prepuce and the mouse “internal prepuce” (both red) in so far as both are integral to the distal penis and encircle the glans.