Baculum morphology in the house mouse. (a) Line drawing of the main proximal bone of the baculum (dorsal view), indicating the three dimensions (maximum length, maximum base width, minimum shaft width) used in this study. (b) Line drawing of the same bone (shaded) in situ, illustrating the baculum’s position within the glans penis. Redrawn from .
Stockley et al. BMC Biology 2013 11:66 doi:10.1186/1741-7007-11-66