APPENDIX 1.
Qualitative morphological features of adult mouse penis and clitoris
| Penis |
| Circular transverse profile |
| No tethering, freely moving organ |
| Urethra completely within the penis |
| Large os penis |
| Contains cartilage |
| Located in epithelium lined space |
| Surface (penile) spines |
| Large organ size |
| Clitoris |
| U-shaped epithelial lamina |
| Ventral tethering/immobile |
| Urethra never completely within clitoris |
| Miniscule os clitoris |
| No cartilage |
| Never located in epithelium lined space |
| No epithelial spines |
| Small organ size |