The effect of neonatal treatment of male mice with antiandrogens and of females with androgens on the development of the os penis and os clitoridis.

The os penis in mice and rats is composed of a proximal intramembranous and endochondral osseous element and a distal cartilaginous, ossifying element. Female mice, but not rats, have a small os clitoridis which corresponds to the intramembranous part of the proximal element of the os penis. In mice of either sex a dense mesenchymatous formation ventral to the urethra is the anlage for the bones of the external genitalia.