1. Cross-sections of the anococcygeus at 30 days of age. The muscle area of
2. muscle of C57BL ICR and BALB/c mice neonatally DES-exposed female mice was
3. at 90 days of age showed histology charac- significantly larger than in controls and
4. teristic of smooth muscle. Sexual dimor- ovariectomy at 30 days of age did not alter
5. phism of the muscle was demonstrated in this indicating that the increase in the area