The process of development of the crista ampullaris has been investigated in the mouse using SEM.
Cristae ampullaris of the CBA/CBA mice, from the 13.5th gestational day to the day 2 weeks by were studied.
On the 13.5th gestational day, there were numerous microvilli and a primary cilium on the crista ampullaris. Sensory hairs first appeared on the 14.5th gestational day. The kinocilium and stereocilia were short and the length of the stereocilia was almost constant. The formation of the cupula, which had fine networklike structures, started on the 14.5th gestational day.