the following pertinent observations are reported : ( 1 ) the formation of stereocilia begins prior to the 15th day and continues to approximately the 18th day , ( 2 ) the formation of the stereocilia suggests a mechanism of gradual transformation of existing cell surface microvilli , ( 3 ) the onset of the genesis of stereocilia precedes neuronal contact and cuticular plate formation , ( 4 ) stereocilia rootlets are forming before cuticular plate formation , ( 5 ) utricular sensory hair cells have undergone significant ultrastructural differentiation prior to the development of synaptic contacts , and ( 6 ) nerve chalice formation of type 1 sensory cells begins on the 18th day and is still incomplete at birth .
C0026049
microvilli
C0007634
cells