The basement membrane of the otocyst on the 5-day-old chick embryo was positive to laminin. On the 9-day-old chick embryo, the basement membrane of the macula of the saccule and utricle was positive, but the crista ampullaris was positive very weakly. The basement membrane of the endolymphatic sac on the 11-day-old chick embryo was very strongly positive. These results suggest that laminin may be an essential substance for considering the pathology of the vestibular endorgans. The uneven distribution of laminin suggests that the basement membrane has some important function of the inner ear.
