Differentiation of the facio-vestibulocochlear ganglionic complex in human embryos of developmental stages 13-15.

A study was made on 18 embryos of developmental stages 13-15 (5(th) week). Serial sections made in horizontal, frontal, and sagittal planes were stained with routine histological methods and some of them were treated with silver. In embryos of stage 13, the otic vesicle is at the rhombomere 5, and close to the vesicle is the facial-vestibulocochlear ganglionic complex in which the geniculate, vestibular, and cochlear ganglion may be discerned. These ganglia are well demarcated in embryos of stage 14. In the last investigated stage (15(th)) the nerve fibres of the ganglia reach the common afferent tract.