DEVELOPMENT OF THE OTIC CAPSULE: III. FETAL AND INFANTILE CHANGES IN THE FISSULAR REGION AND THEIR PROBABLE RELATIONSHIP TO THE FORMATION OF OTOSCLEROTIC FOCI

Abstract

The fissula ante fenestram, a channel of connective tissue extending from the vestibule at its junction with the scala vestibuli through the otic capsule in front of the oval window to the middle ear, is a constant structure in the human ear. It was first referred to by Huschke¹in 1844, by Hyrtl²in 1845 and by Siebenmann³in 1890. The early literature on this structure was summarized by me⁴in 1930 and need not be cited here. Since 1930 the fissula has been studied more extensively. In 1933 I⁵described its development from the earliest embryologic appearance to full term. Anson and Wilson⁶in 1933 described the fissula in an adult human ear, and Anson and Martin⁷in 1935 and Wilson⁸in 1935 discussed its form, contents, variations and deformations in early life. Considerable variations in the size and shape of