File:Streeter001.jpg

Fig. 1. Detail of a section through the lateral semicircular canal in a human fetus 33 mm long

(Carnegie Collection, No. 145, slide 7, row 1, section 3)

The section is 50 microns thick and is enlarged 370 diameters (original published image).

It shows the epithelial wall of the semicircular duct and the tissue zones that intervene between it and the cartilaginous capsule. In the outer part of the pre-cartilage zone is an intermediate area which is a transitional form between cartilage and precartilage. It is characterized by the scant amount of matrix and the incomplete and flattened condition of the capsule.

Reference

Streeter G.L. The histogenesis and growth of the otic capsule and its contained periotic tissue-spaces in the human embryo Contributions to Embryology Carnegie Institution No.20 (1918) pp5-54, 4 text-figures and 4 plates.