Development of the connective tissue of the extraocular muscles and clinical significance.

Mesectodern is an accurate term to describe the cellular origin of the connective tissue of the eye other than the eye muscles and vascular endothelium. The present study demonstrates that the tendons of origin and insertion, as well as the belly of the extraocular muscle, develops at the same time.

A reappraisal of the development of the eyelids.

The eyelids develop from ectoderm and from mesoderm. This evolution passes through distinct phases of maturation. Contemporaneously, the anterior segment of the eye takes form.

A re-evaluation of corneal development.

The corneal epithelium is initially a continuation of the surface ectoderm, but later on in development appears to arise from the superficial cells of the corneal stroma. The corneal epithelium varies in thickness depending on the status of the lids, viz either fused or open. When the lids are fused, the epithelium is only 2 to 3 layers in depth.

The origins and insertions of the extraocular muscles: development, histologic features, and clinical significance.

The tendinous origins and insertions of the extraocular muscles were studied embryologically by macroscopic and microscopic methods. It is concluded from this investigation that these tendons of origin and insertion arise from mesenchymal tissue similar to that of their respective muscles. These tendon-muscle groups have developed from superior and inferior mesenchymal complexes.