Abstract
The first observations on the development of the optic nerve layer (ONL) of chick retina were made near the end of last century, but it was not until recently that an electron microscopic study of this region showed that myelinated fibres were present and that this myelin differed in structure from myelin elsewhere. Studies on the histochemistry and ultrastructure of chick retinal myelin are few. There are no reports dealing with ultrastructural details of myelin development in the chick retina. In this study such observations were undertaken with the transmission electron microscope.