Optic nerves in cyclopic and synophthalmic embryos of Gallus domesticus

The optic nerves of experimentally produced cyclopic and synophthalmic embryos of Gallus domesticus were studied to evaluate the course of the optic nerves in these abnormal circumstances. From this study it can be concluded that the course of the optic nerves appears largely to be a result of directional growth and that when decussation does occur in the optic chiasma, it results not from specificity as to side but from a tendency of outgrowing nerve processes to retain the direction of growth as fixed by axial orientation.