A review of data on cell actions and cell interaction during the morphogenesis of the embryonic eye

The early morphogenesis of the chick embryo seems to be an excellent model-system for study of morphogenetic movements, usually summarized in general terms like invagination, fusion and separation. This article reviews literature data about the early morphogenesis of the eye. The formation of lens vesicle and optic cup, during which invagination, fusion and separation are very important, were seen to represent a finely balanced interplay between cell mitosis, cell differentiation, cell death, cell transformation and cell migration. Differing observations and contradictory interpretations justify a systematic approach to to these embryological questions. We will attempt this in our next study. Apart from microscopic and submicroscopic description of closely succeeding developmental stages, three-dimensional reconstruction techniques will be indispensable to understand the spatial arrangement of the structures concerned.