A study of the fine structure of the optic vesicle and lens placode of the chick embryo during induction

Abstract

1. 1. The observations, in general, confirm the morphological details of the chick optic vesicle and lens ectoderm during the time which induction of the lens is supposed to take place as described by McKeehan (1951). 2. 2. The fine structure of the optic vesicle and lens ectoderm is described. 3. 3. An interepithelial space, separating the optic anlage from the lens anlage, generally 1–3 μ in width, containing filaments, particles, basement membrane, and PAS-positive interepithelial clouds, is present in all stages investigated (stages 11 through 14, inclusive). 4. 4. There is a statistically significant change in the relative abundance of RNP particles between the optic vesicle and lens ectoderm, progressing from a greater abundance in the optic vesicle in stages 11 through 13 to a greater abundance in the lens ectoderm by stage 14. 5. 5. The findings are interpreted in the light of the suggestion of McKeehan (1956) that RNA may be transferred from optic vesicle to lens ectoderm during induction.