Studies on the process of lens induction inXenopus laevis (Daudin).

1. Optic vesicle from stage 24 (NIEUWKOOP andFABER 1956) can induce lens in the ectoderm from early to mid grastrula, and even from ventral ectoderm of a tail bud stage. 2. Lenses were induced from early ectoderm cultured over night before grafting even though it remained thick. 3. For lens formation and its differentiation, prolonged contact with the optic vesicle seems essential. 4. Lens anlage removed from the influence of the optic vesicle as late as the stage 24 (NIEUWKOOP andFABER 1956) and cultured as an explant attached to the head region failed to differentiate. 5. The environment offered by the head region and the headmesoderm plays an important role in determining the lens competence. 6. Xenopus optic vesicle can induce lens from Axolotl ectoderm. 7. There was no instance of retinal regeneration.