1. Differentiation of the posterior cells of the lens vesicle into lens cortex has been observed in vitro.
2. It is possible to dissect out the lens of the 5 day embryo chick in such a manner as to free it from all extraneous cells.
3. Lens epithelium even at a very early stage is contained within a cuticula.
4. Lens epithelium under proper conditions will live, migrate, divide, and multiply in vitro in primary explants.
5. An unmixed strain of lens epithelium can be propagated from a primary explant by successive subcultures. This strain can be utilized for controlled experiments on the nutrition of the cells of the lens.