Ophthalmologists have been interested in the relation of growth and senescence of the human lens to ocular diseases because one course of pathologic events would occur in the eye if the lens were to grow continuously in size and another course would take place if the lens were to cease growing and become senile. The growth of the human lens from birth to death has been assumed to be continuous. The physiologic argument for the continuous enlargement of the lens which has been advanced by Priestly Smith1is that the lenticular cells "unlike those of the cuticle have no free surface and are not cast off as they grow" and that "they multiply within a closed capsule, and are laid down layer upon layer in such a way that the older are surrounded by the younger." If it is true, as Priestly Smith said, that the lenticular