Equipotentiality of the Amphibian Eye Primordia

Abstract

THE experiments referred to below are concerned with the problem of the regulative power of embryonic anlage, the study of which has been taken to prove the equipotentiality of the eye primordia in amphibian embryos in the stages following the closure of the medullary folds. In Pleurodeles waltli it has been shown¹ that two optic vesicles may fuse together when that of the donor is transplanted in the close proximity of the optic vesicle of the host, keeping the same orientation of the normal position in the implanted eye. The degree of fusion depends upon the size of the removed portion of the vesicle in the host, and varies from that of double eyes partially fused to single eyes of larger size than the normal, which have developed by complete fusion of the two optic vesicles, which regulate its size afterwards, provided that the lens is not double.