Of the investigators who have transplanted the adult eyeball, probably no one has insisted so strongly as Koppinyi that visual function had been restored. The present paper points out the inadequacy of certain of Koppbnyi's visual tests. It also presents experimental evidence making it doubtful whether vision may ever be restored in transplanted eyes of some of the forms which he employed.
Ask and Andersson ('27) carried out numerous reimplantations of the eyeball of the tench, Tinca vulgarus. In several eyes they obtained evidence that a few axis cylinders from the eye had penetrated the optic-nerve stump, although their photomicrographs show badly disturbed retinae in all cases. Ask states that Blatt obtained fourteen takes from 118 eye transplantations in fish. No signs of optic-nerve union or function were reported.
Many ocular transplantations have been carried out upon larval amphibians by Uhlenhuth, Krause, May and Detwiler, and others, but these were transfers of undeveloped eyes which merely complete their differentiation in a new location. Such transplants retain their embryological vigor, as does the 'The animals upon which testa are reported in this paper were kept at the Buesey Institution. The action-current tests Were carried out a t the Cruft Laboratory. I am indebted to t h e e laboratories for the facilities placed a t my disposal. I wish to express my gratitude to Miss Evelyn Suteliffe, of the Cruft Laboratory, whose experienced assistance in handling the action-current rpparatun has greatly supplemented my own efforts.