552 THE AMERICAN NATURALIST [Vol. LYI 



it were, the graft to the stock. During the last two years 

 my pupils and myself have tried to extend this method, 

 which I now call ' ' autophoric ' ' or self-retaining trans- 

 plantation, to other cases than the visceral sac of Ante- 

 don, and we have found that under these conditions func- 

 tion can be restored in a degree unknown till now, at 

 least in developed animals. 



The eye of vertebrates may be described as a ball- 

 shaped camera movable by three pairs of levers in all 

 directions of space, connected with its supply of chemi- 

 cals by the blood vessels and in communication with its 

 operator, the brain, by the optic nerve. If these fixing 

 strings are severed, there is scarcely any attachment to 

 the surroundings save some connecting tissue of unspe- 

 cialized sort. The " camera " itself will not be injured, 

 if the whole eyeball be taken out of the orbit, and there 

 is scarcely a possibility of altering the points of sever- 

 ance if the enucleation be made quickly and with decision. 

 If the eye is restored to its orbit, it will therefore be 

 possible for all the above-mentioned connections to join 

 again. This was observed as long ago as 1906 by Kug- 

 gero Pardo in Triton, who made experiments on the neces- 

 sity of the presence of the optic nerve for the regenerative 

 process in the eye of this amphibian. Unintentionally 

 he had excised the eyeball with the nerve and was much 

 astonished at its reattachment to the orbit. But will eye- 

 sight be restored with this reattachment? Pardo was not 

 able to convince himself of this fact, although on histo- 

 logical examination he found the optic nerve regenerated. 

 I have suspected for some time that the vertebrate eye 

 might furnish good material for the restoration of func- 

 tion by autophoric transplantation, as it will in many 

 forms be retained in the orbit by friction and atmos- 

 pheric pressure alone, aided also in some cases by the 

 eyelids closing over the eyeball, and by its great surface 

 securing wide contact with the blood issuing into the 

 orbit after extirpation. My own first experiments to 

 realize this expectation in new-born rats failed. 



