SKIN TRANSPLANTATION IN FROG TADPOLES 



379 



tion. Tail-skin grafts were, therefore, placed over eyes whose 

 optic nerves had been cut, and also over empty sockets after the 

 removal of the eyes (the LO series, table 3) . In doing the former 

 operation a small piece of the optic nerve, about 1 mm. long was 

 removed, so as to prevent regeneration. 



The results of these grafts may be briefly stated. No absorp- 

 tion was seen in any of the LO grafts. The explanation is as 

 follows. After the severance of the optic nerve, the eye rapidly 



TABLE 3 

 The LO series 



Totals 



13 



10 tail 

 3 back 



7 op. n. cut 

 6 eye removed 



none 



degenerates. At the end of several weeks, postmortem examina- 

 tion showed onlj'^ the remains of the whitish opaque lens. The 

 operation and the degeneration of the eye which follows greatly 

 lessen and often obliterate the curvature of the conjunctiva, so 

 that grafts placed over such eyes are not under the same condi- 

 tions as grafts over normal eyes. Those over empty sockets are 

 either fiat or slightly concave on their outer surface. The absence 

 of curvature or the destruction of vision in the LO series may 

 have been the reason why absorption did not take place. All 



