THE 



AMERICAN NATURALIST 



VOL. XLII January, 1908 No. 4<J3 



HXPKKLMKXTS IN GRAFTING 



Tiiksk experiments were undertaken primarily to find 

 out whether it is possible by artificial means to induce 

 regeneration in a part that does not regenerate under 

 ordinary circumstances; and secondly to find out what 

 kind of a structure will regenerate from the proximal 

 end of so highly specialized an organ as the limb of a 

 salamander ; for, while we know that from the distal end 

 a new limb regenerates we have no information as to what 

 will happen if the proximal end is exposed. Since the 

 latter experiments gave more positive results they will be 

 first considered. As it is necessary to keep the IJnib alive 

 during the relatively long period required for its regen- 

 eration it was necessary to graft it, in a reversed position, 

 on to the same animal. 



The following method of grafting was employed. The 

 leg was cut off, the skin loosened around the attached 

 stump and turned back. The stump (composed of mus- 

 cles, bone, nerves, etc.) was cut off higher up and the skin 

 was then turned back. A pocket was thus formed. Into 

 tli is pocket the piece cut off was implanted, after being 

 turned around so that its proximal end was directed out- 

 wards. The skin was then drawn together by a ligature 

 over the cut end. Since it is desirable to draw the skin 

 completely over the exposed end without, however, press- 

 ing too much on the grafted piece, I have found it desir- 



