TRANSPLANTATION OF LIMBS IN AMBLYSTOMA 



143 



of the first spinal nerve is seen in cross-section. The distal 

 nerve trunk in the vicinity of the limb region is indicated by 

 the line a-a in figure 20. This nerve trunk represents a fusion 

 of the distal portions of the ventral rami of the first, second, 

 and third spinal nerves, all of which have grown considerable 

 distances anteriorh" to reach the transplanted limb. 



Two cases in which normal limbs developed, but which have 

 not been sectioned, are shown in figures 21 and 22. In case 



21 22 



Fig. 21 Dorsal view of case AA2S50, showing presence of normal fimctionless 

 limb, developed from rudiment transplanted into gill region (fig. 2). Animal 

 preserved forty-four days after the operation. X 5. 



Fig. 22 Dorsal view of case AA2S52, showing transplanted and regenerated 

 limbs. The base of the former is fused with a strip of gill ectoderm which has 

 grown out along its radial border. Incomplete reduplication of the hand is seen 

 in the regenerated appendage. Animal preserved forty-four days after the 

 operation. X 5. 



AA2S50 (fig. 21) the limb, although normal in appearance, was 

 practically devoid of function. One small gill developed which 

 was situated farther ventral than normal. In case AA2S52 

 (fig. 22) the transplanted limb was quite normal in appearance. 

 A fold of ectoderm extended out over its base and was fused 

 along the radial side, thus binding the limb close to the side of 

 the body. Just posterior to the transplanted limb there re- 

 generated another limb with reduplication of the hand. Gill 

 development was entirely suppressed. 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 35, NO. 2 



