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T. H. MORGAN. 



developed. The condition of the carpus and tarsus appears to 

 be different in each of the four cases, Figs. 1-4. The rough re- 

 constructions shown in these figures were made from sections. 

 The figures are not very accurate, but serve to show the number 

 of bones and their relation to each other. The relative sizes of 

 the bones is less exact. It will be seen from the figures that the 

 regeneration has lead neither to the formation of a uniserial row 

 of skeletal elements, nor is it clear in all cases whether more 

 than a single toe is represented. It seems probable that the 



terminal middle phalanx represents a toe, but whether any of the 

 other cartilages represent other suppressed toes can not be stated. 



In these four cases the legs had been cut off through the 

 humerus, or the femur. It occurred to me that if the limb 

 were cut off through the fore-arm or the fore-leg the result 

 might possibly be different, since two bones are present at the 

 cut surface. Therefore on May 3, 1902, when the two regener- 

 ated legs were removed for study, the remaining two legs were 

 cut off through the fore-leg and fore-arm. 



The two amphiuma were kept alive for nearly another year ; 

 until March 30, 1903. They were occasionally fed on earth- 

 worms. The limbs that had been cut off through the fore-arm 

 and fore-leg regenerated, but again produced only a single 

 pointed, or in one case a somewhat flattened, new part. Serial 

 sections show that, besides completing the ends of the two bones 

 at the exposed surface, there have been produced a number of 

 more distal cartilages. The arrangement of these pieces is irregu- 

 lar, and different in each case, as also occurred when the leg was 



