REGENERATED ANTERIOR LIMBS IN THE FROG. 



167 



the third or the second. In Fig. 3 this digit has suffered a re- 

 duction in its parts along with the fourth and fifth, and in its rela- 

 tively short length suggests the third digit, while the relatively 

 greater length of the corresponding digit in 2 suggests that it 

 may be the second. In both 2 and 3 the rudimentary pollyx is 

 present. In the carpal region there is but little differentiation in 



FIG. I. The skeleton of a regen- <f 

 crated hand. 



-' '" v \-. 



FIG. 2. A normal skeleton of an 

 ^x, anterior forearm and hand. The striped 

 are as are cartilaginous. 



the regenerated limbs, there being but little ossification in the 

 cartilage in 2, and no ossification whatever in the carpal region 



of 3- 



A striking feature in the regenerated limbs is the constant 

 appearance of the rudimentary pollyx. Sometimes this is repre- 

 sented by a separate cartilaginous structure as in Fig. 3, while in 

 other cases it is a mere projection from the fused cartilaginous 

 carpalia, as in Fig. 2. Even in hands that are greatly reduced 

 and distorted after regeneration, the cartilaginous projection of 

 the pollyx often persists, as in Fig. 4. 



