In a young larva ofRana esculenta, the budding fourth digit of a hind limb is cut off unilaterally. After 4 days, before regeneration has proceeded appreciably, the hind limbs are removed on both sides, fixed and compared with limbs of control larvae of identical stage. 2. It is found that one phalanx of the fourth digit is significantly shorter on the unoperated side than the corresponding phalanx of the controls. 3. The second and third digit, adjacent to the amputated fourth, lag behind in their growth compared with the controls.
