[Contralateral effects of limb removal in the chick embryo]

The bud of the right posterior limb was removed from 4 to 6 days old chick embryos, followed by removal of the muscles of the left posterior limb, with the sciatic nerve and the lumbosacral spinal marrow on the 17th day. ChAc and AChE activities were measured on the amputation side (spinal marrow), on the contralateral side (spinal marrow, nerve and muscles), and in control embryos. There was a significant fall in both activities on the contralateral side, particularly when amputation had taken place on the 4th day. It was also noted that the myelinic fibres of the anterior root on the contralateral side were more numerous than in the control embryos, and that the muscle fibres had a different appearance.