Abstract
On the 16th postoperative day the animals displayed discrete melanophoric dispersion. After extirpation of the ipsilateral 1st cervical sympathetic ganglion the toads underwent maximal darkening similar to that seen in toads with transection of the hypothalamic -hypophysial pathway. On the 45th day after transplantation, the eye containing the graft was enucleated and the melanophores immediately showed maximal concentration. These results are interpreted as additional evidence for maintaining that the adrenergic nerve fibers exert an inhibitory control on the secretion of melanocyte-stimulating hormone.