Page:Natural History, Reptiles.djvu/272

by accident or disease, is very remarkably displayed by these animals.
SKELETON OF SALAMANDER. Numerous experiments, the cruelty of which we must again condemn, have been made on them by physiologists of eminence, especially by Bonnet, the results of which are very curious. "The arms and thighs of Trions amputated sometimes on one side, sometimes on the other, or both on the same side, were constantly reproduced, and the toes were gradually again formed and endowed with motion. The tail too, cut off at various points, was renewed, pushing out by little and little from the amputated base. In one case the same limb was reproduced four times consecutively in the same animal. Bonnet found that this reproduction was favoured by heat and retarded by cold. He observed that the parts of excised limbs were often reproduced with remarkable alterations, either of defect or excess; the deficiency or exuberance of certain parts taking upon themselves very singular forms. In many species of Tritons the long