THE investigations recorded in the present paper have arisen out of the study of the local reactions of the cutaneous vessels by one of us (1) Finally we shall attempt to synthesise our results into a picture of the innervation.Methods. We have generally narcotised the frogs for the operations with urethane giving curari later when necessary. Operations, from which the animal is left to recover, require a number of precautions which were only gradually and, we fear, incompletely made out. Rana esculenta appears to stand the operations better than R. temp., but for