A deaf and dumb lady living in a German city, had, as a companion, a younger woman, who was also deaf and dumb. They lived in a small set of rooms opening on the public corridor of the house. Somebody gave the elder lady a dog as a present. For some time, whenever anybody rang the bell at the door, the dog barked to call the attention of his mistress. The dog soon discovered, however, that neither the bell nor the barking made any impression on the women, and he took to the practice of merely pulling one of them by the dress with his teeth, in order to explain that some one was at the door. Gradually the dog ceased to bark altogether, and for more than seven years before his death he remained as mute as his two companions.