There are observations on record which compel the qualification of the assertion, I may have seemed to make in the preceding paragraph, of a clean break between man and animals. Certain dogs are thrown into paroxysms of fear by peals of thunder, and run into hiding. Darwin relates how his dog, 'full grown and very sensible,' growled fiercely and barked whenever an open parasol standing at some distance was moved by a slight breeze. He is of the opinion that the dog 'must have reasoned to himself, in a rapid and unconscious manner, that movement without any apparent cause indicated the presence of some strange living agent, and that no stranger had a right to be on his territory.'[13] Romanes, in a short and interesting paper entitled 'Fetichism in Animals,'[14] after reporting the preceding illustration, relates this observation touching a remarkably 'intelligent,' 'pugnacious,' and 'courageous' dog. 'The terrier [Skye] in question, like many other dogs, used to play with dry bones, by tossing them in the air, throwing them to a distance, and generally giving them the appearance of animation, in order to give himself the ideal pleasure of worrying them. On one occasion, therefore, I tied a long and fine thread to a dry bone, and gave him the latter to play with. After he had tossed it about for a short time, I took an opportunity, when it had fallen at a distance from him, and while he was following it up, of gently drawing it away from him by means of the long and invisible thread. Instantly his whole demeanour changed. The bone which he had previously pretended to be alive, now began to look as if it really were alive, and his astonishment knew no bounds. He first approached it with nervous caution as Mr. Spencer describes, but as the slow receding motion continued, and he became quite certain that the movement could not be accounted for by any residuum of the force which he had himself communicated, his astonishment developed into dread, and he ran to conceal himself under some articles of furniture, there to behold at a distance the uncanny spectacle of a dry bone coming to life.' Certain instances of instinctive fear of harmless things may help to interpret the preceding observations. G. Stanley Hall mentions a little girl who would scream when she saw feathers floating through the air. To keep another child in a room, it was sufficient to place a feather in the keyhole.[15]