Pondering thus, I had been startled not a little by coming now and again on facts that seemed to bear this out. Strange tracks through untrodden grass suggested footsteps of the unseen. Flattened spaces of peculiar shape in the standing rye, where human beings could not have intruded, looked marvellously like human visitation. Or I lay concealed and watched the crows in a road-side field. What was it caused them to look up suddenly and flap away on sooty-fringed wings? No bird, beast, or man came. Then the rats, scampering about under a dock like so many gaunt Virginia swine: all at once came a flurry of whisking tails, and they were off! Yet I had not stirred, nor did anything move on the dock above. Nevertheless all seemed to realize a common danger, a noise of some kind,--perhaps a step? Again, you sit like a block while a snake basks unconscious in the sun, and may watch many hours without event; but sometimes it happens that he raises his head, quivers for an instant his double tongue, and slides off the stump into a bush. At such times put your ear to the earth. Do you not distinguish--or is it all imagination--a sound, a brushing? It availed me little, then, that I should have considered the subject, or have even gone the length of debating how a man might attain invisibility. Now that I had a tangible proof of the existence of such beings, I was crushed by misgivings. Like many a man before the supposed impossible, I questioned my own sanity. As to the impression, however, the object I had touched or fancied I had touched was at once hard and soft, smooth and rough; I recalled it as each of these in turn, for it was moving, and at the moment of contact bounded away as if at the shock of a galvanic current. To my excited mind the dusky woods were becoming oppressive, and so, like the hawk, but slowly and pondering, I betook myself home.