In the following case the savage was right. I pointed out an object, dark, far off, so low down as to be just visible above the tall grasses, passing with a falling and rising motion like that of a horseman going at a swinging gallop. "There goes a mounted man," I remarked. "No--a traru," returned my companion, after one swift glance; the traru being a large, black, eagle-like bird of the plains. But the object was not necessarily more distinct to him than to me; he could not see wings and beak at that distance; but the traru was a familiar object, which he was accustomed to see at all distances--a figure in the landscape which he looked for and expected to find. It was only a dark blot on the horizon; but he knew the animal's habits and appearance, and that when seen far off, in its low down, dilatory rising and falling flight, it simulates the appearance of a horseman in full gallop. To know this and a few other things was his vocation. If one had set him to find a reversed little _s_ in the middle of a closely-printed page the tears would have run down his bronzed cheeks, and he would have abandoned the vain quest with aching eyeballs. Yet the proofreader can find the little _s_ in a few moments, without straining his sight. But it is infinitely more important to the savage than to us to see things quickly and guess their nature correctly. His daily food, the recovery of his lost animals and his personal safety depend on it; and it is not, therefore, strange that every blot of dark colour, every moving and motionless object on the horizon tells its story better to him than to a stranger; especially when we consider how small a variety of objects he is called on to see and judge of in the level monotonous region he inhabits.