color schemes as the bright red of the marsh-deer, the black of the black jaguar, and the black with white stripes of the great tamanduá, are not positive detriments to the wearers. Yet such is evidently not the case. Evidently the other factors in species-survival are of such overwhelming importance that the coloration becomes negligible from this standpoint, whether it be concealing or revealing. The cats mould themselves to the ground as they crouch or crawl. They take advantage of the tiniest scrap of cover. They move with extraordinary stealth and patience. The other animals which try to sneak off in such manner as to escape observation approach more or less closely to the ideal which the cats most nearly realize. Wariness, sharp senses, the habit of being rigidly motionless when there is the least suspicion of danger, and ability to take advantage of cover, all count. On the bare, open, treeless plain, whether marsh, meadow, or upland, anything above the level of the grass is seen at once. A marsh-deer out in the open makes no effort to avoid observation; its concern is purely to see its foes in time to leave a dangerous neighborhood. The deer of the neighboring forest skulk and hide and lie still in dense cover to avoid being seen. The white-lipped peccaries make no effort to escape observation by being either noiseless or motionless; they trust for defence to their gregariousness and truculence. The collared peccary also trusts to its truculence, but seeks refuge in a hole where it can face any opponent with its formidable biting apparatus. As for the giant tamanduá, in spite of its fighting prowess I am wholly unable to understand how such a slow and clumsy beast has been
