The sense of hearing is as perfect as that of sight; not, perhaps, in the higher, musical sense of the word, but for catching the faintest and feeblest undulations of the air. The Mole is supposed to be most sharp of hearing; but it is a question whether he is quicker of hearing than his cruel neighbour the Rabbit-killing Weasel. Any one who has watched a Cat sitting demurely by a Mouse-hole, or a Terrier on the look out for a Rat, will give these Carnivores credit for the most acute sense of sound. Anatomy corroborates what simple observation suggests, and the internal as well as external organs of hearing in the Carnivora are most exquisitely perfect. Many members of the group live in families, that is, a male and female with their young form a little _coterie_ by themselves, and associate very little with other families. Very few live in great societies or herds, after the manner of the grass-eating animals, such as Oxen, Antelopes, or Wild Horses, but an exception to this is afforded by the Wild Dogs of Constantinople, which roam the streets in great numbers, and by Wolves, which invariably hunt in packs. The Dogs and Wolves, besides being gregarious, resemble the Herbivora in another and far less amiable characteristic, that is, they do not choose a mate for life or even for a season, but let their affections run wild and practise the most unmitigated polygamy and polyandry. Many of the larger Cats, on the contrary--the Lion, for instance--choose a mate, to whom they are wonderfully faithful. The young are always born in a comparatively helpless condition, not able to run about at once like a new-born Calf or Foal; they are generally blind for some time after birth, and are entirely dependent on the mother for food and warmth. The higher Carnivora are most kind parents, and to the best of their ability, _educate_ their young. This was well known to the ancients: Ezekiel the prophet (xix. 2, 3) gives this character of the Lioness in inimitable language: “What is thy mother? A Lioness: she lay down among Lions, she nourished her whelps among young Lions. And she brought up one of her whelps: it became a young Lion, and it learned to catch the prey; it devoured men.” All writers bear witness to the painstaking way in which the parent Lion or Tiger trains up its young and practises them for their trade of slaughter. Sometimes both parents, sometimes only one, go out with their offspring, and by example and precept show them the safest places to hide, the proper moment to spring, the best place to seize the victim, and so on. And the future tyrants are very apt, they thoroughly enjoy their schooling, and make the best possible use of their opportunities; so much so that the young of the great Cats are far more dreaded than the old ones, as they not only kill to satisfy hunger, but commit wholesale slaughter, simply for practice and to keep their paws in.