Many forms have become extinct, and, as we shall see when we come to speak of these bygone creatures, the lower we dig in the strata which compose the rocks of which our earth is made, the lower do the types become, that is to say, among the extinct Carnivora we have no animals so perfectly constructed for flesh-eating as the Cat family, for instance, but the various kinds get nearer and nearer, the lower we go, to what may be called the general plan of Mammalian structure, and farther and farther from the special type of structure found in the higher Carnivores of the present day. There is considerable range of size among the various members of the group, the Lion and Tiger being the largest, the Weasel and Suricate the smallest. As to their habits, the Carnivore are very varied; leaving out as we do for the present the fin-footed Seals, Sea Bears, and Walruses, we yet have the semi-aquatic Otter and the _Enhydra_, or Sea Otter, both at home in the watery element, and most expert swimmers and divers; but for the most part the flesh-eaters are inhabitants of the copse, the jungle, and the forest. Many are nimble climbers, some are arboreal in their habits, living entirely in trees, and most are crepuscular, that is, hunt their prey after dusk. As to their diet, we mentioned above that they are by no means all flesh-eaters; in fact there is every gradation from those which live exclusively on animal food, such as the Lion, Tiger, &c., to the purely herbivorous kinds of Bear. Some again, such as the Cat family, seem to prefer flesh-meat, others, such as the Otter, adopt a Lenten diet, and feed on fish or eggs. This matter, however, is, of course, largely determined by the habitat of the animal, those whose habitation is inland being compelled to devour land animals, while those living by the sea or by river-banks usually take to fish either occasionally or as a regular thing. Turning to the structure of the group, one of the first things that strikes us is the looseness of their skin, which, instead of being stretched on the body as tightly as a drum parchment, as it is in grass-eaters--for instance, the Ox or Hippopotamus--is quite “baggy,” having between it and the flesh of the beast a layer of the loosest possible fibres. It is for this reason that the skin of any but a _very_ fat Dog can be pinched up so readily, while of a Herbivore it may be said, in the words of eulogy uttered by Mr. Squeers of his son Wackford, “Here’s firmness, here’s solidness! why you can hardly get up enough of him between your fingers and thumb to pinch him anywheres.” In consequence of this the operation of skinning a Lion or Bear is a comparatively easy one. After the first cut the beast may be _pulled_ out of his skin, almost without further use of the knife; while with an Antelope or an Ox the skin has to be _cut_ away carefully and laboriously from the underlying flesh.