A very slight comparison of the face of this animal with that of any other will prove that strength is the object in view--strength toward the inferior part of the bone. In point of fact, the snout of the hog is his spade, with which, in his natural state, he digs and ruts in the ground for roots, earth-nuts, worms, etc. To render this implement more nearly perfect, an extra bone is added to the nasal bone, being connected with it by strong ligaments, cartilages, and muscles, and termed the snout-bone, or spade-bone, or ploughshare. By it and its cartilaginous attachment, the snout is rendered strong as well as flexible, and far more efficient than it otherwise could be; and the hog often continues to give both farmers and gardeners very unpleasant proofs of its efficiency, by ploughing up deep furrows in newly-sown fields, and grubbing up the soil in all directions in quest of living and dead food. As roots and fruits buried in the earth form the natural food of the hog, his face terminates in this strong, muscular snout, insensible at the extremity, and perfectly adapted for turning up the soil. There is a large plexus or fold of nerves proceeding down each side of the nose; and in these, doubtless, resides that peculiar power which enables the hog to select his food, though buried some inches below the surface of the ground. The olfactory nerve is likewise large, and occupies a middle rank between that of the herbivorous and carnivorous animals; it is comparatively larger than that of the ox; indeed, few animals--with the exception of the dog, none--are gifted with a more acute sense of smell than the hog. To it epicures are indebted for the truffles which form such a delicious sauce, for they are the actual finders. A pig is turned into a field, allowed to pursue his own course, and watched. He stops, and begins to grub up the earth; the man hurries up, drives him away, and secures the truffle, which is invariably growing under that spot; and the poor pig goes off to sniff out another, and another, only now and then being permitted, by way of encouragement, to reap the fruits of his research. FORMATION OF THE TEETH.