In these animals, the incisors, such as are not damaged by use, are furnished, on the free border of their crown, with three tubercles, of which one, the median, is more developed than those which are situated laterally. We denote these teeth, commencing with those nearest the median line, by the names _central incisors_ or _nippers_, _intermediate_ and _corner incisors_. The canines, or _fangs_, are long and conical; they are curved backwards and outwards. The upper canines, which are larger than those of the lower jaw, are separated from the most external of the incisors (_corner_) by an interval in which the canines of the lower jaw are received. The lower canines, on the other hand, are in contact with the neighbouring incisors, and are each separated from the first molar which succeeds them by a wider interval than that which is situated between the corresponding teeth in the upper jaw. The molars differ essentially from the teeth of the same class in the human species. Their crown terminates in a cutting border bristling with sharp-pointed projections; this formation indicates that these teeth are principally designed for tearing. During the movement of raising the lower jaw, which is so energetic in the carnivora, they act, indeed, in the same manner as the two blades of a pair of scissors. The largest molars are: in the dog, the fourth of the upper jaw, and the fifth in the opposite one; in the cat, the third both above and below. The pig has forty-four teeth disposed in the following manner: 7_m._ 1_c._ 3_i._ | 3_i._ 1_c._ 7_m._ --------------------+-------------------- = 44. 7_m._ 1_c._ 3_i._ | 3_i._ 1_c._ 7_m._ Of the incisors, the nippers and the intermediate ones of the upper jaw have their analogues in those of the horse; in the lower jaw, the corresponding teeth, straight, and directed forward, rather resemble the same incisors in rodents. The corner incisor teeth are much smaller, and are separated from the neighbouring teeth. The canine teeth, also called _tusks_ or _tushes_, are greatly developed, especially in the male. The molars increase in size from the first to the last; they are not cutting, as in the carnivora, but they are not flattened and provided with tubercles on their surfaces of contact as in the herbivora. In the ox and the sheep the teeth are thirty-two in number: 6_m._ 0_c._ 0_i._ | 0_i._ 0_c._ 6_m._ --------------------+-------------------- = 32. 6_m._ 0_c._ 4_i._ | 4_i._ 0_c._ 6_m._ As we see from this dental formula, the incisors are found only in the lower jaw; they are replaced in the upper jaw by a thick cartilaginous pad on which the inferior incisors find a surface of resistance.