ON THE TEETH OF MAMMALIA, 
135 
Hog (Sus Babirussa ), the canine teeth in the upper jaw are curved upwards so 
as to form a semicircle, and often a complete circle. In the common Wild Boar 
the tusks are often of immense size, and very powerful weapons of offence and 
defence. In the Bear there are two small canine teeth between the large ones 
and the molars, and which are also separated from these, latter by a considerable 
interval. Canine teeth are found in the Solidungula (Horse) under the appella¬ 
tion of tushes, which are also some distance from the molar teeth. Some have 
even affirmed that this space was left purposely to receive the bit. The Seals 
also possess canine teeth, and all their molars partake considerably of the same 
nature, being pointed and sharp. In the Ruminaniia we find the camel supplied 
with these teeth. The Musk ( Mosckits moschiferus) has a long canine tooth on 
each side of the upper jaw, projecting in the male considerably beyond the lips. 
The Bat family is provided with four large canine teeth. These teeth in the 
Mole have two roots like false molars. 
III. Molares , Back, Molar, or Grinding Teeth.—These teeth are found in all 
Mammalia that have any teeth; their form is very various, and adapted to the 
food and manners of the animal. Thus we see the crown of the molar teeth in 
Carnivorous animals sharp and angular. In the Graminivorous animals, on the 
contrary, the crowns are broad and flat, and more or less grooved, as their food 
requires to be much bruised preparatory to digestion. In Omnivorous animals 
(as Man) these teeth are elevated and more or less angular at the edges, and 
depressed in the centre. In all classes they are fully adequate to perform the 
part allotted to them in the function of digestion. The Armadilloes, and the 
Cape Ant-eater, have molars, but are destitute of incisores or canine teeth. 
The Narwhale is the only exception to the rule laid down above, as it has merely 
its tusks, which are inserted into the intermaxillary bone, and are therefore 
incisors. In Man and the Quadrumana or Monkies, the two front molars are 
smaller in the crowns, and more simple in the roots than the more posterior ones. 
In these as well as the Carnivora (Lion, Tiger, Dog, &c.), and some Rodentia (as 
the Marmot) the crown is covered with enamel. In the Horse, Sheep, Cow, 
Elephant, &c., bony substance is seen on the upper surface of the tooth, running 
in lines of different forms in each order. In all these animals the enamel runs 
down into the body of the tooth to a considerable depth. In Graminivorous 
animals that do not ruminate (as the Horse, Elephant, &c.) the crowns of the 
molar teeth lie nearly in an horizontal direction with respect to each other. In 
most of the Ruminants the surface of these teeth is oblique, the outer margin of 
the upper, and the inner one of the lower tooth being most prominent. In the 
Carnivora (as the Dog, Lion) the crowns of the molar teeth are uneven, and end 
in pointed processes with depressions between them; these lock into the cor- 
