But you notice that the cow has a few different teeth in front; they are made to cut. Now watch a cow as she eats grass, and see how she uses these two kinds of teeth. With the front teeth she bites the grass—that is, she cuts it; then with the end of her tongue she puts it back where the grinding teeth are, to be ground before it goes into the stomach. So the cow has in her mouth both a cutting machine and a mill.
The horse has these two kinds of teeth, as you see represented in this figure, which is the skull of a horse.
The teeth of the horse, the cow, and the giraffe.
Now when you eat an apple you do very much as the cow or the horse does with the grass; with your front cutting teeth you bite off a piece; then it is pushed back where the grinders are, and they grind it up into a soft pulp before you swallow it.
The cow does not always use her cutting teeth in the way that I have mentioned. See her as she eats hay; she does not cut this as she does the grass. With those front cutting teeth she merely takes up the hay, and it is gradually drawn back into the mouth, the grinders all the while keeping at work on it. If the hay is in a rack, she pulls it out with her cutting teeth. It is the same with the horse.
That beautiful and singular animal, the giraffe, which you see here, has these two kinds of teeth. This animal, when of full size, is three times the height of a tall man; it lives on the leaves of trees, which it crops with its front teeth, grinding them up with its large back teeth, as the cow and horse do their hay and grass.
Tearing teeth.
You notice that your tearing teeth are not nearly as long and powerful as these teeth are in dogs, cats, tigers, etc. What is the reason of this? It is because, although you eat meat as they do, you can, with your knife and fork, cut up your food. They do not know enough to use such things, and so God has given them long, sharp teeth to tear their food to pieces.