Of the Teeth.
Why do they only, amongst all other bones, feel the sense of feeling?
Because, as Avicen and Galen do say, they might discern of heat and cold which hurt them, which other bones need not.
Why have men more teeth then women?
By reason of the abundance of heat and blood which is more in men than in women.
Why do the teeth grow to the end of our life, and not the other bones?
Because otherwise they would be consumed with chewing and grinding.
Why do the teeth only come again when they fall, or be taken out, and other bones taken away grow no more?
Because that, according to Aristotle, all other bones are engendered of the humidity which is called radical, and so they breed in the womb of the mother, but the teeth are engendered of nutritive humidity, which is renewed and increased from day to day.
Why do the fore teeth fall in youth, and grow again, and not the cheek-teeth?
This proceedeth of the defect of matter, and of the figure, because the fore-teeth are sharp, and the others broad. But, according to Aristotle, there is another answer: that is, that it is the office of the fore-teeth to cut the meat, and therefore they are sharp; and the office of the other to chew the meat, and therefore they are broad in fashion, which is fittest for that purpose.
Why do the fore-teeth grow the soonest?
Because we want them sooner in cutting than the othrr in chewing.
Why do teeth grow black in the old age of human creatures?
This proceedeth of the corruption of the meat, and the corruption of phlegm, with a naughty choleric humour.
Why are colts' teeth yellow, and of the colour of saffron when they are young, and wax white when they be old?
Aristotle saith, that a horse hath abundance of watery humours in him, which in his youth are digested and converted into grossness; but in old age heat is diminished, and the watery humours remain, whose proper colour is white.
Why did nature give living creatures teeth?
Aristotle saith (lib. de generat animal), to some to fight with, and for defence of their lives, as unto wolves and bats; unto some to eat with, as unto horses; unto some for the forming of their voice, as unto men, "as it appeareth by the commentary in the book de animal."
Why do horned beasts want their upper cheek teeth?
According to Aristotle in his book de animal horns and teeth are caused of the self-same matter, that is of nutrimental humidity, and therefore the matter which passeth into horns turneth not into teeth, consequently want the upper teeth. And such beasts, according unto Aristotle, cannot chew well; whereupon for want of teeth they have two stomachs by consequence, and so do chew their meat twice; and they do first convey their meat into the first stomach or belly, and then return it from whence it came, and chew it.
Why are some creatures brought forth with teeth as kids sad lambs, or some without, as men?
Nature doth not want in things necessary, and abound in things superfluous; and therefore, because these beasts not long after they are fallen do need teeth, are fallen with teeth: but men are nourished with their mother's dugs for a time, and therefore for a time do not want teeth.
Why have not birds teeth?
Because the matter of teeth passeth into their beak, and therefore there is their digestion; or else it is answered that although they do not chew with teeth, yet their head in digestion doth supply the want of teeth.