calculated, when arrived at maturity, to subsist on various kinds of
food,--some to live wholly upon flesh, others upon grain, herbs, or
fruits; but in their infant state, milk is the appropriate food of the
whole. That this food may never fail them, it is universally ordained,
that the young should no sooner come into the world, than the milk
should flow in abundance into the members with which the mother is
supplied for the secretion of that nutritious fluid. By a wonderful
instinct of Nature, too, the young animal, almost as soon as it has come
into life, searches for the teat, and knows perfectly, at the first,
how, by the process of suction, it will be able to extract the fluid
necessary to its existence.