On the Generation of Animals 788b10
"Democritus has spoken of these questions but not well, for he assigns the
cause too generally without investigating the facts in all cases. He says that
the early teeth are shed because they are formed in animals too early, for it
is when animals are practically in their prime that they grow according to
nature, and suckling is the cause he assigns for their being found too early.
Yet the pig also suckles but does not shed his teeth, and further, all the
saw-toothed animals suckle, but some of them do not shed any teeth except the
canines, e.g. lions. This mistake, then, was due to his speaking generally
without examining what happens in all cases; but this is what we ought to do,
for any one who makes any general statement must speak of all the particular
cases."