senses of smell, sight, and hearing, so necessary to animals of
prey. In short, the shape and structure of the teeth regulate the
forms of the condyle, of the shoulder-blade, and of the claws, in
the same manner as the equation of a curve regulates all its
other properties; and as in regard to any particular curve all
its properties may be ascertained by assuming each separate
property as the foundation of a particular equation, in the same
manner a claw, a shoulder-blade, a condyle, a leg or arm bone, or
any other bone separately considered, enables us to discover the
description of teeth to which they have belonged; and so also
reciprocally we may determine the forms of the other bones from
the teeth. Thus commencing our investigations by a careful
survey of any one bone by itself, a person who is sufficiently
master of the laws of organic structure may, as it were,
reconstruct the whole animal to which that bone belonged."[1]

We have already pointed out that no one is quite able to perform
the necromantic feat suggested in the last sentence; but the
exaggeration is pardonable in the enthusiast to whom the
principle meant so much and in whose hands it extended so far.

Of course this entire principle, in its broad outlines, is
something with which every student of anatomy had been familiar
from the time when anatomy was first studied, but the full
expression of the "law of co-ordination," as Cuvier called it,
had never been explicitly made before; and, notwithstanding its
seeming obviousness, the exposition which Cuvier made of it in
the introduction to his classical work on comparative anatomy,
which was published during the first decade of the nineteenth
century, ranks as a great discovery. It is one of those