x MEMOIR. 
were conformable to what the teeth had announced, and the teeth to the 
feet; the bones of the legs and the thighs, and every thing that ought to 
reunite these two extreme parts were conformable to each other. In one 
word, each of the species sprung up from one of its elements. Those who 
will have the patience to follow me in these memoirs, may form some idea 
of the sensations which I experienced, in thus restoring by degrees these 
ancient monuments of mighty revolutions. This volume will afford much 
interest to naturalists, independent of geology, shewing them, by multi- 
plied examples, the strictness of the laws of co-existence, which elevate 
zoology to the rank of the rational sciences, and which, leading us to 
abandon the vain and arbitrary combinations that had been decorated with 
the name of systems, will conduct us at last to the only study worthy of 
our age—to that of the natural and necessary relations, which connect 
together the different parts of all organised bodies. But geology will lose 
nothing by this accessary application of the facts contained in this volume: 
and thus the numerous families of unknown beings, buried in the most 
frequented part of Europe, offer a vast field for meditation.” 
The reader will not fail to be struck with the expression of confidence 
which is uttered by Cuvier in the above passage, on the security which 
he felt in appealing to the immutable laws of nature, as the light which 
would enable him to trace the most beautiful of systems of harmony and 
order in this apparent chaotic mass of fragments; and he does not hesi- 
tate to enter further into detail on the nature of those immutable laws 
prescribed to living beings, to which he devoted the worship of his 
earliest and latest years. 
In the following passage Cuvier has more fully explained what he de- 
nominates ‘‘the immutable laws prescribed to living beings :’”—‘ Every 
organised being forms a whole and entire system, of which all the parts 
mutually correspond and co-operate, to produce the same definite action, 
by a reciprocal re-action; none of these parts can change, without a 
change of the others also. Thus, if the intestines of an animal are 
organised in a manner only to digest fresh flesh, it is necessary that his 
jaws should be constructed to devour the prey, his claws to seize and tear 
it, his teeth to divide the flesh, and the whole system of his organs of 
motion to follow and overtake it, and of his organs of sense to perceive 
it at a distance. It is necessary, also, that he should have seated in his 
brain the instinct to hide himself and spread snares for his victim: such 
are the general conditions of a carnivorous regimen; every carnivorous 
animal must infallibly unite them—without them the species could not 
subsist. But, under these general conditions, there are particular ones 
with respect to the size of the species, and the abode of the prey for 
which each animal is disposed.” 
