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will more fully determine the structure of the bones. It
may be seen that we could draw equally just
conclusions for the hinder quarters, which contribute
to the rapidity of the general movements; as to the
formation of the body, the shape of the vertebræ,
which influence the ease and flexibility of the motions;
as to the form of nasal bones, of the socket of the eye,
of the ear, whose mutual relation to the perfection of
the sense of smelling, seeing, and hearing, are so
palpable. In a word, the formation of the tooth
bespeaks the structure of the articulation of the jaw,
that of the scapula, that of the claws, just as the
equation of a curve involves all its properties; and in
taking each property separately, as the basis of a
particular equation, we shall find again both the
ordinary equation and all the other certain properties:
so the claw, the scapula, the articulation of the jaw,
the thigh bone, and all the other bones separately
considered, require thecertain tooth, or the tooth
requires them reciprocally; and beginning with any
one, he who possessed a knowledge of the laws of
organic economy, would detect the whole animal.
This principle is sufficiently self-evident, in the
usual acceptation, not to require a farther
demonstration; but when we come to apply it, there are
many cases in which our theoretic knowledge of the
mutual relations of the structure would not be
sufficient, if it were not supported by observation.
We see, for instance, very plainly, that hoofed
animals must all be herbivorous, since they have no
means of seizing upon their prey; we see also that,
having no other use for their fore-feet than to support
their bodies, they have no occasion for so powerfully-
framed a shoulder; whence we may account for the
absence of the clavicle and the acromion,

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and the straightness of the scapula; not having any
occasion to turn the fore-leg, their radius will be
solidly united to the cubitus, or at least articulated by
a hinge-joint, and not by ball and socket, with the
shoulder; their herbaceous diet will require teeth with
a broad surface, to crush seeds and herbs; this breadth
must be irregular, and for this reason, the enamelled
parts must alternate with the osseous parts; this sort of
surface compelling horizontal motion, for grinding the
food to pieces, the articulation of the jaw cannot form
a hinge so close as in carnivorous animals; it must be
flattened, and cor respond with the facing of the
temporal bones, more or less flattened; the temporal
cavity, which will only contain a very small muscle,
will be small and shallow, &c. All these things are
necessary deductions one from another, according to
their greater or lesser universality; and so that some
are essential and exclusively belonging to hoofed
animals, and others, although equally necessary to
those animals, are not peculiar to them, but are to be
found in other animals, where the other general rules
of structure admit of these also.
If we descend to the orders or subdivisions of the
class of hoofed animals, and examine what
modifications the general condition undergo, or rather
what peculiar conditions are united to them, according
to the character proper to each of these orders, the
reasons of these secondary conditions begin to appear
less palpable. We soon perceive, in general terms, the
necessity of a digestive system more complicated in the
species where the dental system is more imperfect; thus
we might say that these should rather be ruminating
animals, where such and such an order of the teeth is
wanting; we may deduce from it a certain form of the
œsophagus,

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and corresponding formation of the vertebrae, of the
teeth, &c. But I doubt whether any one would have
guessed, if observation had not suggested it, that
ruminating animals would all have cloven feet, and
that they alone would have them: I doubt whether any
one would have guessed that those only would have
horns on the forehead that belong to this class; that
those amongst them who have sharp eye-teeth are for
the greatest part deficient in horns, &c.
However, since these coincidences are constant, they
must have a satisfactory cause; but as we do not know
it, we ought to supply the defect of the theory by
observation; it serves us to establish suppositious laws,
which become almost as certain as the laws of
reasoning, when they rest on often-repeated
observations; so that now, any one who sees the track
of a cleft foot may conclude that the animal who left it
is ruminant; and this assertion is as sure as any other
in physics or morality. This footmark alone gives to
the observer both the formation of the teeth, the shape
of the jaws, the structure of the vertebræ, and the form
of all bones of the legs, thighs, shoulders, and even the
frame of the animal which has passed. It is a more
certain mark than all those of Zadig.
Whatever secret reasonings there may be in these
relations, it is observation which has elicited them,
independently of general philosophy.
In fact, when we make an assemblage of these facts,
we remark not only a specific consistency, if we may
use such a term, between a certain formation of a
certain organ, and a certain formation of a different
organ; but we perceive also a classified consistency,
and a correspondent gradation in the development of
these two organs, which evince,

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almost as well as an effective reasoning, their mutual
influence.
For example, the dental system of hoofed animals,
not ruminant, is usually more perfect than that of
cleft-footed animals, or those which ruminate, because
the former have either incisores or canine teeth, and
generally both in both jaws;. and the structure of their
foot is more complicated, be cause they have more
toes, or nails which less enclose the phalanges, or more
separate bones of the metacarpus and metatarsus, or the
bones of the tarsus more numerous, or a more distinct
prominence of the tibia, or in fact because they unite
all these points. It is impossible to account for these
correspondences; but what proves that they are not the
effect of chance, is, that whenever a cleft-footed
animal shows, in the arrangement of its teeth, any
tendency to a similarity with the animals of which
weare speaking, it also evinces a similar tendency in
the formation of its feet. Thus camels, which have
canine teeth, and even two or four incisors in the
upper jaw, have a bone more in the tarsus, because
their scaphoid is not. united with the cuboid, and very
small nails corresponding with the phalanges which
have nails. The chevrotains, whose canine teeth are
much developed, bear a distinct mark along the tibia,
whilst other cleft-footed animals have only, instead of
the fibula, articulated a small bone along the tibia.
There is then a constant harmony be tween two organs
apparently very distinct from each other; and the
gradations of their formation correspond without
alteraticin, even in cases where we can assign no cause
for the similarity.
But, in thus adopting the method of observation as
an additional means when theory forsakes us, we arrive
at astonishing results. The least prominence

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of the bone, the smallest apophysis, have a determined
character, relative to the class, the order, the genus,
and even the species to which they belong; so that
whenever we have only the extremity of a well-
preserved bone, we may, by scrutinizing it, and
applying analogical skill and close comparison,
determine all these things as certainly as if we had the
whole animal. I have often in this way experimented
on portions of known animals, before I entirely
applied the test to fossils; but it has always had such
infallible success, that I have no longer any doubt on
the certainty of the results which it has afforded.
It is true that I have been in possession of all the
assistance which was necessary for me; and my
situation and assiduous search for nearly thirty years
have procured for me skeletons of every genus and
kind of quadrupeds, and even of many species in
certain genera, and many individuals in certain species.
With such means, I have had much ease in multiplying
my comparisons, and of verifying, in all their details,
the applications that I made of my laws.
We cannot now dwell longer on this method, and are
compelled to refer to the larger comparative anatomy
which we shall soon produce, and which will contain
all these rules. However, an intelligent reader will be
still able to derive a vast many from the work on fossil
bones, if he will take the trouble to follow all the
applications there laid down. He will see that it is by
this methtd alone that we have been guided, and have
always found it sufficient to classify each bone with its
species, when it was aliving species; to its genera,
when it was of an unknown

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species; to its order, when it was of a new genus; and
finally, to its class, when it belonged to an order not
yet established; and also to assign it, in these last three
cases, the proper characteristics to distinguish it from
the orders, genera, or species most resembling it.
Naturalists before us did no more for entire animals.
Thus we have determined and classed the remains of
more than one hundred and fifty mammiferous and
oviparous quadrupeds.

THE GENERAL RESULTS OF THESE RESEARCHES.

Considered relatively to the species, more than
ninety of these animals are certainly unknown to
present naturalists; eleven or twelve have so exact a
resemblance to known species, that there can scarcely
be a doubt of their identity; others present, with the
known species, many points of similarity; but the
comparison has not been made with sufficient accuracy
to remove all scruples.
Considered with regard to genera, amongst the
ninety unknown species, there are nearly sixty which
belong to new genera; the other species be long to
known genera.
It is not unprofitable to consider these animals with
relation to the class and orders to which they belong.
Of the hundred and fifty species, about a fourth are
oviparous quadrupeds, and all the others are
mammiferous. Amongst these, more than half belong
to non-ruminating hoofed animals.
It would be premature to establish on these
researches any conclusion relative to the theory of the
earth; because they have not a necessary relation to the
members of the genera or species which may be

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embedded in our layers. Thus much has been gathered
from those bones of the larger species, which more
readily strike the workmen; whilst those of the smaller
are usually neglected, unless chance brings them into
the hands of a naturalist, or some striking
circumstance, such as their abounding in certain
places, should draw the attention of the common
observer.

RELATIONS OF THE SPECIES WITH THE STRATA.

What is more important, and is even the most
essential object of all my toil, and establishes the
actual relation with the theory of the earth, is to know
in what layers we find a particular species, and if there
be any general and relative laws, either relative to
zoological subdivisions, or to the greater or lesser
resemblance of the species with those of the present
day.
The recognised laws in this respect are very
remarkable and very clear.
First, it is certain that oviparous quadrupeds appear
much more frequently than viviparous; that they are
ever more abundant, larger, and more various, in the
older layers, than at the actual surface of the globe.
The ichthyosauri, the plesiosauri, many tortoises,
many crocodiles, are beneath the chalk in the
formations commonly called those of Jura. The
monitors of Thuringia would be still more ancient, if,
as is the opinion of the school of Werner, the copper
slate which includes them, in the midst of so many
sorts of fishes which are supposed to be of fresh water
origin, is amongst the most ancient beds

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of secondary formations. The immense crocodiles and
great tortoises of Maestricht are in the chalky layer;
but these are marine animals. This first appearance of
fossil bones seems then to prove, that there were dry
lands and fresh waters before the formation of the
chalk; but, neither at that epoch, nor whilst the chalk
was forming, nor even long afterwards, was it
incrusted with the relics of terrestrial mammifera; or
at least the small number of those which it is alleged
have been found, form only an exception perfectly
inconsequential.
We begin to find the bones of marine mammifera,
that is, of lamantins and seals, in the thick shelly
limestone, which is above the chalk in the
neighbourhood of Paris; but there is no bone of a
terrestrial mammiferous animal.
In spite of the most indefatigable researches, I have
found it impossible to discover any distinct trace of
this class prior to the layers deposited on the coarser
limestone; lignites and molasses certainly have them;
but I much doubt whether these earths are all, as is
believed, anterior to the limestone; the places where
they have furnished bones are too limited, too few, but
that we may suppose there is some irregularity or some
recurrence in their formation. On the contrary, when
we reach the deposites immediately above the
limestone, the bones of terrestrial animals appear in
great numbers.
Thus as it is rational to believe that shells and fishes
did not exist at the period of the formation of the
primordial layers, we may also believe that the
oviparous quadrupeds began with fishes, and from the
first production of secondary formations; but that
terrestrial quadrupeds have not appeared, at least in
considerable numbers, until a long time,

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afterwards, and when the limestone which now
contains the greater portion of our genera of shells,
although different in species from our own, had been
deposited.
We must remark, that these coarse limestone strata,
which we make use of in Paris for building, are the
last banks which denote a long and peaceful flowing of
the sea over our own continents. After them we find
layers filled with shells and other marine productions;
but these consist of shifting layers, sands, maria, sand-
stones, soft clays, which rather denote changes more or
less sudden, than a quiet settling; and if there be any
stony or regular banks of any size beneath or above
these moving layers, they generally betray marks of
having been deposited from fresh water.
Nearly all the known bones of viviparous
quadrupeds are then either in these deposites of fresh
water, or in alluvial deposites; and consequently there
is reason to believe that these quadrupeds had not
begun to exist, or at least, to leave these relics in the
layers that we are able to fathom, till after the last
retreat but one of the sea, and during that state of
things which had preceded its last irruption.
But there is also an order in the arrangement of
these bones amongst themselves; and this order
bespeaks a very remarkable succession in their species.
First, all the unknown genera, the palæotheria, the
anoplotheria, &c. on the relative situation of which we
have certain ideas, belong to the oldest of the layers in
question; to those which rest immediately above the
coarse limestone. It is these, principally, which fill the
regular banks, deposited by soft waters or certain
shifting beds, very

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anciently formed, and generally composed of sand and
round flints, and which were probably the first alluvial
deposites of the ancient world. We find with them
certain lost species of known kinds, but in small
numbers, and some oviparous quadrupeds and fishes,
which all appear in fresh water. The beds which
contain them are always more or less covered over by
the shifting beds, filled with shells and other marine
productions.
The most celebrated of these unknown species,
which belong to the known kinds, or to kinds very
much resembling those that are known, such as the
fossil elephant, the rhinoceros, the hippopotamus, and
the mastodons, are not found amongst the more ancient
kinds. It is only in the shifting layers that they are
discovered, sometimes with sea-shells, sometimes with
the shells of fresh water, but never in the regular stony
beds. All that is found with these species is either
unknown as they are, or at least doubtful.
In fact, the bones of the species which appear the
same as ours, only present themselves in the last
deposites of alluvions formed on the banks of the
rivers, or on the beds of old ponds, or dried marshes,
or in the depths of turf layers, or in the clefts and
hollows of certain rocks, or finally, at a short distance
from the surface, in places where they may have been
embedded by casualties or by the hand of man; and
their superficial position makes these bones, the most
recent of any, almost always in the worst state of
preservation. It must not, however, be supposed that
this classifying of different relative situations is as
clear as that of the species, nor that it can have a
demonstrative character equally distinct; there are
manifest causes why it cannot be so.