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divided into chambers by delicate saucer…shaped partitions；
situated at regular intervals one above the other。 Now there is
no mineral body which presents any structure comparable to this；
and the conclusion suggested itself that the Belemnites must be
the effects of causes other than those which are at work in
inorganic nature。 On close examination； the saucer…shaped
partitions were proved to be all perforated at one point； and
the perforations being situated exactly in the same line； the
chambers were seen to be traversed by a canal； or
siphuncle； which thus connected the smallest or aphical
chamber with the largest。 There is nothing like this in the
vegetable world； but an exactly corresponding structure is met
with in the shells of two kinds of existing animals； the pearly
Nautilus and the Spirula； and only in them。 These
animals belong to the same divisionthe Cephalopodaas
the cuttle…fish； the squid； and the octopus。 But they are the
only existing members of the group which possess chambered；
siphunculated shells； and it is utterly impossible to trace any
physiological connection between the very peculiar structural
characters of a cephalopod and the presence of a chambered
shell。 In fact； the squid has； instead of any such shell； a
horny 〃pen；〃 the cuttlefish has the so…called 〃cuttle…bone；〃 and
the octopus has no shell； or； at most； a mere rudiment of one。
Nevertheless； seeing that there is nothing in nature at all like
the chambered shell of the Belemnite； except the shells of the
Nautilus and of the Spirula； it was legitimate to
prophesy that the animal from which the fossil proceeded must
have belonged to the group of the Cephalopoda。
Nautilus and Spirula are both very rare animals；
but the progress of investigation brought to light the singular
fact； that； though each has the characteristic cephalopodous
organisation； it is very different from the other。 The shell of
Nautilus is external； that of Spirula internal；
Nautilus has four gills； Spirula two；
Nautilus has multitudinous tentacles； Spirula has
only ten arms beset with horny…rimmed suckers； Spirula；
like the squids and cuttle…fishes； which it closely resembles；
has a bag of ink which it squirts out to cover its retreat when
alarmed； Nautilus has none。
No amount of physiological reasoning could enable any one to say
whether the animal which fabricated the Belemnite was more like
Nautilus； or more like Spirula。 But the accidental
discovery of Belemnites in due connection with black elongated
masses which were： certainly fossilised ink…bags； inasmuch as
the ink could be ground up and used for painting as well as if
it were recent sepia； settled the question； and it became
perfectly safe to prophesy that the creature which fabricated
the Belemnite was a two…gilled cephalopod with suckers on its
arms； and with all the other essential features of our living
squids； cuttle…fishes； and Spirulae。 The palaeontologist
was； by this time； able to speak as confidently about the animal
of the Belemnite； as Zadig was respecting the queen's spaniel。
He could give a very fair description of its external
appearance； and even enter pretty fully into the details of its
internal organisation； and yet could declare that neither he；
nor any one else； had ever seen one。 And as the queen's spaniel
was found； so happily has the animal of the Belemnite； a few
exceptionally preserved specimens have been discovered； which
completely verify the retrospective prophecy of those who
interpreted the facts of the case by due application of the
method of Zadig。
These Belemnites flourished in prodigious abundance in the seas
of the mesozoic； or secondary； age of the world's geological
history； but no trace of them has been found in any of the
tertiary deposits； and they appear to have died out towards the
close of the mesozoic epoch。 The method of Zadig； therefore；
applies in full force to the events of a period which is
immeasurably remote； which long preceded the origin of the most
conspicuous mountain masses of the present world； and the
deposition； at the bottom of the ocean； of the rocks which form
the greater part of the soil of our present continents。
The Euphrates itself； at the mouth of which Oannes landed； is a
thing of yesterday compared with a Belemnite； and even the
liberal chronology of magian cosmogony fixes the beginning of
the world only at a time when other applications of Zadig's
method afford convincing evidence that； could we have been there
to see； things would have looked very much as they do now。
Truly the magi were wise in their generation； they foresaw
rightly that this pestilent application of the principles of
common sense； inaugurated by Zadig； would be their ruin。
But it may be said that the method of Zadig； which is simple
reasoning from analogy； does not account for the most striking
feats of modern palaeontologythe reconstruction of entire
animals from a tooth or perhaps a fragment of a bone； and it may
be justly urged that Cuvier； the great master of this kind of
investigation； gave a very different account of the process
which yielded such remarkable results。
Cuvier is not the first man of ability who has failed to make
his own mental processes clear to himself； and he will not be
the last。 The matter can be easily tested。 Search the eight
volumes of the 〃Recherches sur les Ossemens Fossiles〃 from cover
to cover； and nothing but the application of the method of Zadig
will be found in the arguments by which a fragment of a skeleton
is made to reveal the characters of the animal to which
it belonged。
There is one well…known case which may represent all。 It is an
excellent illustration of Cuvier's sagacity； and he evidently
takes some pride in telling his story about it。 A split slab of
stone arrived from the quarries of Montmartre； the two halves of
which contained the greater part of the skeleton of a small
animal。 On careful examinations of the characters of the teeth
and of the lower jaw； which happened to be exposed； Cuvier
assured himself that they presented such a very close
resemblance to the corresponding parts in the living opossums
that he at once assigned the fossil to that genus。
Now the opossums are unlike most mammals in that they possess
two bones attached to the fore part of the pelvis； which are
commonly called 〃marsupial bones。〃 The name is a misnomer；
originally conferred because it was thought that these bones
have something to do with the support of the pouch； or
marsupium； with which some； but not all； of the opossums are
provided。 As a matter of fact； they have nothing to do with the
support of the pouch； and they exist as much in those opossums
which have no pouches as in those which possess them。 In truth；
no one knows what the use of these