The Reptilia cannot, it must be acknowledged, offer such ostensible sources
of amusement or interest as these : but to the philosophical student of Nature,—
to him who seeks in his investigations for something beyond the mere gratification
of the eye and ear, or the amusement to be derived from watching the
changes of an insect, or the nidification of a bird,—to him, in short, who, in the
expanded and almost boundless' view of Nature which lies before him, endeavours
to trace something of the great plan on which this world of life has been
organized, and to ascertain the very principles of that mighty and harmonious
system, of which every variety of form, and every grade of organization: constitutes
an essential part,—no class of beings, however forbidding their outward
appearance may be, or with whatever, attributes of dread and disgust superstition
may have invested them, can be otherwise than interesting, and deserving
the most careful and profound investigation.
It is obvious that in proportion to the extent of our acquaintance, not only
with those types of form which indicate the centres of the different groups,
but with the nicer gradations of 'structure which form the passage from one
group to another, or the links by which they are associated, will be our means
of advancing in the pursuit of this most important and interesting object, , to
which the anxious attention of eyery true naturalist has been directed, from
Aristotle downwards to MacLeay. Tt is not that every species of a group—■
especially of some of the most extensive, and which contain numerous species
of nearly the same form,—can be viewed as equally important: the decision, for
instance, of every doubtful species of the Colubridae would he hut a/trifling
and unimportant addition to our knowledge, with respect to the great object
to which I have alluded;, yet how often does it happen that an individual
which, from superficial examination perhaps, or from the want of comparison,
had been considered as isolated and bearing no near or important relation, to
any other form, proves, by the discovery of other intermediate species, or by
further investigation of its own characters, to he the essential link in some
important chain of affinity, or the analogical key to some corresponding form
in another group. The distinct and certain settlement of disputed synonymy,
too, cannot be considered as a very important object of the labours of the
naturalist; yet even this, to an orderly and well-regulated mind, will be a source
of no small satisfaction ; whilst the results, in the elucidation of the geographical
distribution of animals, and still more in ascertaining the identity or diversity
of recent and fossil species, give to this more humble branch of our zoological
studies, an importance which does not at first sight appertain to it.
To all these objects the writer of Monographs essentially contributes. He
acts as the pioneer, removing obstacles, and clearing the ground to be afterwards
occupied by the more efficient force, whose evolutions would be continually
impeded and their plans disordered, but for the assistance of their
laborious predecessors.
In composing a Monograph of the present Order, there is no difficulty in ascertaining
its exact limits, nor danger of committing the’error either of introducing
an individual belonging to any approximating group, or of rejecting as doubtful
any one which really appertains to this. There is in fact scarcely any group
of animals which, according to our present knowledge, is so distinctly circumscribed
by peculiarity of structure, as the: Testudinata. The circumstance of
the bmbs being placed within instead of on the outside of the trunk, and the
osseous union of the ribs, forming a sort of bony box, including not only the
viscera but the members, are characters which at once séparate them from every
other known group. Whether future investigations, either in recent or especially
in fossil zoology, máy discover the links by which these singular animals
are connected, by continuous affinity, with any of the groups from which at
present they appear to be so distinctly separated, we cannot now even conjecture
; but at present they certainly remain the most isolated order, not only
amongst the Reptilia, but perhaps in the whole animal kingdom.
As the species’which inhabit the Continent of Europe and the seas which
were navigated by its ancient inhabitants, are but few, we look in vain to the
Classical writers on natural subjects for any but the most vague and uncertain
notices respecting them. That the four species of marine turtles were known
both to the Greeks and Romans, is indeed scarcely to be doubted, as three of
them are occasionally found in the Mediterranean, and the fourth, Chelonia
imbricata, furnished their merchants with the precious tortoise-shell,—an article
of luxurious decoration, which appears to have been much used in ornamenting
the palaces and villas of the Roman nobles. The soft-bodied species of this