The Bridgewater Treatises
on the Power, Wisdom, and Goodness of God,
As Manifested in the Creation.
ANIMAL AND VEGETABLE PHYSIOLOGY, CONSIDERED
WITH REFERENCE TO NATURAL THEOLOGY.
PETER MARK ROGET, M. D.
to the Royal Society, Fullerian Professor of Physiology in the
Royal Institution of Great Britain, Vice President of the Society
of Arts, Fellow of the Royal College of Physicians,
Consulting Physician to the Queen Charlotte's
Lying-in Hospital, and to the Northern
In Two Volumes
Lea & Blanchard,
This electronic edition prepared by Dr. David C. Bossard
from original documents in his personal library.
Copyright © 2006 by David C. Bossard.
DEDICATION v. v
INSCRIPTION vi. vi
PREFACE vii.-xii. vii
NOTICE xiii.-xv. xiii
LIST OF ENGRAVINGS
NOTE: Text images have a resolution of 100 ppi. High resolution
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OUTLINE OF CUVIER'S CLASSIFICATION OF ANIMALS WITH EXAMPLES OF ANIMALS
BELONGING TO EACH DIVISION xxxi. xxxi
CHAPTER I. -- FINAL CAUSES
CHAPTER II. -- THE FUNCTIONS OF
LIFE 39 039
 An hypothesis has been advanced that the original creation
of species has been successive, and took place in the order of their
relative complexity of structure; that the standard types have arisen
the one from the other; that each succeeding form was an improvement
upon the preceding, and followed in a certain order of development,
according to a regular plan traced by the great Author of the universe
for bestowing perfection on his works. This gradation of structure was
necessarily accompanied by a gradation of faculties: the object of each
change of type being to attain higher objects, and to advance a farther
step towards the ultimate ends of the animal creation. Many apparent
anomalies, which are inexplicable upon any other supposition, are
easily reconcileable to this theory. The developments of structure
belonging to a particular type being always prospective, are not
completed in the inferior orders of the group formed upon that model,
but remain more or less imperfect, although each organ always fully
answers the particular purpose of the individual animal. But it
sometimes happens that the imperfection of an organ is so great, in
consequence of its development having proceeded to a very small extent,
as to render it wholly useless in that particular species, although in
a higher race of animals it fully performs its proper function. Thus we
shall find that rudiments of feet are contained within the bodies of
various kinds of serpents, which can obviously not be serviceable as
organs of progression. In the young of the whale, before its birth,
there is found in the lower jaw, a row of small teeth, which do not
rise above the gums, and can, therefore, be of no use as instruments of
mastication. Their farther growth is arrested, and they are afterwards
obliterated. This imperfect or rudimental condition of an organ
indicates its relation to other species belonging to the same type, and
demonstrates the existence of a general plan in their formation. ...
In following the transitions from one model of structure to another, we
often observe that a particular organ has been very greatly enlarged,
or otherwise modified to suit some particular purpose, foreign to its
usual destination, or to qualify it for performing some new office,
rendered necessary by the particular circumstances in which the animal
is placed. Thus, the ribs, which in quadrupeds are usually employed for
respiration, are in serpents converted into auxiliary organs of
progressive motion: and in the Draco volans, or flying lizard, they are
extended outwards from the sides to serve as wings. The teeth, usually
intended for mastication, are in many animals enlarged in order to
constitute weapons of offence, as in the Elephant, the Boar, the
Narwhal, and the Pristis. In like manner, in the Crustacea, organs of
the same general structure are converted sometimes into jaws, sometimes
into feelers, (or palpi,) and sometimes into feet; and the transition
from the one to the other is so gradual that it is difficult to draw a
proper distinction between them.
In pursuing the ascending series of animal structures we meet also with
instances of a contrary change, yet still resulting from the continued
application of the same principle. An organ which has served an
important purpose in one animal, may be of less use in another,
occupying a higher station in the scale, and the change of
circumstances may even render it wholly useless. In such cases we find
that it is gradually discarded from the system, becoming continually
smaller, till it disappears altogether. We may often, however, perceive
some traces of its existence, but only in a rudimental state, and as if
ready to be developed, when the occasion may demand it.
In the greater number of organic structures we may trace a tendency to
the repetition of certain organs, or parts, and the regular arrangement
of these similar portions either round a central axis, or in a
longitudinal series. The former is apparent in the verticulated organs
of plants, and in the radiated forms of zoophytes. The linear
arrangement is exhibited in the similar segments of annulose and other
articulated animals, and also in the pieces which compose the spinal
column of vertebrated animals. In these two latter classes, also, a
remarkable law of symmetry obtains in the formation of the two sides of
the body, which exhibits the lateral junction of similar but reversed
structures. The violations of this law are extremely rare; yet some
remarkable instances of anomalous formations, in this respect, will
hereafter be noticed.
I. -- THE MECHANICAL FUNCTIONS.
CHAPTER I. -- ORGANIC MECHANISM.
1. Organization in general
2. Vegetable Organization 60 060
3. Development of Vegetables 71 071
[072 Endogenous plant growth - example:
palms, corn (maize)] The whole stem, whatever height it may attain,
never increases its diameter after its outward layer has been
consolidated. ... The age of the tree may be estimated by the number of
circles, or knots which appear along its stem.
[075 Exogenous plant growth, example: oaks, many trees] The tree
continues to enlarge its trunk [annually].
4. Animal Organization 79 079
 Great efforts have been made by
physiologists to discover the particular structure which might be
considered as the simplest element of all the animal textures; the raw
material, as it were, with which the whole fabric is wrought: but their
labours have hitherto been fruitless.
>vessels, fibers, ligaments, tendons, cartilage, skeleton (shell or
bone), epidermis, cuticle, corium, hair, follicles, quills, fat
5. Muscular Power 97 097
CHAPTER II. -- THE MECHANICAL
FUNCTIONS IN ZOOPHITES.
CHAPTER III. -- MOLLUSCA.
CHAPTER IV. -- ARTICULATA.
CHAPTER V. -- INSECTS.
CHAPTER VI. -- VERTEBRATA.
CHAPTER VII. -- FISHES.
CHAPTER VIII. -- REPTILIA.
CHAPTER IX. -- MAMMALIA.
CHAPTER X. -- VERTEBRATA CAPABLE OF FLYING.