CHAPTER VII

.

ANIMAL MORPHOLOGY.

THE subject of Animal Morphology has recently been expanded into a form strikingly comprehensive and systematic by Mr. Owen; and supplied by him with a copious and carefully-chosen language; which in his hands facilitates vastly the comparison and appreciation of the previous labors of physiologists, and opens the way to new truths and philosophical generalizations. Though the steps which have been made had been prepared by previous anatomists, I will borrow my view of them mainly from him; with the less scruple, inasmuch as he has brought into full view the labors of his predecessors.

I have stated in the History that the skeletons of all vertebrate animals are conceived to be reducible to a single Type, and the skull reducible to a series of vertebræ. But inasmuch as this reduction includes not only a detailed correspondence of the bones of man with those of beasts, but also with those of birds, fishes, and reptiles, it may easily be conceived that the similarities and connexions are of a various and often remote kind. The views of such relations, held by previous Comparative Anatomists, have led to the designations of the bones of animals which have been employed in anatomical descriptions; and these designations having been framed and adopted by anatomists looking at the subject from different sides, and having different views of analogies and relations, have been very various and unstable; besides being often of cumbrous length and inconvenient form.

The corresponding parts in different animals are called _homologues_, {639} a term first applied to anatomy by the philosophers of Germany; and this term Mr. Owen adopts, to the exclusion of terms more loosely denoting identity or similarity. And the Homology of the various bones of vertebrates having been in a great degree determined by the labors of previous anatomists, Mr. Owen has proposed names for each of the bones: the condition of such names being, that the homologues in all vertebrates shall be called by the same name, and that these names shall be founded upon the terms and phrases in which the great anatomists of the 16th, 17th, and 18th centuries expressed the results of their researches respecting the human skeleton. These names, thus selected, so far as concerned the bones of the Head of Fishes, one of the most difficult cases of this Special Homology, he published in a Table,[44\B] in which they were compared, in parallel columns, with the names or phrases used for the like purpose by Cuvier, Agassiz, Geoffroy, Hallman, Sœmmering, Meckel, and Wagner. As an example of the considerations by which this selection of names was determined, I may quote what he says with regard to one of these bones of the skull.

[Note 44\B: _Lectures on Vertebrates_. 1846, p. 158. And _On the Archetype and Homologies of the Vertebrate Skeleton_. 1848, p. 172.]

"With regard to the 'squamosal' (_squamosum_. Lat. pars squamosa ossis temporis.--Sœmmering), it might be asked why the term 'temporal' might not be retained for this bone. I reply, because that term has long been, and is now universally, understood in human anatomy to signify a peculiarly anthropotomical coalesced congeries of bones, which includes the 'squamosal' together with the 'petrosal,' the 'tympanic,' the 'mastoid,' and the 'stylohyal.' It seems preferable, therefore, to restrict the signification of the term 'temporal' to the whole (in Man) of which the 'squamosal' is a part. To this part Cuvier has unfortunately applied the term 'temporal' in one class, and 'jugal' in another; and he has also transferred the term 'temporal' to a third equally distinct bone in fishes; while to increase the confusion M. Agassiz has shifted the name to a fourth different bone in the skull of fishes. Whatever, therefore, may be the value assigned to the arguments which will be presently set forth, as to the special homologies of the 'pars squamosa ossis temporis,' I have felt compelled to express the conclusion by a definite term, and in the present instance, have selected that which recalls the best accepted anthropomorphical designation of the part; although 'squamosal' must be understood and applied in an arbitrary sense; and not as descriptive of a scale-like {640} form; which in reference to the bone so called, is rather its exceptional than normal figure in the vertebrate series."

The principles which Mr. Owen here adopts in the selection of names for the parts of the skeleton are wise and temperate. They agree with the aphorisms concerning the language of science which I published in the _Philosophy of the Inductive Sciences_; and Mr. Owen does me the great honor of quoting with approval some of those Aphorisms. I may perhaps take the liberty of remarking that the system of terms which he has constructed, may, according to our principles, be called rather a _Terminology_ **than a _Nomenclature_: that is, they are analogous more nearly to the _terms_ by which botanists describe the parts and organs of plants, than to the _names_ by which they denote genera and species. As we have seen in the History, plants as well as animals are subject to morphological laws; and the names which are given to organs in consequence of those laws are a part of the Terminology of the science. Nor is this distinction between Terminology and Nomenclature without its use; for the rules of prudence and propriety in the selection of words in the two cases are different. The Nomenclature of genera and species may be arbitrary and casual, as is the case to a great extent in Botany and in Zoology, especially of fossil remains; names being given, for instance, simply as marks of honor to individuals. But in a Terminology, such a mode of derivation is not admissible: some significant analogy or idea must be adopted, at least as the origin of the name, though not necessarily true in all its applications, as we have seen in the case of the "squamosal" just quoted. This difference in the rules respecting two classes of scientific words is stated in the _Aphorisms_ xiii. and xiv. _concerning the Language of Science_.

Such a Terminology of the bones of the skeletons of all vertebrates as Mr. Owen has thus propounded, cannot be otherwise than an immense acquisition to science, and a means of ascending from what we know already to wider truths and new morphological doctrines.

With regard to one of these doctrines, the resolution of the human head into vertebræ, Mr. Owen now regards it as a great truth, and replies to the objections of Cuvier and M. Agassiz, in detail.[45\B] He gives a Table in which the Bones of the Head are resolved into four vertebræ, which he terms the Occipital, Parietal, Frontal, and Nasal Vertebra, respectively. These four vertebræ agree in general with what Oken called the Ear-vertebra, the Jaw-vertebra, the Eye-vertebra, and {641} the Nose-vertebra, in his work _On the Signification of the Bones of the Skull_, published in 1807: and in various degrees, with similar views promulgated by Spix (1815), Bojanus (1818), Geoffroy (1824), Carus **(1828). And I believe that these views, bold and fanciful as they at first appeared, have now been accepted by most of the principal physiologists of our time.

[Note 45\B: _Archetype and Homologies of the Vertebrate Skeleton_. 1848, p. 141.]

But another aspect of this generalization has been propounded among physiologists; and has, like the others, been extended, systematized, and provided with a convenient language by Mr. Owen. Since animal skeletons are thus made up of vertebræ and their parts are to be understood as developements of the parts of vertebræ, Geoffroy (1822), Carus (1828), Müller (1834), Cuvier (1836), had employed certain terms while speaking of such developements; Mr. Owen in the _Geological Transactions_ in 1838, while discussing the osteology of certain fossil Saurians, used terms of this kind, which are more systematic than those of his predecessors, and to which he has given currency by the quantity of valuable knowledge and thought which he has embodied in them.

According to his Terminology,[46\B] a vertebra, in its typical completeness, consists of a central part or _centrum_; at the back of this, two plates (the _neural apophyses_) and a third outward projecting piece (the _neural spine_), which three, with the centrum, form a canal for the spinal marrow; at the front of the centrum two other plates (the _hæmal apophyses_) and a projecting piece, forming a canal for a vascular trunk. Further lateral elements (_pleuro-apophyses_) and other projections, are in a certain sense dependent on these principal bones; besides which the vertebra may support _diverging appendages_. These parts of the vertebra are fixed together, so that a vertebra is by some anatomists described as a single bone; but the parts now mentioned are usually developed from distinct and independent centres, and are therefore called by Mr. Owen "autogenous" elements.

[Note 46\B: _Archetype and Homologies of the Vertebrate Skeleton_. 1848, p. 81.]

The _General_ Homology of the vertebral skeleton is the reference of all the parts of a skeleton to their true types in a series of vertebræ: and thus, as _special_ homology refers all the parts of skeletons to a given type of skeleton, say that of Man, _general_ homology refers all the parts of every skeleton, say that of Man, to the parts of a series of Vertebræ. And thus as Oken propounded his views of the Head as a resolution of the Problem of _the Signification of the Bones of the Head_, {642} so have we in like manner, for the purposes of General Homology, to solve the Problem of _the Signification of Limbs_. The whole of the animal being a string of vertebræ, what are arms and legs, hands and paws, claws and fingers, wings and fins, and the like? This inquiry Mr. Owen has pursued as a necessary part of his inquiries. In giving a public lecture upon the subject in 1849,[47\B] he conceived that the phrase which I have just employed would not be clearly apprehended by an English Audience, and entitled his Discourse "On the _Nature_ of Limbs:" and in this discourse he explained the modifications by which the various kinds of limbs are derived from their rudiments in an archetypal skeleton, that is, a mere series of vertebræ without head, arms, legs, wings, or fins.

[Note 47\B: _On the Nature of Limbs_, a discourse delivered at a Meeting of the Royal Institution, 1849.]

_Final Causes_

It has been mentioned in the History that in the discussions which took place concerning the Unity of Plan of animal structure, this principle was in some measure put in opposition to the principle of Final Causes: Morphology was opposed to Teleology. It is natural to ask whether the recent study of Morphology has affected this antithesis.

If there be advocates of Final Causes in Physiology who would push their doctrines so far as to assert that every feature and every relation in the structure of animals have a purpose discoverable by man, such reasoners are liable to be perpetually thwarted and embarrassed by the progress of anatomical knowledge; for this progress often shows that an arrangement which had been explained and admired with reference to some purpose, exists also in cases where the purpose disappears; and again, that what had been noted as a special teleological arrangement is the result of a general morphological law. Thus to take an example given by Mr. Owen: that the ossification of the head originates in several centres, and thus in its early stages admits of compression, has been pointed out as a provision to facilitate the birth of viviparous animals; but our view of this provision is disturbed, when we find that the same mode of the formation of the bony framework takes place in animals which are born from an egg. And the number of points from which ossification begins, depends in a wider sense on the general homology of the animal frame, according to which each part is composed of a certain number of autogenous vertebral elements. In this {643} way, the admission of a new view as to Unity of Plan will almost necessarily displace or modify some of the old views respecting Final Causes.

But though the view of Final Causes is displaced, it is not obliterated; and especially if the advocate of Purpose is also ready to admit visible correspondences which have not a discoverable object, as well as contrivances which have. And in truth, how is it possible for the student of anatomy to shut his eyes to either of these two evident aspects of nature? The arm and hand of man are made for taking and holding, the wing of the sparrow is made for flying; and each is adapted to its end with subtle and manifest contrivance. There is plainly Design. But the arm of man and the wing of the sparrow correspond to each other in the most exact manner, bone for bone. Where is the Use or the Purpose of this correspondence? If it be said that there may be a purpose though we do not see it, that is granted. But Final Causes _for us_ are contrivances of which _we see_ the end; and nothing is added to the evidence of Design by the perception of a unity of plan which in no way tends to promote the design.

It may be said that the design appears in the modification of the plan in special ways for special purposes;--that the vertebral plan of an animal being given, the fore limbs are modified in Man and in Sparrow, as the nature and life of each require. And this is truly said; and is indeed the truth which we are endeavoring to bring into view:--that there are in such speculations, two elements; one given, the other to be worked out from our examination of the case; the _datum_ and the _problem_; the homology and the teleology.

Mr. Owen, who has done so much for the former of these portions of our knowledge, has also been constantly at the same time contributing to the other. While he has been aiding our advances towards the Unity of Nature, he has been ever alive to the perception of an Intelligence which pervades Nature. While his morphological doctrines have moved the point of view from which he sees Design, they have never obscured his view of it, but, on the contrary, have led him to present it to his readers in new and striking aspects. Thus he has pointed out the final purposes in the different centres of ossification of the long bones of the limbs of mammals, and shown how and why they differ in this respect from reptiles (_Archetype_, p. 104). And in this way he has been able to point out the insufficiency of the rule laid down both by Geoffroy St. Hilaire and Cuvier, for ascertaining the true number of bones in each species. {644}

Final Causes, or Evidences of Design, appear, as we have said, not merely as contrivances for evident purposes, but as modifications of a given general Plan for special given ends. If the general Plan be discovered after the contrivance has been noticed, the discovery may at first seem to obscure our perception of Purpose; but it will soon be found that it merely transfers us to a higher point of view. The adaptation of the Means to the End remains, though the Means are parts of a more general scheme than we were aware of. No generalization of the Means can or ought permanently to shake our conviction of the End; because we must needs suppose that the Intelligence which contemplates the End is an intelligence which can see at a glance along a vista of Means, however long and complex. And on the other hand, no special contrivance, however clear be its arrangement, can be unconnected with the general correspondences and harmonies by which all parts of nature are pervaded and bound together. And thus no luminous teleological point can be extinguished by homology; nor, on the other hand, can it be detached from the general expanse of homological light.

The reference to Final Causes is sometimes spoken of as unphilosophical, in consequence of Francis Bacon's comparison of Final Causes in Physics to Vestal Virgins devoted to God, and barren. I have repeatedly shown that, in Physiology, almost all the great discoveries which have been made, have been made by the assumption of a purpose in animal structures. With reference to Bacon's simile, I have elsewhere said that if he had had occasion to develope its bearings, full of latent meaning as his similes so often are, he would probably have said that to those Final Causes barrenness was no reproach, seeing they ought to be not the Mothers but the Daughters of our Natural Sciences; and that they were barren, not by imperfection of their nature, but in order that they might be kept pure and undefiled, and so fit ministers in the temple of God. I might add that in Physiology, if they are not Mothers, they are admirable Nurses; skilful and sagacious in perceiving the signs of pregnancy, and helpful in bringing the Infant Truth into the light of day.

There is another aspect of the doctrine of the Archetypal Unity of Composition of Animals, by which it points to an Intelligence from which the frame of nature proceeds; namely this:--that the Archetype of the Animal Structure being of the nature of an _Idea_, implies a mind in which this Idea existed; and that thus Homology itself points the way to the Divine Mind. But while we acknowledge the full {645} value of this view of theological bearing of physiology, we may venture to say that it is a view quite different from that which is described by speaking of "Final Causes," and one much more difficult to present in a lucid manner to ordinary minds.

{{646}}

## BOOK XVIII.

GEOLOGY.

WITH regard to Geology, as a Palætiological Science, I do not know that any new light of an important kind has been thrown upon the general doctrines of the science. Surveys and examinations of special phenomena and special districts have been carried on with

## activity and intelligence; and the animals of which the remains

people the strata, have been reconstructed by the skill and knowledge of zoologists:--of such reconstructions we have, for instance, a fine assemblage in the publications of the Palæontological Society. But the great questions of the manner of the creation and succession of animal and vegetable species upon the earth remain, I think, at the point at which they were when I published the last edition of the History.

I may notice the views propounded by some chemists of certain bearings of Mineralogy upon Geology. As we have, in mineral masses, organic remains of former organized beings, so have we crystalline remains of former crystals; namely, what are commonly called _pseudomorphoses_--the shape of one crystal in the substance of another. M. G. Bischoff[48\B] considers the study of pseudomorphs as important in geology, and as frequently the only means of tracing processes which have taken place and are still going on in the mineral kingdom.

[Note 48\B: _Chemical and Physical Geology_.]

I may notice also Professor Breithaupt's researches on the order of succession of different minerals, by observing the mode in which they occur and the order in which different crystals have been deposited, promise to be of great use in following out the geological changes which the crust of the globe has undergone. (_Die Paragenesis der Mineralien_. Freiberg. 1849.)

In conjunction with these may be taken M. de Senarmont's experiments on the formation of minerals in veins; and besides Bischoff's {647} _Chemical Geology_, Sartorius von Walterhausen's Observations on the occurrence of minerals in Amygdaloid.

As a recent example of speculations concerning Botanical Palætiology, I may give Dr. Hooker's views of the probable history of the Flora of the Pacific.

In speculating upon this question, Dr. Hooker is led to the discussion of geological doctrines concerning the former continuity of tracts of land which are now separate, the elevation of low lands into mountain ranges in the course of ages, and the like. We have already seen, in the speculations of the late lamented Edward Forbes, (see Book xviii. chap. vi. of this History,) an example of a hypothesis propounded to account for the existing Flora of England: a hypothesis, namely, of a former Connexion of the West of the British Isles with Portugal, of the Alps of Scotland with those of Scandinavia, and of the plains of East Anglia with those of Holland. In like manner Dr. Hooker says (p. xxi.) that he was led to speculate on the possibility of the plants of the Southern Ocean being the remains of a Flora that had once spread over a larger and more continuous tract of land than now exists in the ocean; and that the peculiar Antarctic genera and species may be the vestiges of a Flora characterized by the predominance of plants which are now scattered throughout the Southern islands. He conceives this hypothesis to be greatly supported by the observations and reasonings of Mr. Darwin, tending to show that such risings and sinkings are in active progress over large portions of the continents and islands of the Southern hemisphere: and by the speculations of Sir C. Lyell respecting the influence of climate on the migrations of plants and animals, and the influence of geological changes upon climate.

In Zoology I may notice (following Mr. Owen)[49\B] recent discoveries of the remains of the animals which come nearest to man in their structure. At the time of Cuvier's death, in 1832, no evidence had been obtained of fossil Quadrumana; and he supposed that these, as well as Bimana, were of very recent introduction. Soon after, in the oldest (eocene) tertiary deposits of Suffolk, remains were found proving the existence of a monkey of the genus Macacus. In the Himalayan tertiaries were found petrified bones of a Semnopithecus; in Brazil, remains of an extinct platyrhine monkey of great size; and lastly, in the middle tertiary series of the South of France, was discovered a fragment of the jaw of the long-armed ape (_Hylobates_). But no fossil human {648} remains have been discovered in the regularly deposited layers of any divisions (not even the pleiocene) of the tertiary series; and thus we have evidence that the placing of man on the earth was the last and peculiar act of Creation.

[Note 49\B: _Brit. Asso._ 1854, p. 112.]

THE END.

Transcriber's Notes

Whewell's book was originally published in 3 volumes in London in 1837. A second edition appeared in 1847, and a third in 1857. A 2-volume version of the 3rd edition was published in New York in 1858, reprinted 1875. This Project Gutenberg text, combining both volumes in sequence, was derived from the 1875 version, relying upon resources kindly provided by the Internet Archive.

Three items have been added to the Contents of the First Volume; they are marked off by ~ ~, as are any other additions to the text.

Printed page numbers have been transcribed in { }; pages without a printed number have been indicated by {{ }}. Where words were hyphenated across pages, the number has been placed before the word.

Fractions have been transcribed as numerator/denominator, occasionally using parentheses to disambiguate. The original sometimes has numerator over a line with denominator below, at other times numerator hyphen denominator. Superscripted characters are marked by a ^ before the character.

Footnotes in the original text were numbered by chapter; here they have been numbered by Book (the number of which is given after a \, for the two appendices to the 3rd edition A has been used for volume 1, B for volume 2). They are placed after the paragraph in which they occur, and are transcribed [Note m\n: ...]. Footnote anchors are transcribed [m\n]. All other square brackets are in the original text.

One difficult item is the use of numbers within a ring as names of asteroids; here the numbers are in ( ).

Corrections to the text have been marked with **. They are listed below, and were usually confirmed by reference to English printings of the text. Inconsistencies, especially with respect to accents and formatting, are numerous and have in general not been adjusted, though Greek quotations have been checked against other versions where available. Nor have Whewell's unbalanced quotation marks been modernised. The English versions have been used to restore Whewell's "gesperrt" emphases in some Greek passages.

Location 1875 Text Correction Vol. 1 p. 25 Cruikshanks Cruickshank p. 30 19 65 p. 30 : ; p. 33 (thrice) 184 182 p. 36 184 182 p. 71 Arisotelians Aristotelians p. 75 " p. 79 σερματικοὶ σπερματικοὶ p. 101 " note 1\2 6 7 p. 175 ecliptical elliptical note 1\4 iv. vi. note 75\4 Summæ Summa note 10\5 iii. iv. p. 271 (twice) Mastlin Mæstlin p. 282 _Dialogo "_Dialogo p. 284 semil semel p. 287 endeaver endeavor note 7\6 1. i. note 8\6 Dial. i. p. 40. p. 141. note 9\6 _Speculutionum _Speculationum p. 325 Gualtier Gualter p. 341 and 342 Marsenne Mersenne p. 374 of p. 377 prependicularity perpendicularity p. 403 " note 30\7 Cosmotheros Cosmotheoros p. 415 _casual_ _causal_ p. 416 ) p. 419 ] p. 431 _a_ a note 69\7 1453 1753 note 84\7 Ast. Ass. p. 463 Philosphical Philosophical p. 471 ] p. 564 prevalance prevalence Vol. 2 p. 50 Ὑφιφάνη Ὑψιφάνη ἄρισπον ἄριστον οὔδιον εὔδιον p. 84 ] p. 85 viii. vii. p. 115 1853 1823 p. 149 , . p. 162 Footnote number missing in text p. 201 stream steam p. 213 and note 39\11 same number as the preceding note p. 240 Cruikshanks Cruickshank note 18\13 Mass-bestimmengen Mass-bestimmungen p. 264 in is note 11\14 _Stahl Stahl p. 295 the _the note 78\14 the entire text of this note is missing p. 301 lecture lectures note 87\14 96. 963. note 92\14 153 853 p. 330 Angels Angles p. 336 given giving p. 343 " p. 394 Surien Surian p. 411 _Couérs Elmentaire_ _Cours Elémentaire_ note 136\16 Εἴδην Εἴδη p. 450 dependance dependence p. 457 sucking-beasts suckling-beasts note 80\17 ählich ähnlich note 89\17 229 129 p. 477 osseuze osseuse note 119\17 229 299* p. 508 Lythophylaccii Lythophylacii p. 511 Stukely Stukeley note 18\18 Géognastique Géognostique p. 513 Sabapennine Sub-Apennine p. 514 Schlotheim Schlottheim p. 530 , ( ,) p. 556 Poissons Poisson's p. 620 iv. vii. p. 624 [ ( p. 628 in (not italicised in text) p. 630 Nordenskiold's Nordenskiöld's p. 638 390 474 p. 640 then than p. 641 1828 (1828)

* This is the page number given in the English edition. In the only version of the text referred to that I have found, the quotation is in a footnote on page 352 of the second edition (1805); the note was not in the first edition.