[432] There are two perfectly distinct aspects under which Living Beings may be studied–the Physiological and the Morphological. On the one hand, every living being exerts certain forces and performs certain acts or functions. It is the object of the physiologist to ascertain the precise mode in which these acts are performed, to refer them as far as possible to the ordinary laws of physics and chemistry, and when, as in many cases, the functions are highly complex, to analyse them into their elementary acts, and to determine by what part of the frame, by what special organs these are performed. With the form of these parts, with their connexion other than that which is involved in their coadjustment towards a common effect, the pure physiologist has no concern.

On the other hand, every living being has a definite form, and in all the higher living beings this form is complex; it is made up of a greater or smaller number of lesser parts, each of which has its own definite and appropriate figure. Now it is with these forms, with their mutual relations, with the laws which govern their association that morphology is alone concerned. Although in practice the two branches of biological science are commonly more or less united yet it would be quite possible to write a complete system of pure physiology without reference to morphology, and of morphology without reference to physiology. They are as distinct as in the mineral world are crystallography and chemistry. To put the case in another way. The different parts of every living being are but mutually related, they are subject to definite laws of correlation, but these laws of correlation are of two kinds essentially independent of [433] one another: there are physiological correlations and there are morphological correlations. Thus the teeth and the stomach are physiologically correlated, contributing as they do to the common end of alimentation; and inasmuch as this coadaptation towards a common end is the very essence of physiological correlation, the latter has sometimes received the name of rational correlation; for when the result to which a combination tends is obvious, we commonly imagine we can see the reason for that combination.

Since the validity of nine-tenths of the science of animal physiology involves the admission, that multitudes of the parts of animals are organs working towards a common end, I do not suppose that it ever has entered, or ever will enter, into the mind of any person conversant with the rudiments of that science to question the existence of physiological correlation between the different parts of animals. But how far that correlation is in any case to be called necessary; that is, how far in order to the due performance of a given function in any case it is impossible that the organs performing that function should be different from what we find them to be, is quite another question. Thus the teeth of a lion and the stomach of the animal are in such relation that the one is fitted to digest the food which the others can tear; they are physiologically correlated, but we have no reason for affirming this to be a necessary physiological correlation, in the sense that no other could equally fit its possessor for living on recent flesh. The number and form of the teeth might have been quite different from that which we know it to be, and the construction of the stomach might have been greatly altered, and yet the function of these organs might have been equally well performed. Nothing can be more uniform than the physiological ends which have to be attained by living beings; nothing more various than the modes in which they are attained; and it would, I think, in the face of these well-known facts, be the height of presumption to affirm that the function which we see in any case performed in a particular way could not possibly have been performed in any other mode.

If physiological correlations are however not necessary, if, so far as physiology is concerned, we have no right to say with Cuvier, that "Every organized being constitutes a whole, a single, and complete system, whose parts mutually correspond and concur by their reciprocal reaction to the same definite end. None of these parts can be changed without affecting the others, and consequently each taken separately indicates and gives all the rest;"–then a very important consequence follows, viz., that it is quite impossible to reason conclu[434]sively on physiological grounds alone from any part of a living being to the whole.

I by no means assert that Cuvier, in enunciating the proposition quoted above, meant to exclude all but physiological considerations so completely as the words appear to indicate. On the contrary, his practice, no less than other passages of the remarkable essay from which that citation is taken, shows clearly that no man more fully understood the value of morphology. Nevertheless the words of the proposition are distinct enough to justify those who, guided more by authority than by right reason, have denominated it Cuvier's law of correlation, and, ambiguously supported by Cuvier's phraseology elsewhere, have imagined the principle which it involves to have been his guide in palæontological research.

A simple illustration or two, however, will show that the laws of physiological correlation alone are wholly incompetent to furnish such guidance. Suppose I find the jaw of a vertebrate animal with sharp cutting teeth imbedded in it, how far will physiology help me to determine the precise nature of the animal to which it belonged? The sharpness of the teeth may lead me to guess that they were used for cutting some soft substance. The shape of the articular condyle and that of the processes for muscular attachment may equally render probable the direction and force of its ordinary movements; but as to the rest of the organism, whether the teeth were for cutting up fish, flesh, fowl, or carrion, whether the creature itself was piscine or reptilian or mammalian,–on all these points no amount of mere physiological reasoning will help me. Nay, how do I know it is a vertebrate jaw at all; that it is a vertebrate bone and tooth substance? For anything physiology teaches me to the contrary, Invertebrate animals might develope osseous and dentinal tissue, and might possess appendages having the form of vertebrate jaws.

Every naturalist knows that Invertebrate animals do not thus mimic the Vertebrata, and he believes that they never have and never will do so; but his confidence is based, not on any physiological reasoning as to the impossibility of such a proceeding, but on his simple experience that it never does occur. He rests not on a deduction from the laws of physiological correlation, but on the morphological law that no Invertebrate animal ever possesses an organ having the form and structure displayed by the jaw in question. And this law is an empirical one; no further reason for it can be given than for the law of gravitation. The whole object of morphology is to ascertain what structural peculiarities invariably coexist with one another: why these structural peculiarities coexist is a question with which it does [435] not necessarily concern itself, and so far as the mere restorations of the palæontologist are concerned, it is a wholly irrelevant question. The empirical laws of morphology supply all that the palæontologist requires for this object.

Let us imagine that all existing animals had perished, but that their dead forms were gathered together and submitted to the investigation of some intelligent being from whom the knowledge that they had ever lived was concealed. He would of course remain entirely ignorant of physiology and all its laws. Life, if he were acquainted before only with physical and chemical phænomena, would be an inconceivability, and the conception of adaptation to purpose, of physiological correlation, would fail to suggest itself where nothing was known of actions or functions.

Nevertheless, by the careful comparison of one form with another, he would see that in one set of specimens certain structural peculiarities were invariably associated, in another set others, and he would thus arrive at precisely the same laws of morphological correlation,¹ and at the same classification of these dead forms as that which we have reached from our study of the living ones. He would not term Lions and Tigers and Wolves "Carnivora," for he would not even know that they eat anything, but he would assuredly form a group with pretty nearly the same limits as the Carnivora, simply because all these animals resemble one another, and differ from the rest in certain peculiarities of dentition, &c. So, again, he would group Oxen and Sheep and Deer together, because they present corresponding coexistences of structure, though, knowing nothing of their digestive processes, he would not call them "Ruminantia."

And now, after our imaginary being had made himself acquainted with the whole series of forms before him, and had established his great laws of morphological correlation and his classification, suppose that a mass of fragments of other creatures, more or less similar to those which he had first familiarized himself with, were placed before him, and he were desired to put these fragments together, and to reconstruct these dismembered forms, how would he proceed? Suppose the first bone which came to hand very closely resembled the jaw of a Deer, would he not naturally conclude–could he logically escape the conclusion–that in all probability the skull and limbs which belonged to this jaw were like those of a Deer also? And finally, supposing that, guided by this strong probability, he had selected a complete deer skeleton from the mass, all of whose parts [436] were in such proportion to one another and to the jaw first discovered as to accord perfectly with his already ascertained laws of correlation of form in the Deer species, could the validity of his restoration be questioned, because he knew nothing about the purposes of all these parts or their physiological correlation?

What additional certainty would he gain by now learning that the Deer had once lived–that it was herbivorous–that its teeth and internal organs were all exquisitely adjusted to its mode of life? He would say, That is all very beautiful, and I am very glad to know it; but such considerations did not in the least help me to pick out the bones which belonged to the jaw, nor do they add a grain of certainty to that which I already feel as to the justice of my restoration. Indeed, my method tells me a great deal that yours is quite silent about. I knew empirically that the kind of tooth and jaw placed before me was always associated with horns, with slender limbs, and with cleft hooves; but I could never have divined these things from knowing that the jaw and tooth were specially adapted to a herbivorous diet.

Surely all this is so obvious as to need no great amount of demonstration, and no less clear is its application to the question, What is the method of palæontology? How is it that we are able to restore an extinct animal from some fragments of its skeleton? It is by deduction from those empirical laws of morphology which express the invariable coexistences of structures, so far as observation has yet made them known to us, and it is by this method only. When once the general nature of an extinct animal has been ascertained, the laws of physiology may help us to very useful hints and guesses; but the fundamental step towards the determination of the nature of any unknown fragment, whether recent or fossil, are purely morphological, and, so far as they are concerned, physiology might be non-existent.

The truth of what has just been asserted must long have been familiar to every thinking botanical palæontologist; and I have never met with any indication, either in their works or in conversation that the botanists imagined they were guided in their determinations of extinct plants by any reference to physiological correlation, or by any other method than deduction from purely empirical morphological laws. Nor does the palæontologist, who concerns himself with invertebrate forms, often seek for help from physiology. In fact, the total absence of any acquaintance with physiology which many excellent palæontologists manifest, is a curious illustration of the justice of my line of argument, as it nowise interferes with the [437] soundness of their work,–so long as they confine themselves to such purely morphological questions as are involved in the restoration of extinct forms.

Nor can I find that in practice those palæontologists who have studied the Vertebrata trouble themselves much about physiological correlations or adaptations to purpose. The reader of Cuvier's "Ossemens fossiles" might begin at the tenth volume and read on to the second, and while he would be astounded at the enormous knowledge of the laws of morphology–of the observed coexistence of parts which it displays–he would find himself very rarely troubled with any remarks upon physiological correlations or adaptations; and any which might offer themselves would be entirely subordinate to the great object of the work, which is, to apply the purely empirical laws of morphological correlation, which have been ascertained to obtain among living beings, to the elucidation of fossil remains.

It is with no little surprise, therefore, that in the first volume he finds, or seems to find, the principle of physiological correlation brought prominently forward, in the celebrated 'Discours sur les Révolutions,' as the guide in palæontology, as the especial means by which the determination of mammalian fossils, at any rate, is effected. I say, seems to find; for, after all, if the master's words be studied carefully, it will be discovered that his followers are more Cuvierian than Cuvier.

In fact, as I have already particularly pointed out, in a lecture which I recently delivered before the members of the Royal Institution, Cuvier gives up the principle of physiological correlation, both explicitly in words and implicitly in practice, as an exclusive guide in palæontological research; and he expressly admits the necessity of a reference to the laws of morphological correlation.

But while admitting the importance of both methods, the physiological and the morphological, he gives to the former by his words a prominence which it by no means has in his practice; or perhaps I may more justly say, that his phraseology is ambiguous, from his having confounded the two methods together, under the one term of "principe de la corrélation des formes dans les êtres organisés." Those who will read carefully from p. 178 to p. 189 (ed. 4, 1834) of the 'Discours,' will find that this confusion exists throughout. Thus, if we take one of the opening passages already cited (p. 178):–

The first paragraph here embodies the principles of both physiological and morphological correlation. The second paragraph, however, regards physiological correlation only, and the statement which it contains is not true. We have no evidence to justify us in asserting that no one part can be changed without affecting all the others. On the contrary, we have abundant evidence to show that allied species, for instance, differ in only a single character; which would be an impossibility if a change in one part sensibly affected all the rest.

Cuvier then goes on to show, in a very beautiful manner, the physiological correlation which exists between the parts of a Carnivore, concluding with the well-known phrase, "in the same way the claw, the scapula, the condyle, the femur, and all the other bones taken separately, will give the tooth, or one another; and by commencing with any one, he who had a rational conception of the laws of the organic œconomy could reconstruct the whole animal."

If Cuvier means by "the laws of the organic œconomy," (and the context would indicate that he does), its physiological laws merely, then I must venture to say, that I believe this assertion to be incorrect. I do not believe that the problem–given a tooth or a bone, the mode of life of an animal, and the laws of physiology, to find the structure of other parts of the body of that animal,–is a soluble one.

In fact, Cuvier himself, in the very next paragraph (p. 182), almost gives up his own principle. I give his own words:–

And again, in concluding, at p. 187 Cuvier says:–

Finally, at page 184, after speaking of those invariably coexistent [439] peculiarities of organization among the Ruminants, which have no apparent physiological connexion, Cuvier says:–

I confess that, considering the Pig has a cloven foot, and does not ruminate, the last assertion appears to me to be a little strong. But my object is not to criticise Cuvier, but simply to show that nothing could be more marked than his appreciation of the value of the merely empirical laws of morphology, as applied to palæontology, nothing more erroneous than the popular notion, too much favoured by his own language, that his method essentially consisted in reasoning from supposed physiological necessities. In the lecture above referred to, I not only maintained this view, but I further asserted, and endeavoured to prove, that not only are popular and other writers thus mistaken in interpreting Cuvier, but that Cuvier himself was in error in ascribing to the laws of physiological correlation that primary importance in palæontology which he undoubtedly does give them. I brought forward, in fact, the doctrine which I have argued at greater length in the preceding pages, viz. that palæontology, so far as it consists in the restoration of extinct forms, is entirely based upon deductions from the empirical laws of morphology; that its conclusions, so far, would be as valid if the whole science of physiology were non-extant, and if we knew nothing of final causes or adaptations to purposes.

The publication of the abstract of the lecture has elicited a brusque attack from Dr. Falconer, which, coming as it did from the pen of a palæontologist of high repute, caused me at first, I must confess, no slight alarm; the more so as Dr. Falconer, in his laudable desire at once to extinguish heresy, had, I found, taken the somewhat unusual course of widely circulating his little pamphlet.

The perusal of Dr. Falconer's essay, however, soon relieved me from my only real source of uneasiness, by demonstrating very clearly that Dr. Falconer had been far too much in a hurry either to master the real question in dispute, to read what I had written with atten[440]tion, or to quote me with common accuracy and fairness. In fact, I have not the good fortune to be among the "tantis viris" de quibus "modeste tamen et circumspecto judicio pronuntiandum est," and it is clearly in Dr. Falconer's opinion not worth while to use much circumspection in dealing with the opinions of mere ordinary "viri."

The first evidence of Dr. Falconer's entire misconception of the point at issue meets one in the title-page–"On Prof. Huxley's attempted refutation of Cuvier's Laws of Correlation in the reconstruction of extinct Vertebrate Forms." It is repeated at page 477. "Nearly three-fourths of Mr. Huxley's abstract are devoted to the first head, viz., Natural History, regarded as knowledge, the leading feature of which is an attempt to refute the principle propounded by Cuvier, that the laws of correlation which preside over the organization of animals, guided him in his reconstruction of extinct Forms." Nothing can be more entirely incorrect than the assertion contained in the latter part of this paragraph. I did not attempt to refute any one of Cuvier's laws of correlation. There is not a passage in my lecture which can be justly so interpreted. I merely endeavoured to prove, and I can find nothing in Dr. Falconer's essay to show that I did not prove, first, that the physiological laws of correlation which Cuvier laid down are not as universally and necessarily applicable as he seems to have imagined; secondly, that his physiological laws of correlation are of wholly subordinate importance in palæontology, if not absolutely unimportant, the really important laws by which he worked being those morphological laws, those empirical laws of coexistence which, as I have said, no man lays down more clearly, but to which he nevertheless ascribes in words, though not in practice, a subordinate place. This entire misunderstanding of the real point under discussion vitiates the whole of Dr. Falconer's paper. It is again repeated at p. 481, just after Dr. Falconer has gravely warned us how necessary are "precision of thought and expression in disquisitions of this kind."

So again, at p. 487, Dr. Falconer says:–

I assert that no one who carefully reads my abstract will find the slightest ground for the assertion that I have ever made use of any such argument as that imputed to me by Dr. Falconer. What I say in regard to plants is:–

To any unprejudiced reader of ordinary intelligence it will be quite obvious that the question of the existence of physiological correlation between the parts of plants is here utterly untouched. The question is whether the physiological or the morphological laws of correlation guide the botanical palæontologist. I affirm the latter and I am supported by every botanist with whom I have spoken on the subject.

Dr. Falconer writes at p. 487:–

Now what is this but an admission of all that I have contended for, namely, that the physiological correlation of organs is wholly subordinate to their morphological or, in other words, typical correlation? What is it that Dr. Falconer attacks, after all? And this question becomes all the more bewildering, when we find at p. 480:

Surely Dr. Falconer can understand that adaptation to purpose is adaptation to use, and that therefore adaptation to purpose may well be said to be 'utilitarian.'

In answer to the next part of his inquiry, I must refer him to Dr. Whewell;² and with regard to the last part, the misuse of words is Dr. Falconer's. I am not speaking of any inference from the principle, but of the principle itself.

But the most curious proof that Dr. Falconer has not taken the trouble to read with attention or think over carefully the statements contained in my abstract is yielded by the passage at p. 480, begin[442] ning, "Mr. Huxley contrasts the two as opposite dogmas." Dr. Falconer here takes two parts of the same argument, thrusts them into opposition, and is then excessively puzzled to discover that he can find no "opposition or incompatibility" between them. However glad I may be to have Dr. Falconer's testimony to the connexion of the two parts of my argument, even malgré lui, I think he would have done well to have read the passage twice before entangling himself in it.

Dr. Falconer writes at p. 490:–

This is in the teeth of the passage of my abstract, which Dr. Falconer himself quotes at p. 487: "And if it were necessary to appeal to any authority save facts and reason, our first witness would be Cuvier himself, who in a very remarkable passage, two or three pages further on ('Discours,' pp. 184, 185), implicitly surrenders his own principle." Surely this amount of careless incorrectness is hardly venial. Surely I may quote to Dr. Falconer his own courteous words, "rarely in the history of science has confident assertion been put forward in so grave a case upon a more erroneous and unsubstantial foundation."

Just after reproaching me at p. 482, as I conceive unjustifiably, with affirming a case to be one of Cuvier's selection, which is not so, Dr. Falconer falls into the precise error which he wrongfully attributes to me.

What I say is, "If Bears were only known to us in the fossil state." Dr. Falconer's proviso, in fact, is the precise nullification of my argument, and yet he still ventures to quote it as mine. So again at p. 483, after discussing the Bear question, Dr. Falconer states, "Mr. Huxley next takes in hand the opposite case of the Ungulate Herbivora, as put by Cuvier." Dr. Falconer's assertion is inaccurate; I do not next take in hand the Ungulate Herbivora; any one who will read my abstract may see that the discussion as to the Bears comes [443] at the end of the argument about the Ungulata, forming not a separate question or opposite case, but part of the same.

But here as elsewhere, Dr. Falconer seems to forget the important distinction between a question of detail and one of principle. If physiological arguments are good at all in the way Cuvier put them, they must be universal in their application, in which case any exception is fatal; on the other hand, if they be of limited application, before we can apply them in palæontology, we must first have ascertained to what group the subject of our studies belongs by other means, and these can only be the application of morphological laws.

I trust I have now brought forward sufficient evidence to justify my accusation of misrepresentation and misconception on Dr. Falconer's part, and I would most willingly leave the subject, were it not necessary in defence of myself and others to advert to one or two other points in Dr. Falconer's attack. In two of these, accuracy as to matters of fact is involved. The first relates to the Stonesfield Mammal, a title which has been applied as much to the Phascolotherium as to the Amphitherium. Dr. Falconer asserts, that I have been unhappy in my citation of this case, because the Amphitherium is an Insectivore, and because the Phascolotherium has fewer teeth than the Amphitherium. Candour might have led Dr. Falconer to quote a little more of Prof. Owen's opinion as to the latter animal than he does.³ If he had combined careful thought with candour, he would have perceived that inasmuch as the Phascolotherium possesses forty-eight teeth (four more than the typical number in Mammals), and has the strongly inflexed angular process, it precisely fulfils the conditions of my argument. In point of fact, however, the number of teeth is an irrelevant consideration. The other question of fact relates to the structure of the Sloth's tooth; when Cuvier speaks of the alternation of substance in the teeth of an Ungulate animal, he obviously refers to that peculiar alternation of vertical plates of enamel, dentine and cement, which the teeth of the typical Ungulates present. A difference of structure in layers parallel to the crown of the tooth, is of course possessed by every Carnivore, and it is this kind of arrangement which the Sloth also presents. I venture to think, therefore, that this objection to my argument is like most of Dr. Falconer's, and to use his own words, "more specious than valid."

[444] I have left untouched many points in Dr. Falconer's essay, not because they cannot be answered, but because I conceive they will answer themselves. Under this category I leave such passages as those at p. 488, the singular bad taste of which will cause Dr. Falconer in his cooler moments, far more annoyance than they have occasioned to any one else, except his friends. But I cannot pass without more grave comment, the allusion, at p. 477, to the audience which I had the honour to address. Dr. Falconer's apparent ignorance of the nature of the Friday evening audience at the Royal Institution–one which the best men in this country approach gravely and earnestly knowing as they do that, whatever be the "mixture" of their hearers, there is pretty sure to be among them a fair jury of their peers, can be his sole excuse for the tone of his remarks.

^l Except so far as he would be deprived of the advantage of the study of development. This, however, obviously by no means interferes with the validity of the general argument.

PREVIEW TABLE of CONTENTS BIBLIOGRAPHIES 1.   THH Publications 2.   Victorian Commentary 3.   20th Century Commentary INDICES 1.   Letter Index 2.   Illustration Index TIMELINE FAMILY TREE Gratitude and Permissions C. Blinderman & D. Joyce Clark University 1998

THE HUXLEY FILE

GUIDES § 1. THH: His Mark § 2. Voyage of the Rattlesnake § 3. A Sort of Firm § 4. Darwin's Bulldog § 5. Hidden Bond: Evolution § 6. Frankensteinosaurus § 7. Bobbing Angels: Human Evolution § 8. Matter of Life: Protoplasm § 9. Medusa § 10. Liberal Education § 11. Scientific Education § 12. Unity in Diversity § 13. Agnosticism § 14. New Reformation § 15. Verbal Delusions: The Bible § 16. Miltonic Hypothesis: Genesis § 17. Extremely Wonderful Events: Resurrection and Demons § 18. Emancipation: Gender and Race § 19. Aryans et al.: Ethnology § 20. The Good of Mankind § 21.  Jungle Versus Garden