[658] THE attempt to form a just conception of the value of work done in any department of human knowledge, and of its significance as an indication of the intellectual and moral qualities of which it was the product, is an undertaking which must always be beset with difficulties, and may easily end in making the limitations of the appraiser more obvious than the true worth of that which he appraises. For the judgment of a contemporary is liable to be obscured by intellectual incompatibilities and warped by personal antagonisms; while the critic of a later generation, though he may escape the influence of these sources of error, is often ignorant or forgetful of, the conditions under which the labours of his predecessors have been carried on. He is prone to lose sight of the fact that without their clearing of the ground and rough-hewing of the foundation-stones, the stately edifice of later builders could not have been erected.

In view of these considerations, it was not altogether with a light heart that I assented to the proposal Sir Richard Owen's biographer did me the honour to make, that I should furnish him with a critical estimate of the extensive and varied labours in the field of natural science carried on, for some sixty years, with singular energy, by that eminent man. For I have to reckon, more than most, with those causes of imperfect or distorted vision to which, as I have said, the eyes of contemporaries are obnoxious; and, however confident of the will to correct their effects, I can hardly hope to be entirely successful, without more good fortune than I have a right to look for.

[659] It is an enhancement of the difficulties of the task set me, that what I have to say must be addressed not to experts, but to the general public, to the great majority of whom anatomy is as much a sealed book as the higher mathematics. Even if some few have penetrated a little way, their progress has probably been arrested by the discovery that discussions about anatomical topics are, as a rule, pre-eminently dry and technical. It must be admitted that there is some justification for the popular distaste for anatomical science. The associations of the subject are not wholly pleasing; and, undoubtedly, a long and weary process of initiation is indispensable to the neophyte, who aspires to become an adept and to feel at home in the arcana of the higher anatomy. But I think it ought to be possible to lead any one, who will give a reasonable amount of attention, to a point, from which he may obtain a sufficiently accurate general view of the scope of anatomical science, by a shorter and easier road. In any case, it is laid upon me to attempt to show the way there, inasmuch as the purport of much of Sir Richard Owen's work cannot be understood, nor can his position in science be properly appreciated, unless such a point of view is attained. And in proffering such guide's service it may be well to remind those who accept the offer, that in this, as in so many other cases, 'the longest way round is the shortest way home; there is nothing for it but to follow the path of history and eschew short cuts, however tempting they may be.

Etymologically, the word 'Anatomy' signifies no more than 'cutting up,' or 'dissection;' but, in course of time, the idea of the chief means by which the structure of animals and of plants was ascertained merged with that of the results it yielded. And since structure, or inward form, is practically inseparable from shape, or outward form, the latter also fell within the range of the anatomist. Further, it was natural enough that the 'function' or use of the parts, the inward and outward form of which they described, should also be treated of by the early and mediæval anatomists; but, as the subject grew, division of labour not only became practically necessary, but was theoretically indicated by the diverse characters of its moieties. Form can be considered without any reference to function; and function can be studied with very little reference to form. One need know nothing of the structure of the eye, for example, to make sure that it is the organ of vision; and a minimum of anatomical lore suffices to establish the familiar truths that the stomach is largely concerned in digestion, and the lungs in respiration. Moreover, the [660] preliminary training required for the effectual prosecution and advancement of the several studies of form and of function is so different, that, in modern times, the two have steadily tended to fall into different hands. The doctrine of form, whether in the shape of anatomy, histology, embryology, taxonomy (that is, systematic arrangement), or distribution, has become the business of the 'morphologist,' to whom it is a matter of no essential importance whether the subjects of his inquiries are alive or have been dead for millions of years. On the other hand, since functions are the modes of manifestation of the activities of living matter in ultimate resort they must he studied in living beings. The exact forms which the mechanisms of the functions may assume is a matter of subordinate interest. By a curious and somewhat unfortunate chance, the name of 'physiologist,' originally applied to those primal philosophers of ancient Greece who took all Nature for their province, has been inherited by the investigators of function, to whom it has no more special application than to any other students of Nature.

Arrived at the parting of the ways¹ the one of which leads to the province of physiology, the other to that of morphology, we must take the latter. It is no disparagement to Owen to say that he was not a physiologist in the modern sense of the term. In fact, he had done a large part of his work before modern physiology, in which no progress can be made without clear mechanical, physical, and chemical conceptions, came into existence; and I think it may be doubted whether he ever became fully aware of the vastness of the interval which separates the physiology of John Hunter from the physiology of Johannes Müller and his successors.

Morphology has grown out of anatomy; and anatomy, like most branches of science, if not begotten and born amongst the ancient Greeks, was nurtured and brought up in the way it should go by them. Aristotle, with his immediate predecessors and successors, took the broadest possible view of the subject; the structure of cuttlefishes and crayfishes interested them as much as that of the higher animals. And inasmuch as the taint of impurity which, in ancient times attached to contact with the dead human body, hindered them from obtaining a knowledge of the structure of man directly, they were compelled to divine it, by way of analogy, from their observations on [661] apes, In fact, their over-confidence in the extent to which the likeness extended led them into serious errors. At the revival of learning, things took another turn. Anatomy sank to the level of a mere handmaid to practical and theoretical medicine. It was only very much later, as the anatomical, like other pure sciences, progressed backwards to their original dignity and independence, that the position of Democritus and of Aristotle was once more reached; and, the study of the living world being taken up for the sake of knowledge alone, man assumed his place as neither more nor less scientifically interesting than his fellows. In the sixteenth and seventeenth centuries, however, the great anatomists of the Low Countries and of Italy had pushed their investigations so far, that more was known of the structure of man than of that of any other animal. It was therefore natural, and indeed unavoidable, that the structure of man should become the standard of comparison, or, in other words, the 'type' to which all other kinds of animal structure were to be referred. The organs of animals were interpreted by the analogy of those of man; the terminology of human structure was extended to the structure of animals in general.

Thus the anatomy of the whole of the rest of the animal world came to be regarded as a sort of annexe of human anatomy; it acquired the name of 'comparative anatomy,' and the conception of the relations of man to the rest of the living world was completely falsified. Man, regarded merely as an animal, was held to be the most perfect of all the works of Nature, below which all the rest could be arranged in a graduated series of forms to the lowest animals; from thence, the descending steps were traced through the vegetable world to the lowest plants; and through the definitely formed to the apparently indefinite mineral constituents of the globe. Hence arose the conception of une échelle des étres, a ladder between stones and men, the rungs of which are the species or kinds of living things.

But gradation implies a certain community between the grades. Degrees of colour are shades of the same colour, or mixtures in which the same colours exist in varying proportions; gradations of form imply similarities of form between the successive steps of the gradation. Thus the idea of a scale of organised beings foreshadows the conception of a more or less widely prevailing unity of organisation among them, and we may regard the promulgation and wide acceptances of Bonnet's doctrine of the 'scale of beings' as the dawn of the higher morphology of modern times.

Though but an imperfect apprehension of a great truth, this [662] doctrine exerted a highly beneficial influence upon the progress of comparative anatomy. The gradations in structure of the parts and organs of animals were carefully studied. Immense pains were bestowed on the formation of collections of preparations illustrative of gradation; and there is no more remarkable example of such a collection than that formed by the skill and industry of John Hunter, which was the origin, and still constitutes the nucleus, of the present admirably complete museum of the Royal College of Surgeons of England. A full descriptive catalogue of such a collection must needs be, in itself, an encyclopædia of comparative anatomy. Daubenton, the collaborator of Buffon in France, went to work upon a different, but quite as important, principle. As Buffon opposed the extreme systematizers, who seemed to think it the end of science, not so much to know about an object as to be able to name it and fit it into their system, so Daubenton insisted on the study of each animal as an individual whole. Zoologists who knew and could properly apply every technical term of the systema naturæ without the least real acquaintance with animal structure in general, or with that of any single animal in particular, were not to his mind. He occupied himself, therefore, with the production of a series of admirable monographs appended to. the descriptions of Buffon in the 'Histoire Naturelle.'²

The effect of the co-operation of many zealous workers, along the first of these lines, culminated in the 'Anatomie Comparé' of Cuvier; while, to the followers of the second method, we owe a host of monographs upon species, or groups of species, belonging to all the divisions of the animal kingdom. In virtue of these labours it came about that, by the year 1830, the province of anatomy had been systematically, and, in many regions, minutely, surveyed. An adequate, though far from complete, knowledge of all the higher forms had been attained; and, with the improvement of the microscope, the structural characters of the very lowest forms were beginning to be elucidated.

Thus, the foundations of anatomical science in accurately recorded observations of structure were solidly and securely laid sixty years ago. In fact, the importance of the work done by that time cannot be over-estimated; for, as Cuvier has somewhere said, whatever may become of hypotheses, the man who has made a permanent addition [663] to our knowledge of facts, has rendered an imperishable service to science. Nevertheless, it is an equally profound truth, of which no one was more conscious than Cuvier himself, that the ascertainment of facts, in the narrowest sense of the word, and the methodical recording of such facts, though it is the beginning of scientific righteousness, is only the beginning. To reach the end, that which is common to groups of details must be carefully sifted out and expressed in general propositions; and these, again, must be tentatively colligated by the guarded and restrained play of the imagination, in the invention of hypotheses, susceptible of verification or negation by. further observation.

The vulgar antithesis of fact and theory is founded on a misconception of the nature of scientific theory, which is, or ought to be, no more than the expression of fact in a general form. Whatever goes beyond such expression is hypothesis;. and hypotheses are not ends, but means. They should be regarded as instruments by which new lines of inquiry are indicated; or by the aid of which a provisional coherency and intelligibility may be given to seemingly disconnected groups of phenomena. The most useful of servants to the man of science, they are the worst of masters. And when the establishment of the hypothesis becomes the end, and fact is alluded to only so far as it suits the 'Idée,' science has no longer anything to do with the business.

The nature of plants and animals, on the one hand, and of the human mind on the other, is such that the process of generalisation and that of classification, which is the correlative of generalisation, take place instinctively and find expression in common language. The terms 'beasts,' 'birds,' 'fishes,' are the names of certain groups of animals in the popular classification; and, though the user of them may not be able to put his thoughts into words, they imply that he has perceived that the things he calls by these several names have certain common and distinctive characters. And that perception, when it is put into words, is a generalisation, which, in so far as it is accurate, also expresses an empirical 'law of Nature.'

The classifications of the scientific taxonomist are of two kinds. Those of the one sort are merely handy reference catalogues. Such are the 'artificial' systems, useful in their day and for their particular purpose, but of no other value. The others, known as 'natural' classifications, are arrangements of objects according to the sum of their likenesses and unlikenesses, in respect of certain characters; in morphology, therefore, such classifications must have regard only to matters of form, external and internal. And natural classification is [664] of perennial importance, because the construction of it is the same thing as the accurate generalisation of the facts of form, or the establishment of the empirical laws of the correlation of structure.

To say that deer, oxen, sheep, goats, antelopes, and so on, form a natural group, definable by the co-existence in them of certain forms of bones, teeth, stomach, and the like, which are not co-existent in any oilier group, is one way of stating certain facts. It is merely another, if we say that it is an empirical law of existing Nature that such and such structures are always, found together; and that when we meet with one, there is a primal facie ground for suspecting that the others are associated with it. The finder of a recent skull, provided with a pair of horn-cores, in which the front part of the upper jaw is toothless, may thus safely predict that the animal to which it belonged possessed paired hoofs and a complex stomach though no amount of merely physiological lore would enable him to so much as to guess why the one set of characters is thus constantly associated with the other. The key of the enigma, in fact, does not lie in the hand of the physiologist, but in that of the historian of animal life throughout the ages of its existence.

In the middle of the eighteenth century, the value of the artificial systems invented by Linnæus, as a part of his method of introducing order into the chaos of 'Natural History,' was so much felt, that his clear recognition of their essentially provisional character was ignored by the host of disciples; who, as usual, appreciated most highly, and were most sedulous to imitate, the weakest parts of their master's teachings. The genius of Buffon strove against this tendency to substitute empty schematisms for science almost in vain. Botany became a cataloguing of 'hay;' and zoology, of skins and shells; indeed, of straw, if 1 may revive a jest of my old friend Edward Forbes–not without serious application even in his time–to the effect that the pure systematic zoologist was unaware that the stuffed skins he named and arranged ever had contained anything but straw.

Before long, however, better days began to dawn; and the light came partly from the purely scientific anatomists, partly from men of more or less anatomical knowledge, in whom the artistic habit of visualising ideas was superadded to that capacity for exact observation which is the foundation of both art and science.

Scientific observation tells us that living birds form a group or class of animals, through which a certain form of skeleton runs; and that this kind of skeleton differs in certain well-defined characters from that of mammals. On the other hand, if any one utterly ignorant of osteology, but endowed with the artistic sense of form, were [665] set before a bird skeleton and a mammalian skeleton, lie would at once see that the two were similar and yet different. Very likely he would be unable to give clear expression to his just sense of the differences and resemblances; perhaps he would make great mistakes in detail if he tried. Nevertheless, he would be able to draw from memory a couple of sketches, in which all the salient points of likeness and unlikeness would be reproduced with sufficient accuracy. The mere osteologist, however accurately he might put the resemblances and differences into words, if he lacked the artistic visualising faculty, might be hopelessly incompetent to perform any such feat; lost in details, it might not even occur to him that it was possible; or, still more probably, the habit of looking for differences might impair the perception of resemblances.

Under these circumstances, the artist might be led to higher and broader views, and thus be more useful to the progress of science than the osteological expert. Not that the former attains the higher truth by a different method; for the way of' reaching truth is one and indivisible. Whether he knows it or not, the artist has made a generalisation from two sets of facts, which is perfectly scientific in form; and trustworthy so far as it rests upon the direct perception of similarities and dissimilarities. The only peculiarity of the artistic application of scientific method lies in the artist's power of visualising the result of his mental processes, of embodying the facts of resemblance in a visible 'type,' and of showing the manner in which the differences may be represented as modifications of that type; he does, in fact, instinctively, what an architect, who desires to demonstrate the community of general plan in certain ancient temples, does by the methodical construction of plans, sections and elevations, the comparison of which will furnish him with the 'type' of such temples.

Thus, what I may term the artistic fashion of dealing with anatomy is not only perfectly legitimate, but has been of great utility. The harm of it does not begin until the attempt is made to get more out of this visual projection of thought than it contains; until the origin of the notion of 'type' is forgotten and the speculative philosopher deludes himself with the supposition that the generalisation suggested by fact is an 'Idea' of the Pure Reason, with which fact must, somehow or other, be made to agree.

The old French naturalist Belon, who must have been a good deal of an artist, and illustrated his book, 'L'Histoire de la Nature des Oyseaux,' with many 'naifs portraicts,' initiated this way of dealing with anatomy. The skeleton of a bird is set beside that of a man [666] and the reader is left to draw the obvious conclusion. as to their 'unity of organisation.' A child may see that skull 'answers' to skull; spinal column to spinal column; ribs to ribs; breast bone to breast bone; wings to arms; and legs to legs, in the two. Later on, Peter Camper, a capital artist as well as an accomplished anatomist, was in the habit of amusing, while he instructed, his class by showing what slight strokes of his chalk sufficed to turn the outline skeleton of a man into that of a dog or of an ox ; and how these could be metamorphosed into, reptilian or fish forms, without disturbance of their fundamental features.

The cultivator of botany, who went beyond the classification of 'hay,' became familiar with facts of the same order. Indeed, flowering plants fairly thrust morphological ideas upon the observer. Flowers are the primers of the morphologist ; those who run may read in them uniformity of type amidst endless diversity, singleness of plan with complex multiplicity of detail. As a musician might say, every natural group of flowering plants is a sort of visible fugue, wandering about a central theme which is never forsaken, however it may momentarily, cease to be apparent.

Vicq d'Azyr, following the line of strict anatomical observation and critical comparison, set forth the correspondences of plan observable in the limbs of the higher vertebrates, and may be considered the founder of the purely scientific higher anatomy.

A few years later, art again took the lead in the person of Goethe. Like all the really great men of literature, Goethe added some of the qualities of the man of science to those of the artist, especially the habit of careful and patient observation of Nature. The great poet was no mere book-learned speculator. His acquaintance with mineralogy, geology, botany, and osteology, the fruit of long and wide studies, would have sufficed to satisfy the requirements of a professoriate in those days, if only. he could have pleaded ignorance of everything else. Unfortunately for Goethe's credit with his scientific contemporaries; and, consequently, for the attention attracted by his work, he did not come forward as a man of science until the public had ranged him among the men of literature. And when the little men have thus classified a big man, they consider that the last word has been said about him; it appears to be thought hardly decent on his part if he venture to stray beyond the speciality they have assigned to him. It does not seem to occur to them that a clear intellect is an engine capable of supplying power to all sorts of mental factories; nor to admit that, as Goethe somewhere pathetically remarks, a man may have a right to live for himself as well as for the [667] public; to follow the line of work that happens to interest him, rather than that which interests them.

On the face of the matter, it is not obvious that the brilliant poet had less chance of doing good service in natural science than the dullest of dissectors and nomenclators. Indeed, as I have endeavoured to indicate, there was considerable reason, a hundred years ago, for thinking that an infusion of the artistic way of looking at things might tend to revivify the somewhat mummified body of technical zoology and botany. Great ideas were floating about; the artistic apprehension was needed to give these airy nothings a local habitation and a name; to convert vague suppositions into definite hypotheses. And 1 apprehend that it was just this service which Goethe rendered by writing his essays on the intermaxillary bone, on osteology generally, and on the metamorphoses of plants.³

I do not think that any one who studies these works, in many ways so remarkable, can doubt that, in the last two decades of the eighteenth century, Goethe arrived, by a generally just, though by no means critical, process of induction, at the leading theses of what were subsequently known as Naturphilosophie in Germany, and as Philosophie anatomique in France; in other words, that he was the first person to enunciate and conceive as parts of a systematic whole, whatever principles of value are to be met with in the works of Oken, Geoffroy, and Lamarck.

Of the idea of 'unity of organisation' which is fundamental for all three, Geoffroy St. Hilaire himself, writing in 1831, says:

Furthermore, the notions of a necessary correlation between excess of development in one direction and diminution in another; of the natural evolution of the animal and vegetable worlds from a common foundation; of the direct influence of varying conditions on the process of evolution, are all to be found, indeed are plainly enunciated, in Goethe's writings. In addition, he sometimes uses [668] language which may be fairly interpreted as an anticipation of the fundamental teachings of modern histology and embryology; a fact which is by no means wonderful, when we consider that Goethe was well acquainted with Caspar F. Wolff and his writings.

All this is mere justice to Goethe; but, as it is the unpleasant duty of the historian to do justice upon, as well as to, great men, it behoves me to add that the germs, and more than the germs, of the worst faults of later speculative morphologists are no less visible in his writings than their great merits.⁴ In the artist-philosopher there was, at best, a good deal more artist than philosopher; and when Goethe ventured into the regions which belong to pure science, this excess of a virtue had all the consequences of a vice. 'Trennen und zahlen lag nicht in meiner Natur,'⁵ says lie; but the mental operations of which 'analysis and numeration' are partial expressions are indispensable for every step of progress beyond happy glimpses, even in morphology; while, in physiology and in physics, failure in the most exact performance of these operations involves sheer disaster, as indeed Goethe was afforded abundant opportunity of learning. Yet he never understood the sharp lessons he received, and put down to malice, or prejudice, the ill-reception of his unfortunate attempts to. deal with purely physical problems.

Goethe's contributions to the science of morphology (the very term 'morphology,' in its technical sense, is his) were by no means so widely known to anatomists, or valued by them, as they ought to have been; and it was long before their unquestionable merits were properly appreciated. The most brilliant and, at the same time, the soberest representative of the higher or 'philosophical' anatomy, Geoffroy St. Hilaire, seems, at first, to have known nothing of them. Like Goethe, he had studied mineralogy and botany before taking up anatomy and zoology; an excellent and most industrious observer, he was, at the same time, a man of high intellect and comprehensive views. Intimately associated with young Geoffroy, and only a couple of years older, was Cuvier, one of the most remarkable intelligences of his own or any time. And when these energetic allies turned their attention to vertebrate anatomy, in 1794-5, it was impossible that the facts which had impressed Goethe should fail to lead minds such as theirs towards ideas of the same order. But the minds of the two having a widely different commixture of qualities, the way in which they dealt with the same objective material presented corresponding differences ; and these differences went on widening [669] until, thirty-five years later, these two bosom friends became the antagonists in the most famous of all scientific duels.

However, during the earlier part of his career, I doubt if Cuvier would have categorically denied any of Geoffroy's fundamental theses. And even in his later years, Sir Charles Lyell, many years ago, gave me reasons for the opinion that Cuvier was by no means confident about the fixity of species. There was never any lack of the scientific imagination about the great anatomist; and the charge of indifference to general ideas, sometimes brought against him, is stupidly unjust. But Cuvier was one of those happily endowed persons in whom genius never parts company with common-sense; and whose perception of the importance of sound method is so great that they look at even a truth, hit upon by those who pursue an essentially vicious method, with the sort of feeling with which an honest trader regards the winnings of a gambler. They hold it better to remain poor than obtain riches by the road that, as a rule, leads to ruin.

So far as Cuvier was actuated by such feelings, one can but applaud the course he took. For it is plain to any one, who studies these old controversies by modern lights, that Geoffroy, however good his general ideas may have been, was singularly unfortunate in his attempts to illustrate and enforce them. Even where he was strongest, as upon the topic of !he unity of organisation of the Vertebrates, I do not think there is one of his exemplifications of that unity which has withstood criticism; and, in respect of the primary cause of contention in 1830, the comparison of the vertebrate and the cephalopod types, he was quite hopelessly in the wrong.

To any one possessed of Cuvier's vast knowledge and dialectic skill, therefore, it was rarely difficult to cut the ground from under his opponents' feet; to say, in short, whether you are right or wrong, the evidence you adduce in support of your case, where it is not demonstrably contrary to fact, is inadequate. And, in the main, Cuvier has been justified by the larger knowledge of our day. There is no 'unity of organisation' in the sense maintained by Geoffroy, though there is in another sense. Neither Geoffroy, nor Lamarck, adduced any evidence of the modifiability of species sufficient to overcome the strictly scientific arguments adduced on the other side; and it was not till many years later, that the progress of palæontology justified the hypothesis of progressive modification, which Geoffroy himself, fully admitting the lack of evidence, put forward merely as a suggestion.

In later life, however, Cuvier seems to have become so much disgusted by the vagaries of the Naturphilosophie school, and to have [670] been so strongly impressed by the evil which was accruing to science from their example (let those who are disposed to blame him read Oken's 'Physiophilosophy'), that he was provoked into forsaking his former wise and judicious critical attitude; and, in his turn, he advocated hypotheses, which were none the better than those of his opponents because they happened to be in favour with the multitude, instructed and uninstructed. The doctrines of emboítement in embryology; of periodical geological catastrophes; of the fixity of species; of physiological deduction, as the basis of palæontology; and the restriction of the scope of biological science to mere observation and classification–which is fairly deducible from some of Cuvier's dicta, though I do not believe he ever intended that it should be–are not one whit more scientifically respectable than the least sober speculations of Geoffroy.

The irony of history is nowhere more apparent than in science. Here we see the men, over whose minds the coming events of the world of biology cast their shadows, doing their best to spoil their case in stating it; while the man who represented sound scientific method is doing his best to stay the inevitable progress of thought and bolster up antiquated traditions. The progress of knowledge, during the last seventy years, enables us to see that neither Geoffroy, nor Cuvier, was altogether right, nor altogether wrong; and that they were meant to hunt in couples instead of pulling against one another. Science has need of servants of very various qualifications; of artistic constructors no less than of men of business; of people to design her palaces and of others to see that the materials are sound and well fitted together; of some to spur investigators and of others to keep their heads cool. The only would-be servants, who are entirely unprofitable, are those who do not take the trouble to interrogate Nature, but imagine vain things about her; and spin, from their inner consciousness, webs, as exquisitely symmetrical as those of the most geometrical of spiders, but, alas! as easily torn to pieces by some unconsidered bluebottle of a fact.

Naturally, it is Cuvier, in his capacity of the man of business, who has been held in almost exclusive veneration by those (and they are always the majority) who engage in merely adding to the capital stock of science. For them, he has done everything and is the highest of exemplars. And justly, for Cuvier's monographs, and the osteological treatises interpolated in the 'Ossemens Fossiles,' are of unsurpassed excellence; while, for the sagacious application of the data of osteology to the interpretation of fossil remains, he has never had a superior. Again, Cuvier's clear logical head and marvellously [671] wide acquaintance with animal forms enabled him to reform classification; and to set forth, in the 'Régne Animal,' a generalized statement of the facts of animal structure which was, in itself, a sufficient refutation of the doctrine of unity of organisation as it was conceived by Goethe and Geoffroy. The mere quantity of the palæontological work alone which Cuvier turned out is amazing, and it hardly ever falls below the level of the highest excellence. Moreover, Cuvier incidentally did as great service to the cause of sound morphology as any of the philosophical anatomists. He worked out the principles of the latter as far as they could be safely carried, and showed that their method must needs, in the end, stop short for want of a criterion. The study of the connections of parts, by no means always enables us to determine whether they 'answer to. one another' or not; and the philosophical anatomists too largely ignored other means of testing their hypotheses.

The constructive efforts of Goethe, with the Philosophic anatomique of France and the Naturphilosophie of Germany on the one hand, the critical negations of the Cuvierian school on the other, do not represent all the lines of biological work in the period under consideration. There is another, which it is the great defect of Cuvier and his school to have underrated and neglected; while it is the great misfortune of Geoffroy that it made its importance fully felt too late for him. This is Embryology, or Development; that is, the study of the manner in which individual living things acquire the structure which they possess.

The science of development, in the modern acceptation of the term, came into existence when Wolff demonstrated the fallacy of the emboítement theory; and also proved that the leaves, the petals, the stamens, and so forth, of flowering plants do, as a matter of fact, start from one and the same primary form in the bud and become differentiated as they grow. It was thus that, thirty years before Goethe saw how the relations of living forms could be ideally represented, Wolff proved what they in fact are. In quite another sense from that of Goethe's reply to Schiller, the embryologist showed cause for the belief that 'unity of organisation' is not an idea, but a fact. The study of the actual process of individual evolution, thus put on a firm foundation, steadily advanced, until Von Baer⁶ arrived at the great generalisation that all such evolution is a progress from relative simplicity to relative complexity in other words, that it is [672] the gradual differentiation of a relatively homogeneous living substance represented by the egg that, in so far as all individual living beings start from ova of essentially similar simplicity of structure, and as the earliest steps of their development or evolution are similar, the fundamental unity of their organisation is a fact; on the other hand, that, in so far as the typical forms of the several groups to which they belong are soon assumed, and, thereafter, each pursues the special line of modification characteristic of its group, 'unity of organisation' soon ceases to be strictly predicable. Thus Geoffroy was right about the fundamental unity of animal organisation, and Cuvier was right about the existence of different types irreducible to one another; while each erred in thinking his own views incompatible with those of his opponent.

In the course of the discussions about the corresponding, or answering, parts in different organisms, or in the same organisms, and. about questions of classification, a very useful terminology had been invented. When the systematists attempted to construct a scientific classification, they found themselves obliged to discriminate between different kinds of resemblances. Take, for example, the question whether a whale is a fish or not, which, I observe, is not yet quite settled for some people. As a whale is not a little like a fish outside, and lives permanently in the sea, after the manner of a fish, why should it not be classed with the fishes? The answer, of course, is that the moment one compares a whale with any one of the thousands of ordinary fishes the two are seen to differ in almost every. particular of structure; and, moreover, in all these points in which the whale differs from the fish it agrees with ordinary mammals. Therefore, zoologists put the whale into the same class as the mammals, not into that of the fishes. But this conclusion implies the assumption that animals should be arranged according to the totality of their resemblances. It means that the likenesses in structure of whales and mammals are greatly more numerous and more close than the likenesses between whales and fishes. The same argumentation applies to the likeness between bats, and birds. These are few and superficial, while the resemblances between bats and ordinary mammals are innumerable and profound. Therefore bats go into the class Mammalia, not into the class Aves. In these cases, the estimation of the relative value of resemblances is easy enough; but, in respect of the lesser groups, the problem offered frequently greater difficulties. Even Cuvier, misled by certain superficial resemblances, could refer the acorn-shells and the barnacles to the class of Mollusks.

[673] Thus, in course of time, there arose in the minds of thoughtful systematists a distinction between 'analogies' and 'affinities;' and, in those of the philosophical anatomists, a corresponding discrimination between 'analogous' and 'homologous' structures. Outward resemblances of the character of those which obtain between a whale and a fish, a bat and a bird, were said to, be mere analogies, and were properly regarded as of no classificatory importance. The deeper structural likenesses between a whale and a seal, or between a bat and a shrew mouse, on the other hand, were affinities that is to say, the exhibitors of such resemblances were 'affined or 'allied' in the sense of belonging to the same, classificatory group.⁷ So, for the anatomists, the shell of a tortoise and the shell of a crab were merely analogous structures; while the bones of the arm of a man and those of the wing of a bird were homologous.

Homology originally signified agreement either of, or about, things. The word, with its derivatives and allies, such as 'homonymous,' passed into Latin, French, and German; and Anglicised forms of them are to be found in Nathan Bailey's 'Dictionary,' now a century and a half old. Even in its present sense, as an anatomical term, homology was wellknown as far back as the early years of this century. Owen, writing in 1846, insists upon the fact that, in using the word, he follows established precedent:–

The last words of the citation from Geoffroy St. Hilaire have a curious significance. Goethe had pointed out, and neither he, nor Geoffroy, nor Oken, were blind to the fact, that the study of development must have a good deal to say about the problems of philosophical anatomy; though, as I have mentioned, that branch of [674] morphology had not advanced far enough to enable Geoffroy to appreciate its full importance, before the publication of Von Baer's works, in the course of the decade 1828 to 1838. But embryology began to show its capacity for playing the part of a criterion in morphology pretty early. It has already been stated that Wolff demonstrated the homology of leaves, stamens, and carpels, by tracing their development. Later, it was readily shown that Vicq d'Azyr's doctrine of the homology of the limbs had its proof in the observation that they arise from rudiments of similar character and relations. In all the higher vertebrate animals, the fore and hind limbs are, at first, very similar, and they become differentiated by successive steps. So the earliest rudiments of the spinal column, and the manner in which it becomes segmented, are alike throughout.

On the other hand, a favourite speculation of the philosophical anatomists, that the lower jaw is formed by the coalescence of a pair of limbs, for which comparative anatomy seemed to offer some support; and Geoffroy's tempting suggestion that the opercular bones of fishes answer to the ear-bones of mammals, were at once negatived by the study of the development of the parts. Again, the hypothesis that the skull consists of modified vertebræ, advocated by Goethe and Oken, and the subject of many elaborate works, was so little reconcilable with the mode of its development that, as early as 1842, Vogt threw well-founded doubts upon it. 'All efforts to interpret the skull in this way,' said he, 'are vain.'

The preceding sketch of the history of anatomical science, though drawn only in broad outline, may suffice to indicate the courses which naturally suggested themselves to any one taking up the subject in the beginning of the fourth decade of the present century.

There was the brilliant example of Cuvier in the 'Anatomie Comparée,' the 'Mémoires sur les Mollusques,' and the 'Ossemens Fossiles,' for any one disposed to devote himself to the increase of the capital stock of knowledge by museum work, or by anatomical .and palæontological monography; there was the path of philosophical anatomy, opened up by Vicq d'Azyr, Goethe, Geoffroy St. Hilaire, Oken, and followed out in the elaborate works of Spix and Carus on the skeleton, with results acutely checked and criticised by Cuvier; there was the study of individual development in its dawn, but with its great future already, clearly indicated by Von Baer; there was the question of the development of animals and plants in general, or what is now commonly understood by the term evolution, waiting to be rescued from the region of speculation, to which it had [675] been relegated for want of positive evidence one way or the other, and a good deal more damaged by its supporters than by its opponents.

It was at this time, namely in 1830, that Owen turned from practical medicine to natural science; and threw himself into the first-mentioned of these paths of exploration, with an energy which reminds one of Geoffroy and Cuvier, when, a little younger, they set out on their remarkable careers. Owen's first recorded publication is an account of an aneurism. The second work in which he engaged was a catalogue of specimens in the museum of the Royal College of Surgeons. But, in the next year (1831), no fewer than eight papers on the anatomy of various mammals, birds, and reptiles which had died in the Zoological Gardens bear his name. This was a pretty good start for a young man of twenty-six to make; but the harvest of the year 1832 bettered that of its predecessor. For without any other work, Owen's time might, one would think, have been fully occupied by the famous 'Memoir on the Pearly Nautilus,' which was published in 1832 and placed its author, at a bound, in the front rank of anatomical monographers. There is nothing better in the 'Memoires sur les Mollusques,' I would even venture to say nothing so good, were it not that Owen had Cuvier's great work for a model; certainly, in the sixty years that have elapsed since the publication of this remarkable monograph, it has not been excelled; and that is, a good deal to say with Müller's 'Myxinoid Fishes' for a competitor.

During more than half a century, Owen's industry remained unabated: and whether we consider the quantity, or the quality, of the work done, or the wide range of his labours I doubt if, in the long annals of anatomy, more is to be placed to the credit of any single worker.

The preparation of the five volumes of the descriptive catalogue of the Hunterian Museum and of the annual courses of lectures demanded from the Huntetian Professor, took Owen over the length and breadth of the animal kingdom and involved the making of special investigations in almost all its provinces. The wide knowledge thus accumulated was eventually summed up and published, first in the lectures on the Invertebrates (1843) and, secondly, in those on the Vertebrates (1860-1868).

As methodically arranged and comprehensive repertories of the anatomy of animals, it may be a question whether these works are equal to the contemporary 'Handbuch' of Siebold and Stannius; but, it may quite safely be said of them, that they are based on the results [676] of a greater amount of personal investigation than any work of the kind except, perhaps Cuvier's 'Legons;' and I put the exception doubtfully, inasmuch as Cuvier was aided by highly skilled assistants.

Further, I think that Owen's monographic work occupies a unique position, if one considers, not merely its general high standard of excellence, but the way in which so many of these memoirs have opened up new regions of investigation. I mention the following, as some of the most important from this point of view, in addition to that on the Pearly Nautilus, to which 1 have already referred.

To begin with the higher animals, Owen's early memoirs on the anatomy of the anthropoid Apes contained by far the most complete and adequate account of their structure, and of the resemblances and differences between them and man, then extant; and they formed the foundation of all subsequent researches in that field. The same may be said of his investigations on the Monotremes and Marsupials, the substance of which is, for the most part, incorporated in the well-known articles of the 'Cyclopædia of Anatomy, and Physiology.' These remained, for many years, indeed are still, in most respects, the best source of information about these animals.

The researches on the minute structure and the development of the teeth, summed up in the 'Odontography' (1840-45), and the article 'Odontology,"⁹ so far as they deal with the outward form, the microscopic appearances, and the order of succession of the teeth, and furnish a foundation for a useful and consistent nomenclature of dental arrangements, have been of very great service both to the ordinary zoologist and to the student of fossil remains.

In regard to the class of birds, the memoirs on the Apteryx, the Great Auk, and the Dodo are particularly noteworthy; and, the article 'Aves' in the 'Cyclopædia of Anatomy and Physiology' very long held its own, as the best summary of avian structure.

The paper on 'Lepidosiren' left no doubt of the piscine affinities of that animal.

Among the Invertebrates we have the article 'Cephalopoda' (1836), the 'Memoir on Limulus' (1873), the 'Researches on the Brachiopoda' (1833), and the description of the terrible parasite of mari, Trichina spiralis.

In regard to Taxonomy, Owen made a variety of proposals, the consideration of most of which would involve discussions altogether out of place in this sketch. But there is a notable exception [677] in the case of the attempt to develop Cuvier's idea of the classification of pachyderms by the number of their toes' appended to the 'description of teeth and portions of jaws of two extinct anthracotherioid quadrupeds (Hyobolamus vectianus and H. bovinus)' (1848), as to the high value of which I think all zoologists are agreed.

In 1837, Owen, without any pause in the long and important series of anatomical investigations which have been mentioned, began those contributions to palæontology which, in after years, perhaps contributed most to his fame with the public. His first work in this department is a memoir, published in the second volume of the Proceedings of the Geological Society, on an extinct mammal discovered in South America by Darwin in 1833, which Owen named Toxodon Platensis. It is worthy of notice that, in the title of this memoir, there follow, after the name of the species, the words 'referable by its dentition to the Rodentia, but with affinities to the Pachydermata and the herbivorous Cetacea ;' indicating the importance in the mind of the writer of the fact that, like Cuvier's Anoplotherium and Palæotherium, Toxodon occupied a position between groups which, in existing nature, are now widely separated. The existence of one more extinct 'intercalary' type was established.

From another point of view, this maiden essay in palæontology possesses great interest.

It is with reference to Owen's report upon the remains of Toxodon that Darwin remarks in his journal, six years later: 'How wonderfully are the different orders, at the present time so well separated, blended together in different points of the. structure of the Toxodon!' while, in his pocket-book for 1837, he records: 'In July opened first notebook on Transmutation of Species. Had been greatly struck from about the month of previous March on character of South American fossils, and species on Galapagos Archipelago. These facts (especially latter) origin of all my views."¹⁰

Unless it be in the 'Ossemens Fossiles,' I do not know where one is to look for contributions to palæontology more varied, more numerous, and, on the whole, more accurate, than those which Owen poured forth in rapid succession between 1837 and 1888. Yet there was no lack of strong contemporaries at work in the same field. De Blainville's 'Ostéographie;' Louis Agassiz's monumental work on fossil fishes, achieved under the pressure of great obstacles and full of brilliant suggestions; von Meyer's long series of wonderfully accurate memoirs, with their admirable illustrations executed by his own hands, all belong to Owen's generation. But, perhaps the [678] fairest comparison is with Cuvier; and I do not think that those who have had to concern themselves with these subjects will rank any of Cuvier's memoirs higher than those of Owen on Mylodon, Megatherium, Glyptodon, Macrauchenia, and other extinct South American animals, which followed up the account of Toxodon.

In 1838 appeared the memoir on the Stonefield Slate mammals, then the oldest known, pointing out their marsupial affinities, and with this the later investigations on the Purbeck mammals may be grouped. In 1839-40, we have the first indication of the wingless birds of New Zealand, widening out, in after years, into the long series of memoirs on Dinornis and the like. In 1841, the description of the triassic Labyrinthodonts of Central England, which, with Von Meyer's earlier and later work, was the commencement of the elucidation of the triassic fauna in all quarters of the world, made its appearance. In 1844, Owen published the memoir on Belemnites, which had a distinct value, though not perhaps quite that assigned to it at the time. In 1845, followed the first view of the wonderful extinct faunæ of South Africa and Australia, so largely extended by Owen himself in later years. In 1849, the first of the long series of memoirs on British fossil reptiles appeared; in 1863, the description of the famous reptilian bird Archæopteryx.

It is a splendid record; enough, and more than enough, to justify the high place in the scientific world which Owen so long occupied. If I mistake not, the historian of comparative anatomy and of palæontology will always assign to Owen a place next to, and hardly lower than that of Cuvier, who was practically the creator of those sciences in their modern shape; and whose works must always remain models of excellence in their kind. It was not uncommon to hear our countryman called 'the British Cuvier,' and so far, in my judgment, the collocation was justified, high as the praise it implies.

But when we consider Owen's contributions to 'philosophical anatomy,' I think the epithet ceases to be appropriate. For there can be no question that he was deeply influenced by, and inclined towards, those speculations of Oken and Geoffroy St. Hilaire, of which Cuvier was the declared antagonist and often the bitter critic.

That Owen was strongly attracted by the Naturphilosophie of Germany is evidenced, not merely by his attitude towards the problems of philosophical anatomy, but by his article on Oken in the 'Encyclopædia Britannica;' and by the fact that the translation of Oken's 'Lehrbuch der Naturphilosophie' was undertaken at his [679] instance. Thus, when Owen passes from matters of anatomical fact and their immediate interpretation to morphological speculation, it is not surprising that he also passes from the camp of Cuvier into that of his adversaries.

In the advertisement of the work 'On the Archetype and Homologies of the Vertebrate Skeleton,' published in 1848, Owen says:

In fact, what I may call 'Okenism' colours Owen's whole cast of thought on these matters, and his admiration for Oken finds frequent vent in his writings. Thus, in a note at p. 8 of the 'Archetype and Homologies of the Vertebrate Skeleton' (1848), we find:

And the 'Conclusion' of the same work (pp. 171-172) abounds in the sense of the Okenian philosophy. The explanation of the facts of morphology is sought in the 'principle of vegetative repetition;' in the interaction of a 'general and all-pervading polarising force,' with an 'adaptive or special organising force,' identified with the Platonic idea. Whether they be sound or unsound, nothing can be more opposed to the Cuvierian tradition than speculations of this order.

The 'Programm' to which these sympathetic references are made, opens with some sentences which are worth attention, since they furnish a typical example of the speculative procedure of the Naturphilosophie school.

All this may be in accordance with the 'Idée,' and demonstrable a priori; but the plain, prosaic inquirer into objective truth may be excused if he finds nothing in it but a series of metaphorical mystifications; for which, so far as they are to be taken seriously, no empirical justification ever existed. There is not, and there never was, any ground for believing that a vertebra is an ossified vesicle; or that a vertebral column, or a trunk skeleton, is produced in the way asserted; or that a head is a repeated pelvis, or vice versa; while the intelligibility of the final assertion that 'the entire man is only a vertebra,' is not apparent. The spirit which animates these oracular utterances pervades all the writings of Oken and his school; it provided Cuvier with the subject-matter of his severest, as well as of his most justifiable sarcasms; and every one who has the interests of sound science at heart must feel Cuvier's debtor for the pertinacity with which lie combated, and finally drove out of the field of science, this pseudo-philosophical word-play.

I do not for a moment suggest, indeed I cannot imagine, that Owen approved of such extravagances as those which, I have cited; but that he was deeply influenced by the philosophy of Oken, bringing it, apparently, in his own mind into harmony with that of the English Platonists, and especially of Cudworth, is a conclusion which can hardly be avoided. The following passages alone appear to me to be decisive:

Those who know Owen's mind only on the side reflected in the exact observations, the clear-headed and sagacious interpretations, of the anatomical and palæontological memoirs, should ponder over these and other passages of like tenor, if they wish to form a just judgment about the position which he took up in morphology; and, later, in regard to the Darwinian revivification of the doctrine of evolution. On the speculative side, the very same mind has a distinct leaning towards realistic mysticism, while remaining liberally, perhaps prodigally, eclectic. A sublimated Theism, after the manner of Cudworth, lies at the foundation of Owen's speculations; while the 'Archetype' takes the position of a Platonic idea, indeed, almost that of an Alexandrian logos. The essentially naturalistic abstractions–'secondary causes,' 'forces,' and 'Polarity'–are personified and regarded as agents.

If, in the 'Nature of Limbs' (pp. 84, 85), the argument from Design is momentarily shattered by the admission that some parts of animals are 'made in vain;' it is immediately redintegrated by the suggestion that they are illustrations of the design manifested in the 'Archetype.' The looking to 'natural laws' and 'secondary causes' for the 'progression' of organic phenomena' is the substantial acceptance of evolution, as set forth by Goethe, Oken, Lamarck, and Geoffroy; but the picture of 'Nature,' advancing 'amidst the wreck of worlds,' fits in, no less admirably, with the catastrophism of Cuvier.

Owen's morphological labours appear to me to be completely pervaded by the spirit, and restricted to the methods, of the philosophical anatomists; if I may, for the nonce, use that name in a [682] limited sense, for the scholars of Oken, rather than for those of Geoffroy. But, from this point of view, the theory of the vertebrate skeleton had been so elaborately worked out by Spix (1815), Carus (1828), and others, that the vein might well seem to be exhausted. Carus, especially, had visualized his hypotheses in diagrams, to which he gave the names of 'Grundform' and 'Schema;' and which are the equivalents of the 'Archetype' and its derivatives. Thus, when Owen took up the subject, many years after Carus, there really was nothing new in principle to be done, so long as the method of his predecessors was followed. All that could be hoped from renewed investigation, along the same lines, was the rectification of erroneous, and the suggestion of unsuspected, homologies. And this is what we find; new homologies for the cranial bones; original speculations respecting the nature of the bony walls of the inferior cavities of the skull; as to the proper connections and homology of the pectoral arch; and so on.

I believe I am right in saying that hardly any of these speculations and determinations have stood the test of investigation, or, indeed, that any of them were ever widely accepted. I am not sure that any one but the historian of anatomical science is ever likely to recur to them; and considering Owen's great capacity, extensive learning, and tireless industry, that seems a singular result of years of strenuous labour.

But it will cease to be so remarkable to those who reflect that the ablest of us is a child of his time, profiting by one set of its influences, limited by another. It was Owen's limitation that he occupied himself with speculations about the 'Archetype' some time before the work of the embryologists began to be appreciated in this country. It had not yet come to be understood that, after the publication of the investigations of Rathke, Reichert, Remak, Vogt, and others, the venue of the great cause of the morphology of the skeleton was removed from the court of comparative anatomy to that of embryology.¹⁵ When developmental investigation had proved that even the segmentation of the vertebrate body is not its primary condition; that such segmentation without founding it largely on embryology cannot be traced throughout the cranial region; that a process of chondrification, or formation of cartilaginous hard-parts, precedes ossification, and is not the same in the skull as in the spinal column; that bones [683] are not all similar in respect of their mode of origin; it was obvious that no satisfactory theory of the skeleton could be attained without taking these facts into serious consideration, and, indeed, without founding it largely on embryology.

It would be a great mistake, however, to conclude that Owen's labours in the field of morphology wore lost, because they have yielded little fruit of the kind he looked for. On the contrary, they not only did a great deal of good by awakening attention to the higher problems of morphology in this couritry; but they were of much service in clarifying and improving anatomical nomenclature, especially in respect of the vertebral region.

Apart from questions of classification, the only special work of Owen which deals directly with the greater problems of biology, is the discourse on 'Parthenogenesis, or the Successive Production of Procreating Individuals from a single Ovum,' originally delivered in the form of the opening two lectures of the Hunterian Course for 1849.

In these discourses, an attempt is made to correlate, and furnish an explanation of, the phenomena of sexless proliferation; that is to say, of the production of offspring by a plant or an animal, without the intervention of sex. In the vegetable world, such phenomena, as exemplified by the growth and detachment of buds or bulbs, or of young plants, like those formed on strawberry 'runners,' have been known from time immemorial; among animals, they were first carefully elucidated by Trembley and Bonnet in the middle of the eighteenth century.

One of the commonest and most striking cases is that of the plant lice, or Aphides, which are the commonest of pests in our gardens. The young, which these animals produce with such wonderful fertility in summer, are all fatherless. So are the drones in a hive of bees.

Among the aphides, this state of things, as a rule, persists throughout the summer; and it is not until the autumn arrives that the broods produced take on the characters of males and females, which die after their functions are performed and the eggs are laid. The eggs remain dormant during the winter; and when they hatch, in spring, the aphides produced are sexless, though in some respects they resemble the true females. These sexless forms produce living broods, having the same characters as, their producer; and these give rise to others, in like manner, through the summer. It has been proved that this state of things may be maintained for three years, by keeping the insects warm and supplied with food; indeed, there is no positive evidence that it need ever come to an end.

[684] The males and females are, in many respects, different from the sexless proliferators. Thus, to superficial observation, it appears as if the sexed 'generation,' which may be called the form A, was succeeded by a certain number of sexless 'generations' of the form B; these by A, these by B again, and so on. In other words, the 'generations' A and B alternate.

In the course of the early decades of the nineteenth century, the wide extension of exact investigation among the lower groups of the animal kingdom, especially the polypes, worms, star-fishes, ascidians, crustacea, and insects, brought to light a great number of new facts of the same order; and, in 1842, the Danish zoologist, Steenstrupy collected all of them known at that time, and applied to the phenomena the general formula of the 'Alternation of Generations.' He was met, at the outset, by a difficulty of nomenclature. In the majority of cases, the one term, or the one set of terms, of the alternation is sexless. The germs from which its offspring are produced are not true eggs and are uninftuenced by males. Therefore, it is obviously inexact to call these proliferating forms 'females.' Steenstrup got over the difficulty by terming them 'nurses;' though, thereby, he undoubtedly somewhat strained the usually admitted attributes of a nurse. I do not imagine that Steenstrup supposed that he had contributed anything towards the explanation of these remarkable phenomena by the nomenclature he proposed. However this may be, his work was of' much use by drawing the attention of biologists to their general nature, no less than by bringing into one view all the various forms of proliferation which are exhibited by living matter, and all the physical and metaphysical difficulties, with which the problem of animal and vegetable individuality bristles. Objections might be raised to the term 'Parthenogenesis,' used by Owen, not merely for the autonomous proliferation of true females, but for the production of progeny by organisms which are not really female, and the vestalship of which is therefore physically indefeasible. In fact, it is strictly applicable only to a comparatively few cases among insects and crustacea. And even here, the queen-bee, under ordinary circumstances, would have to be excluded. The fatherless drones are, usually, not merely produced by a true female; but she is already mother, in the ordinary sense, of thousands of daughters.

But questions of names are of no particular importance. We know what the processes denoted by the term 'Parthenogenesis' are; and the point is to ascertain how far Owen's work contributed to a better knowledge of them; or to that construction of an explanation of the phenomena which is the end of investigation.

[685] With respect to the first point, the work on 'Parthenogenesis' contains no addition, that I am aware of, to the common stock of observed facts. In truth, the great majority of the subjects of these processes are either the smaller insects and crustacea, which lay out of Owen's range of study; or the marine invertebrates, which were, in those days, hardly accessible to any but persons who lived on, or by, the sea. Moreover, the investigation lay eminently in the province of the histological microscopist, in which Owen was less at home than elsewhere.

In trying to form a judgment of the value of the explanation offered, it is a necessary preliminary to consider what there was to explain.

Among the animals with which we are familiar, proliferation, or the production of offspring, invariably implies the concurrence of two parents, a father and a mother. We are, therefore, naturally led to regard this method of proliferation as the rule, and any other as an exception. But, as we have seen, if our daily experience had been derived from many of the lower animals and plants, we might just as well have been led to think sexless proliferation the rule, and the other the exception. Whatever the outward form of the process of proliferation, in substance it always comes to the same thing. It is the detachment of a parcel, A, of the living substance of the parent, which either before, or after, detachment evolves into a complete, physiologically independent, organism. There are innumerable cases in which this. process takes place, in virtue of the autonomous activities of the living substance of an organism. The progeny in this case is a detached fragment of A, and nothing else. Why is it that, in equally numerous other cases, a parcel of the same kind may be similarly detached from A, but does not evolve, unless another parcel, B, of living substance, derived from the same, or another, organism, not merely comes into contact with A, but fuses with it; so that the substance of the progeny is A + B, and not merely A? What we want to explain is, not only why sexless proliferation takes place in the animals or plants in which it occurs, but why it does not take place in other closely allied forms. It is not legitimate to assume that sexless proliferation is secondary and exceptional; and sexual proliferation primary and normal. On the face of the matter, it is just as likely to be the other way.

In the essay under consideration, however, Owen starts with this assumption. He conceives that B is the agent by which a certain 'spermatic force' is transmitted to A; and that, when apparently sexless proliferation takes place, the evolution of the germs is really due to the presence in them of this hypothetical 'spermatic force,' [686] transmitted from the first sexual proliferation. Starting from the established truth that, where sex is concerned, the essential step of the production of progeny is the coalescence of substances contained in two cells, one derived from the one parent, and one from the other, and the subsequent division and subdivision (with concomitant growth) of the combined mass into the primary cells of which the embryo is constructed, Owen goes on to say (p. 5):

Again (P. 72):

But the primary assumption that this 'spermatic force' is necessary to the evolution of germs, that., therefore, sexless proliferation is only, as it were, sexual proliferation, one or more degrees removed, begs the whole question, which is exactly whether spermatic influence is, or is not, necessary to proliferation.

The other part of Owen's hypothesis, that proliferation depends upon the presence, in the proliferating region, of unchanged de[687]scendants of the primitive spermatized cells of the embryo, could not and cannot be supported by observation; and is, indeed, contradicted by plain facts. In mosses, for example, there are very few parts of the whole organism which will not, under favourable circumstances, give rise to bud-like germs, whence new mosses proceed. And, in closely allied animals, in which the cells of the respective ovaries are equally near in descent to those of the embryo, the one will regularly proliferate, without male influence, and the other will never do so.

Owen, in fact, got no further towards the solution of this wonderful and difficult problem than Morren and others had done before him. But it is an interesting circumstance that the leading idea of 'Parthenogenesis;' namely, that sexless proliferation is, in some way, dependent upon the presence, in the prolifying region, of relatively unaltered descendants of the primary impregnated embryo cell (A + B)–is at the bottom of most of the attempts which have recently been made to deal with the question. The theory of the continuity of germ-plasm of Weismann, for example, is practically the same as Owen's, if we omit from the latter the notion that the endowment with 'spermatic force' is the indispensable condition of proliferation. The great progress of knowledge, about these matters, since 1849, lies in the demonstration of the importance of a certain formed material which is met with in the nuclei of cells; of the fact that this substance, growing and dividing, is distributed from the nucleus of the primary cell to the nuclei of all the cells of the organism; that, in sexual proliferation, the nuclear substances of A and B pass, bodily, into the nucleus of the resulting embryo cell, without losing their independence, and are similarly transmitted to all the cells of the adult; whence it follows that every histological element of the adult living body thus produced contains associated, but yet materially distinct, descendants of the nuclear elements derived from each parent.

This discovery ranks, in my judgment, as the greatest achievement of morphological science since the establishment of the cell theory.¹⁶ Its importance as a factor in every theory of heredity is obvious; and it must have an equally important influence upon all theories of proliferation. But, for the present, I must express the opinion that it affords very little more help towards a scientific explanation of the phenomena of 'Parthenogenesis' than Owen's theory afforded in the infancy of histological inquiry. Except by the help of assumptions, of which there is no proof, I do not see that [688] modern speculation, at present, gives us any better explanation why the leaves of some plants prolify readily and regularly, while those of others never do so; or why female cockroaches never exhibit sexless proliferation while queen-bees always do so. The ingenuity which fits hypotheses to facts by the help of other hypotheses is always worthy of admiration; but, if it is to be useful, its purely speculative character should never be lost sight of. If science is to retain its strength, it must keep in touch with the solid ground of observation. In reading some of the biological literature of the present day, I sometimes rub my eyes and wonder whether I am not dreaming of the good old days of the Naturphilosophie.

In the preceding pages I have endeavoured to give the general reader an outline sketch of the scope and the course of modern biological science; of the condition of its several great divisions when Sir R. Owen commenced his career sixty-four years ago; of the influence of his work upon the extraordinarily rapid advance of biology in the course of that time; and it may be well that, arrived at the end of my task, I recall my allusion, at the outset, to the special difficulties in the way of the satisfactory performance of it.

It does not appear to me that anything need be said here about the many scientific controversies in which Owen was engaged. I should be of this opinion if I had not been concerned in any of them; for I do not see what good is to result from the revival of the memory of such conflicts. And whether 1 am right or wrong in this opinion, I am well assured that, if anything is to be said upon this topic, I am not the proper person to say it.

But notwithstanding my determination to ignore controversies, and a strong desire to appreciate rather than to criticise, I am sensible that the discussion of the 'Archetype' and of 'Parthenogenesis' not merely allows the wide differences of opinion, which unhappily obtained between Sir R. Owen and myself, to appear, but occupies an amount of space which may be thought excessive, in relation to that filled by my endeavour to do justice to the great and solid achievements in Comparative Anatomy and Palæontology which I have recounted.

But this really lay in the nature of things. Obvious as are the merits of Owen's anatomical and palæontological work to every expert, it is necessary to be an expert to discern them; and endless pages of analysis of his memoirs would not have made the general reader any wiser than he was at first. On the other hand, the nature of the broad problems of the 'Archetype' and of 'Parthenogenesis' [689] may easily be stated in such a way as to be generally intelligible; while from Goethe to Zola, poets and novelists have made them interesting to the public. I have, therefore, permitted myself to dwell upon these topics at some length; but the reader must bear in mind that, whatever view is taken of Sir Richard Owen's speculations on these subjects, his claims to a high place among those who have made great and permanently valuable contributions to knowledge remain unassailable.

¹ It will be understood that the separation between Morphology and Physiology can be maintained only so long as the view is confined to the phenomena of form or to those of function. Both are equally important to the aetiologist, who seeks for the causes of biological phenomena.

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