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rock builders.

What has been said of the animal world is no less true of plants. Imbedded in the protoplasm at the broad, or attached, end of the nettle hair, there lies a spheroidal nucleus. Careful examination further proves that the whole substance of the nettle is made up of a repetition of such masses of nucleated protoplasm, each contained in a wooden case, which is modified in form, sometimes into a woody fibre, sometimes into a duct or spiral vessel, sometimes into a pollen grain, or an ovule. Traced back to its earliest state, the nettle arises as the man does, in a particle of nucleated protoplasm. And in the lowest plants, as in the lowest animals, a single mass of such protoplasm may constitute the whole plant, or the protoplasm may exist without a nucleus.

Under these circumstances it may well be asked, how is one mass of non-nucleated protoplasm to be distinguished from another? why call one “plant” and the other “animal”?

The only reply is that, so far as form is concerned, plants and animals are not separable, and that, in many cases, it is a mere matter of convention whether we call a given organism an animal or a plant. There is a living body called Aethalium septicum, which appears upon decaying vegetable substances, and, in one of its forms, is common upon the surfaces of tan-pits. In this condition it is, to all intents and purposes, a fungus, and formerly was always regarded as such; but the remarkable investigations of De Bary [99] have shown that, in another condition, the Aethalium is an actively locomotive creature, and takes in solid matters, upon which, apparently, it feeds, thus exhibiting the most characteristic feature of animality. Is this a plant; or is it an animal? Is it both; or is it neither? Some decide in favour of the last supposition, and establish an intermediate kingdom, a sort of biological No Man’s Land [100] for all these questionable forms. But, as it is admittedly impossible to draw any distinct boundary line between this no man’s land and the vegetable world on the one hand, or the animal, on the other, it appears to me that this proceeding merely doubles the difficulty which, before, was single.

Protoplasm, simple or nucleated, is the formal basis of all life. It is the clay of the potter: which, bake it and paint it as he will, remains clay, separated by artifice, and not by nature, from the commonest brick or sun-dried clod.

Thus it becomes clear that all living powers are cognate, and that all living forms are fundamentally of one character. The researches of the chemist have revealed a no less striking uniformity of material composition in living matter.

In perfect strictness, it is true that chemical investigation can tell us little or nothing, directly, of the composition of living matter, inasmuch as such matter must needs die in the act of analysis,–and upon this very obvious ground, objections, which I confess seem to me to be somewhat frivolous, have been raised to the drawing of any conclusions whatever respecting the composition of actually living matter, from that of the dead matter of life, which alone is accessible to us. But objectors of this class do not seem to reflect that it is also, in strictness, true that we know nothing about the composition of any body whatever, as it is. The statement that a crystal of calc-spar consists of carbonate of lime, is quite true, if we only mean that, by appropriate processes, it may be resolved into carbonic acid and quicklime. If you pass the same carbonic acid over the very quicklime thus obtained, you will obtain carbonate of lime again; but it will not be calc-spar, nor anything like it. Can it, therefore, be said that chemical analysis teaches nothing about the chemical composition of calc-spar? Such a statement would be absurd; but it is hardly more so than the talk one occasionally hears about the uselessness of applying the results of chemical analysis to the living bodies which have yielded them.

One fact, at any rate, is out of reach of such refinements, and this is, that all the forms of protoplasm which have yet been examined contain the four elements, carbon, hydrogen, oxygen, and nitrogen, in very complex union, and that they behave similarly towards several reagents. To this complex combination, the nature of which has never been determined with exactness, the name of Protein has been applied. And if we use this term with such caution as may properly arise out of our comparative ignorance of the things for which it stands, it may be truly said, that all protoplasm is proteinaceous, or, as the white, or albumen, of an egg is one of the commonest examples of a nearly pure proteine matter, we may say that all living matter is more or less albuminoid.

Perhaps it would not yet be safe to say that all forms of protoplasm are affected by the direct action of electric shocks; and yet the number of cases in which the contraction of protoplasm is shown to be affected by this agency increases every day.

Nor can it be affirmed with perfect confidence, that all forms of protoplasm are liable to undergo that peculiar coagulation at a temperature of 40-50 degrees centigrade, which has been called “heat-stiffening,” though Kuhne’s [101] beautiful researches have proved this occurrence to take place in so many and such diverse living beings, that it is hardly rash to expect that the law holds good for all.

Enough has, perhaps, been said to prove the existence of a general uniformity in the character of the protoplasm, or physical basis, of life, in whatever group of living beings it may be studied. But it will be understood that this general uniformity by no means excludes any amount of special modifications of the fundamental substance. The mineral, carbonate of lime, assumes an immense diversity of characters, though no one doubts that, under all these Protean changes, it is one and the same thing.

And now, what is the ultimate fate, and what the origin, of the matter of life?

Is it, as some of the older naturalists supposed, diffused throughout the universe in molecules, which are indestructible and unchangeable in themselves; but, in endless transmigration, unite in innumerable permutations, into the diversified forms of life we know? Or, is the matter of life composed of ordinary matter, differing from it only in the manner in which its atoms are aggregated? Is it built up of ordinary matter, and again resolved into ordinary matter when its work is done?

Modern science does not hesitate a moment between these alternatives. Physiology writes over the portals of life–

“Debemur morti nos nostraque,”[102]

with a profounder meaning than the Roman poet attached to that melancholy line. Under whatever disguise it takes refuge, whether fungus or oak, worm or man, the living protoplasm not only ultimately dies and is resolved into its mineral and lifeless constituents, but is always dying, and, strange as the paradox may sound, could not live unless it died.

In the wonderful story of the Peau de Chagrin,[103] the hero becomes possessed of a magical wild ass’ skin, which yields him the means of gratifying all his wishes. But its surface represents the duration of the proprietor’s life; and for every satisfied desire the skin shrinks in proportion to the intensity of fruition, until at length life and the last handbreadth of the peau de chagrin, disappear with the gratification of a last wish.

Balzac’s [104] studies had led him over a wide range of thought and speculation, and his shadowing forth of physiological truth in this strange story may have been intentional. At any rate, the matter of life is a veritable peau de chagrin, and for every vital act it is somewhat the smaller. All work implies waste, and the work of life results, directly or indirectly, in the waste of protoplasm.

Every word uttered by a speaker costs him some physical loss; and, in the strictest sense, he burns that others may have light–so much eloquence, so much of his body resolved into carbonic acid, water, and urea. It is clear that this process of expenditure cannot go on for ever. But, happily, the protoplasmic peau de chagrin differs from Balzac’s in its capacity of being repaired, and brought back to its full size, after every exertion.

For example, this present lecture, whatever its intellectual worth to you, has a certain physical value to me, which is, conceivably, expressible by the number of grains of protoplasm and other bodily substance wasted in maintaining my vital processes during its delivery. My peau de chagrin will be distinctly smaller at the end of the discourse than it was at the beginning. By and by, I shall probably have recourse to the substance commonly called mutton, for the purpose of stretching it back to its original size. Now this mutton was once the living protoplasm, more or less modified, of another animal–a sheep. As I shall eat it, it is the same matter altered, not only by death, but by exposure to sundry artificial operations in the process of cooking.

But these changes, whatever be their extent, have not rendered it incompetent to resume its old functions as matter of life. A singular inward laboratory, which I possess, will dissolve a certain portion of the modified protoplasm; the solution so formed will pass into my veins; and the subtle influences to which it will then be subjected will convert the dead protoplasm into living protoplasm, and transubstantiate sheep into man.

Nor is this all. If digestion were a thing to be trifled with, I might sup upon lobster, and the matter of life of the crustacean would undergo the same wonderful metamorphosis into humanity. And were I to return to my own place by sea, and undergo shipwreck, the crustacean might, and probably would, return the compliment, and demonstrate our common nature by turning my protoplasm into living lobster. Or, if nothing better were to be had, I might supply my wants with mere bread, and I should find the protoplasm of the wheat-plant to be convertible into man, with no more trouble than that of the sheep, and with far less, I fancy, than that of the lobster.

Hence it appears to be a matter of no great moment what animal, or what plant, I lay under contribution for protoplasm, and the fact speaks volumes for the general identity of that substance in all living beings. I share this catholicity of assimilation with other animals, all of which, so far as we know, could thrive equally well on the protoplasm of any of their fellows, or of any plant; but here the assimilative powers of the animal world cease. A solution of smelling-salts in water, with an infinitesimal proportion of some other saline matters, contains all the elementary bodies which enter into the composition of protoplasm; but, as I need hardly say, a hogshead of that fluid would not keep a hungry man from starving, nor would it save any animal whatever from a like fate. An animal cannot make protoplasm, but must take it ready-made from some other animal, or some plant–the animal’s highest feat of constructive chemistry being to convert dead protoplasm into that living matter of life which is appropriate to itself.

Therefore, in seeking for the origin of protoplasm, we must eventually turn to the vegetable world. A fluid containing carbonic acid, water, and nitrogenous salts, which offers such a Barmecide feast [105] to the animal, is a table richly spread to multitudes of plants; and, with a due supply of only such materials, many a plant will not only maintain itself in vigour, but grow and multiply until it has increased a million-fold, or a million million-fold, the quantity of protoplasm which it originally possessed; in this way building up the matter of life, to an indefinite extent, from the common matter of the universe.

Thus, the animal can only raise the complex substance of dead protoplasm to the higher power, as one may say, of living protoplasm; while the plant can raise the less complex substances– carbonic acid, water, and nitrogenous salts–to the same stage of living protoplasm, if not to the same level. But the plant also has its limitations. Some of the fungi, for example, appear to need higher compounds to start with; and no known plant can live upon the uncompounded elements of protoplasm. A plant supplied with pure carbon, hydrogen, oxygen, and nitrogen, phosphorus, sulphur, and the like, would as infallibly die as the animal in his bath of smelling-salts, though it would be surrounded by all the constituents of protoplasm. Nor, indeed, need the process of simplification of vegetable food be carried so far as this, in order to arrive at the limit of the plant’s thaumaturgy. Let water, carbonic acid, and all the other needful constituents be supplied except nitrogenous salts, and an ordinary plant will still be unable to manufacture protoplasm.

Thus the matter of life, so far as we know it (and we have no right to speculate on any other), breaks up, in consequence of that continual death which is the condition of its manifesting vitality, into carbonic acid, water, and nitrogenous compounds, which certainly possess no properties but those of ordinary matter. And out of these same forms of ordinary matter, and from none which are simpler, the vegetable world builds up all the protoplasm which keeps the animal world a-going. Plants are the accumulators of the power which animals distribute and disperse.

But it will be observed, that the existence of the matter of life depends on the pre-existence of certain compounds; namely, carbonic acid, water, and certain nitrogenous bodies. Withdraw any one of these three from the world, and all vital phaenomena come to an end. They are as necessary to the protoplasm of the plant, as the protoplasm of the plant is to that of the animal. Carbon, hydrogen, oxygen, and nitrogen are all lifeless bodies. Of these, carbon and oxygen unite in certain proportions and under certain conditions, to give rise to carbonic acid; hydrogen and oxygen produce water; nitrogen and other elements give rise to nitrogenous salts. These new compounds, like the elementary bodies of which they are composed, are lifeless. But when they are brought together, under certain conditions, they give rise to the still more complex body, protoplasm, and this protoplasm exhibits the phaenomena of life.

I see no break in this series of steps in molecular complication, and I am unable to understand why the language which is applicable to any one term of the series may not be used to any of the others. We think fit to call different kinds of matter carbon, oxygen, hydrogen, and nitrogen, and to speak of the various powers and activities of these substances as the properties of the matter of which they are composed.

When hydrogen and oxygen are mixed in a certain proportion, and an electric spark is passed through them, they disappear, and a quantity of water, equal in weight to the sum of their weights, appears in their place. There is not the slightest parity between the passive and active powers of the water and those of the oxygen and hydrogen which have given rise to it. At 32 degrees Fahrenheit, and far below that temperature, oxygen and hydrogen are elastic gaseous bodies, whose particles tend to rush away from one another with great force. Water, at the same temperature, is a strong though brittle solid whose particles tend to cohere into definite geometrical shapes, and sometimes build up frosty imitations of the most complex forms of vegetable foliage.

Nevertheless we call these, and many other strange phaenomena, the properties of the water, and we do not hesitate to believe that, in some way or another, they result from the properties of the component elements of the water. We do not assume that a something called “aquosity” entered into and took possession of the oxidated hydrogen as soon as it was formed, and then guided the aqueous particles to their places in the facets of the crystal, or amongst the leaflets of the hoar-frost. On the contrary, we live in the hope and in the faith that, by the advance of molecular physics, we shall by and by be able to see our way as clearly from the constituents of water to the properties of water, as we are now able to deduce the operations of a watch from the form of its parts and the manner in which they are put together.

Is the case in any way changed when carbonic acid, water, and nitrogenous salts disappear, and in their place, under the influence of pre-existing living protoplasm, an equivalent weight of the matter of life makes its appearance?

It is true that there is no sort of parity between the properties of the components and the properties of the resultant, but neither was there in the case of the water. It is also true that what I have spoken of as the influence of pre-existing living matter is something quite unintelligible; but does anybody quite comprehend the modus operandi [106] of an electric spark, which traverses a mixture of oxygen and hydrogen?

What justification is there, then, for the assumption of the existence in the living matter of a something which has no representative, or correlative, in the not living matter which gave rise to it? What better philosophical status has “vitality” than “aquosity”? And why should “vitality” hope for a better fate than the other “itys” which have disappeared since Martinus Scriblerus [107] accounted for the operation of the meat-jack [108] by its inherent “meat-roasting quality,” and scorned the “materialism” of those who explained the turning of the spit by a certain mechanism worked by the draught of the chimney.

If scientific language is to possess a definite and constant signification whenever it is employed, it seems to me that we are logically bound to apply to the protoplasm, or physical basis of life, the same conceptions as those which are held to be legitimate elsewhere. If the phaenomena exhibited by water are its properties, so are those presented by protoplasm, living or dead, its properties.

If the properties of water may be properly said to result from the nature and disposition of its component molecules, I can find no intelligible ground for refusing to say that the properties of protoplasm result from the nature and disposition of its molecules.

But I bid you beware that, in accepting these conclusions, you are placing your feet on the first rung of a ladder which, in most people’s estimation, is the reverse of Jacob’s, and leads to the antipodes of heaven. It may seem a small thing to admit that the dull vital actions of a fungus, or a foraminifer, are the properties of their protoplasm, and are the direct results of the nature of the matter of which they are composed. But if, as I have endeavoured to prove to you, their protoplasm is essentially identical with, and most readily converted into, that of any animal, I can discover no logical halting-place between the admission that such is the case, and the further concession that all vital action may, with equal propriety, be said to be the result of the molecular forces of the protoplasm which displays it. And if so, it must be true, in the same sense and to the same extent, that the thoughts to which I am now giving utterance, and your thoughts regarding them, are the expression of molecular changes in that matter of life which is the source of our other vital phaenomena.[109]

ON CORAL AND CORAL REEFS [110]

The marine productions which are commonly known by the names of “Corals” and “Corallines,” were thought by the ancients to be sea- weeds, which had the singular property of becoming hard and solid, when they were fished up from their native depths and came into contact with the air.

“Sic et curalium, quo primum contigit auras Tempore durescit: mollis fuit herba sub undis,”[111]

says Ovid (Metam. xv); and it was not until the seventeenth century that Boccone [112] was emboldened, by personal experience of the facts, to declare that the holders of this belief were no better than “idiots,” who had been misled by the softness of the outer coat of the living red coral to imagine that it was soft all through.

Messer Boccone’s strong epithet is probably undeserved, as the notion he controverts, in all likelihood, arose merely from the misinterpretation of the strictly true statement which any coral fisherman would make to a curious inquirer; namely, that the outside coat of the red coral is quite soft when it is taken out of the sea. At any rate, he did good service by eliminating this much error from the current notions about coral. But the belief that corals are plants remained, not only in the popular, but in the scientific mind; and it received what appeared to be a striking confirmation from the researches of Marsigli [113] in 1706. For this naturalist, having the opportunity of observing freshly-taken red coral, saw that its branches were beset with what looked like delicate and beautiful flowers each having eight petals. It was true that these “flowers” could protrude and retract themselves, but their motions were hardly more extensive, or more varied, than those of the leaves of the sensitive plant; and therefore they could not be held to militate against the conclusion so strongly suggested by their form and their grouping upon the branches of a tree-like structure.

Twenty years later, a pupil of Marsigli, the young Marseilles physician, Peyssonel, conceived the desire to study these singular sea-plants, and was sent by the French Government on a mission to the Mediterranean for that purpose. The pupil undertook the investigation full of confidence in the ideas of his master, but being able to see and think for himself, he soon discovered that those ideas by no means altogether corresponded with reality. In an essay entitled “Traite du Corail,” which was communicated to the French Academy of Science, but which has never been published, Peyssonel writes:–

“Je fis fleurir le corail dans des vases pleins d’eau de mer, et j’observai que ce que nous croyons etre la fleur de cette pretendue plante n’etait au vrai, qu’un insecte semblable a une petite Ortie ou Poulpe. J’avais le plaisir de voir remuer les pattes, ou pieds, de cette Ortie, et ayant mis le vase plein d’eau ou le corail etait a une douce chaleur aupres du feu, tous les petits insectes s’epanouirent.–L’Ortie sortie etend les pieds, et forme ce que M. de Marsigli et moi avions pris pour les petales de la fleur. Le calice de cette pretendue fleur est le corps meme de l’animal avance et sorti hors de la cellule.”*[114]

* This extract from Peyssonel’s manuscript is given by M. Lacaze Duthiers in his valuable Histoire Naturelle du Corail (1866).

The comparison of the flowers of the coral to a “petite ortie,” or “little nettle,” is perfectly just, but needs explanation. “Ortie de mer,” or “sea-nettle,” is, in fact, the French appellation for our “sea-anemone,” a creature with which everybody, since the great aquarium mania, must have become familiar, even to the limits of boredom. In 1710, the great naturalist, Reaumur,[115] had written a memoir for the express purpose of demonstrating that these “orties” are animals; and with this important paper Peyssonel must necessarily have been familiar. Therefore, when he declared the “flowers” of the red coral to be little “orties,” it was the same thing as saying that they were animals of the same general nature as sea-anemones. But to Peyssonel’s contemporaries this was an extremely startling announcement. It was hard to imagine the existence of such a thing as an association of animals into a structure with stem and branches altogether like a plant, and fixed to the soil as a plant is fixed; and the naturalists of that day preferred not to imagine it. Even Reaumur could not bring himself to accept the notion, and France being blessed with Academicians, whose great function (as the late Bishop Wilson [116] and an eminent modern writer [117] have so well shown) is to cause sweetness and light to prevail, and to prevent such unmannerly fellows as Peyssonel from blurting out unedifying truths, they suppressed him; and, as aforesaid, his great work remained in manuscript, and may at this day be consulted by the curious in that state, in the Bibliotheque du Museum d’Histoire Naturelle. Peyssonel, who evidently was a person of savage and untameable disposition, so far from appreciating the kindness of the Academicians in giving him time to reflect upon the unreasonableness, not to say rudeness, of making public statements in opposition to the views of some of the most distinguished of their body, seems bitterly to have resented the treatment he met with. For he sent all further communications to the Royal Society of London, which never had, and it is to be hoped never will have, anything of an academic constitution; and finally he took himself off to Guadaloupe, and became lost to science altogether.

Fifteen or sixteen years after the date of Peyssonel’s suppressed paper, the Abbe Trembley [118] published his wonderful researches upon the fresh-water Hydra. Bernard de Jussieu [119] and Guettard [120] followed them up by like inquiries upon the marine sea-anemones and corallines; Reaumur, convinced against his will of the entire justice of Peyssonel’s views, adopted them, and made him a half-and-half apology in the preface to the next published volume of the “Memoires pour servir l’Histoire des Insectes;” and, from this time forth, Peyssonel’s doctrine that corals are the work of animal organisms has been part of the body of established scientific truth.

Peyssonel, in the extract from his memoir already cited, compares the flower-like animal of the coral to a “poulpe,” which is the French form of the name “polypus,”–“the many-footed,”–which the ancient naturalists gave to the soft-bodied cuttlefishes, which, like the coral animal, have eight arms, or tentacles, disposed around a central mouth. Reaumur, admitting the analogy indicated by Peyssonel, gave the name of polypes, not only to the sea- anemone, the coral animal, and the fresh-water Hydra, but to what are now known as the Polyzoa, and he termed the skeleton which they fabricate a “polypier,” or “polypidom.”

The progress of discovery, since Reaumur’s time, has made us very completely acquainted with the structure and habits of all these polypes. We know that, among the sea-anemones and coral-forming animals, each poylpe has a mouth leading to a stomach, which is open at its inner end, and thus communicates freely with the general cavity of the body; that the tentacles placed round the mouth are hollow, and that they perform the part of arms in seizing and capturing prey. It is known that many of these creatures are capable of being multiplied by artificial division, the divided halves growing, after a time, into complete and separate animals; and that many are able to perform a very similar process naturally, in such a manner that one polype may, by repeated incomplete divisions, give rise to a sort of sheet, or turf, formed by innumerable connected, and yet independent, descendants. Or, what is still more common, a polype may throw out buds, which are converted into polypes, or branches bearing polypes, until a tree- like mass, sometimes of very considerable size, is formed.

This is what happens in the case of the red coral of commerce. A minute polype, fixed to the rocky bottom of the deep sea, grows up into a branched trunk. The end of every branch and twig is terminated by a polype; and all the polypes are connected together by a fleshy substance, traversed by innumerable canals which place each polype in communication with every other, and carry nourishment to the substance of the supporting stem. It is a sort of natural cooperative store, every polype helping the whole, at the same time as it helps itself. The interior of the stem, like that of the branches, is solidified by the deposition of carbonate of lime in its tissue, somewhat in the same fashion as our own bones are formed of animal matter impregnated with lime salts; and it is this dense skeleton (usually turned red by a peculiar colouring matter) cleared of the soft animal investment, as the hard wood of a tree might be stripped of its bark, which is the red coral.

In the case of the red coral, the hard skeleton belongs to the interior of the stem and branches only; but in the commoner white corals, each polype has a complete skeleton of its own. These polypes are sometimes solitary, in which case the whole skeleton is represented by a single cup, with partitions radiating from its centre to its circumference. When the polypes formed by budding or division remain associated, the polypidom is sometimes made up of nothing but an aggregation of these cups, while at other times the cups are at once separated and held together, by an intermediate substance, which represents the branches of the red coral. The red coral polype again is a comparatively rare animal, inhabiting a limited area, the skeleton of which has but a very insignificant mass; while the white corals are very common, occur in almost all seas, and form skeletons which are sometimes extremely massive.

With a very few exceptions, both the red and the white coral polypes are, in their adult state, firmly adherent to the sea- bottom; nor do their buds naturally become detached and locomotive. But, in addition to budding and division, these creatures possess the more ordinary methods of multiplication; and, at particular seasons, they give rise to numerous eggs of minute size. Within these eggs the young are formed, and they leave the egg in a condition which has no sort of resemblance to the perfect animal. It is, in fact, a minute oval body, many hundred times smaller than the full grown creature, and it swims about with great activity by the help of multitudes of little hair-like filaments, called cilia, with which its body is covered. These cilia all lash the water in one direction, and so drive the little body along as if it were propelled by thousands of extremely minute paddles. After enjoying its freedom for a longer or shorter time, and being carried either by the force of its own cilia, or by currents which bear it along, the embryo coral settles down to the bottom, loses its cilia, and becomes fixed to the rock, gradually assuming the polype form and growing up to the size of its parent. As the infant polypes of the coral may retain this free and active condition for many hours, or even days, and as a tidal or other current in the sea may easily flow at the speed of two or even more miles in an hour, it is clear that the embryo must often be transported to very considerable distances from the parent. And it is easily understood how a single polype, which may give rise to hundreds, or perhaps thousands, of embryos, may, by this process of partly active and partly passive migration, cover an immense surface with its offspring.

The masses of coral which may be formed by the assemblages of polypes which spring by budding, or by dividing, from a single polype, occasionally attain very considerable dimensions. Such skeletons are sometimes great plates, many feet long and several feet in thickness; or they may form huge half globes, like the brainstone corals, or may reach the magnitude of stout shrubs or even small trees. There is reason to believe that such masses as these take a long time to form, and hence that the age a polype tree, or polype turf, may attain, may be considerable. But, sooner or later, the coral polypes, like all other things, die; the soft flesh decays, while the skeleton is left as a stony mass at the bottom of the sea, where it retains its integrity for a longer or a shorter time, according as its position affords more or less protection from the wear and tear of the waves.

The polypes which give rise to the white coral are found, as has been said, in the seas of all parts of the world; but in the temperate and cold oceans they are scattered and comparatively small in size, so that the skeletons of those which die do not accumulate in any considerable quantity. But it is otherwise in the greater part of the ocean which lies in the warmer parts of the world, comprised within a distance of about eighteen hundred miles on each side of the equator. Within the zone thus bounded, by far the greater part of the ocean is inhabited by coral polypes, which not only form very strong and large skeletons, but associate together into great masses, like the thickets and the meadow turf, or, better still, the accumulations of peat, to which plants give rise on dry land. These masses of stony matter, heaped up beneath the waters of the ocean, become as dangerous to mariners as so much ordinary rock, and to these, as to the common rock ridges, the seaman gives the name of “reefs.”

Such coral reefs cover many thousand square miles in the Pacific and in the Indian Oceans. There is one reef, or rather great series of reefs, called the Barrier Reef, which stretches, almost continuously, for more than eleven hundred miles off the east coast of Australia. Multitudes of the islands in the Pacific are either reefs themselves, or are surrounded by reefs. The Red Sea is in many parts almost a maze of such reefs, and they abound no less in the West Indies, along the coast of Florida, and even as far north as the Bahama Islands. But it is a very remarkable circumstance that, within the area of what we may call the “coral zone,” there are no coral reefs upon the west coast of America, nor upon the west coast of Africa; and it is a general fact that the reefs are interrupted, or absent, opposite the mouths of great rivers. The causes of this apparent caprice in the distribution of coral reefs are not far to seek. The polypes which fabricate them require for their vigorous growth a temperature which must not fall below 68 degrees Fahrenheit all the year round, and this temperature is only to be found within the distance on each side of the equator which has been mentioned, or thereabouts. But even within the coral zone this degree of warmth is not everywhere to be had. On the west coast of America, and on the corresponding coast of Africa, the currents of cold water from the icy regions which surround the South Pole set northward, and it appears to be due to their cooling influence that the sea in these regions is free from the reef builders. Again, the coral polypes cannot live in water which is rendered brackish by floods from the land, or which is perturbed by mud from the same source, and hence it is that they cease to exist opposite the mouths of rivers, which damage them in both these ways.

Such is the general distribution of the reef-building corals, but there are some very interesting and singular circumstances to be observed in the conformation of the reefs, when we consider them individually. The reefs, in fact, are of three different kinds; some of them stretch out from the shore, almost like a prolongation of the beach, covered only by shallow water, and in the case of an island, surrounding it like a fringe of no considerable breadth. These are termed “fringing reefs.” Others are separated by a channel which may attain a width of many miles, and a depth of twenty or thirty fathoms or more, from the nearest land; and when this land is an island, the reef surrounds it like a low wall, and the sea between the reef and the land is, as it were, a moat inside this wall. Such reefs as these are called “encircling” when they surround an island; and “barrier” reefs, when they stretch parallel with the coast of a continent. In both these cases there is ordinary dry land inside the reef, and separated from it only by a narrower or a wider, a shallower or a deeper, space of sea, which is called a “lagoon,” or “inner passage.” But there is a third kind of reef, of very common occurrence in the Pacific and Indian Oceans, which goes by the name of “atoll.” This is, to all intents and purposes, an encircling reef, without anything to encircle; or, in other words, without an island in the middle of its lagoon. The atoll has exactly the appearance of a vast, irregularly oval, or circular, breakwater, enclosing smooth water in its midst. The depth of the water in the lagoon rarely exceeds twenty or thirty fathoms, but, outside the reef, it deepens with great rapidity to two hundred or three hundred fathoms. The depth immediately outside the barrier, or encircling, reefs, may also be very considerable; but, at the outer edge of a fringing reef, it does not amount usually to more than twenty or twenty-five fathoms; in other words, from one hundred and twenty to one hundred and fifty feet.

Thus, if the water of the ocean should be suddenly drained away, we should see the atolls rising from the sea-bed like vast truncated cones, and resembling so many volcanic craters, except that their sides would be steeper than those of an ordinary volcano. In the case of the encircling reefs, the cone, with the enclosed island, would look like Vesuvius with Monte Nuovo within the old crater of Somma;[121] while, finally, the island with a fringing reef would have the appearance of an ordinary hill, or mountain, girded by a vast parapet, within which would lie a shallow moat. And the dry bed of the Pacific might afford grounds for an inhabitant of the moon to speculate upon the extraordinary subterranean activity to which these vast and numerous “craters” bore witness!

When the structure of a fringing reef is investigated, the bottom of the lagoon is found to be covered with fine whitish mud, which results from the breaking up of the dead corals. Upon this muddy floor there lie, here and there, growing corals, or occasionally great blocks of dead coral, which have been torn by storms from the outer edge of the reef, and washed into the lagoon. Shellfish and worms of various kinds abound; and fish, some of which prey upon the coral, sport in the deeper pools. But the corals which are to be seen growing in the shallow waters of the lagoon are of a different kind from those which abound on the outer edge of the reef, and of which the reef is built up. Close to the seaward edge of the reef, over which, even in calm weather, a surf almost always breaks, the coral rock is encrusted with a thick coat of a singular vegetable organism, which contains a great deal of lime–the so- called Nullipora. Beyond this, in the part of the edge of the reef which is always covered by the breaking waves, the living, true, reef-polypes make their appearance; and, in different forms, coat the steep seaward face of the reef to a depth of one hundred or even one hundred and fifty feet. Beyond this depth the sounding- lead rests, not upon the wall-like face of the reef, but on the ordinary shelving sea-bottom. And the distance to which a fringing reef extends from the land corresponds with that at which the sea has a depth of twenty or five-and-twenty fathoms.

If, as we have supposed, the sea could be suddenly withdrawn from around an island provided with a fringing reef, such as the Mauritius,[122] the reef would present the aspect of a terrace, its seaward face, one hundred feet or more high, blooming with the animal flowers of the coral, while its surface would be hollowed out into a shallow and irregular moat-like excavation.

The coral mud, which occupies the bottom of the lagoon, and with which all the interstices of the coral skeletons which accumulate to form the reef are filled up, does not proceed from the washing action of the waves alone; innumerable fishes, and other creatures which prey upon the coral, add a very important contribution of finely-triturated calcareous matter; and the corals and mud becoming incorporated together, gradually harden and give rise to a sort of limestone rock, which may vary a good deal in texture. Sometimes it remains friable and chalky, but, more often, the infiltration of water, charged with carbonic acid, dissolves some of the calcareous matter, and deposits it elsewhere in the interstices of the nascent rock, thus glueing and cementing the particles together into a hard mass; or it may even dissolve the carbonate of lime more extensively, and re-deposit it in a crystalline form. On the beach of the lagoon, where the coral sand is washed into layers by the action of the waves, its grains become thus fused together into strata of a limestone, so hard that they ring when struck with a hammer, and inclined at a gentle angle, corresponding with that of the surface of the beach. The hard parts of the many animals which live upon the reef become imbedded in this coral limestone, so that a block may be full of shells of bivalves and univalves, or of sea urchins; and even sometimes encloses the eggs of turtles in a state of petrification. The active and vigorous growth of the reef goes on only at the seaward margins, where the polypes are exposed to the wash of the surf, and are thereby provided with an abundant supply of air and of food. The interior portion of the reef may be regarded as almost wholly an accumulation of dead skeletons. Where a river comes down from the land there is a break in the reef, for the reasons which have been already mentioned.

The origin and mode of formation of a fringing reef, such as that just described, are plain enough. The embryos of the coral polypes have fixed themselves upon the submerged shore of the island, as far out as they could live, namely, to a depth of twenty or twenty- five fathoms. One generation has succeeded another, building itself up upon the dead skeletons of its predecessor. The mass has been consolidated by the infiltration of coral mud, and hardened by partial solution and redeposition, until a great rampart of coral rock one hundred or one hundred and fifty feet high on its seaward face has been formed all round the island, with only such gaps as result from the outflow of rivers, in the place of sally-ports.

The structure of the rocky accumulation in the encircling reefs and in the atolls is essentially the same as in the fringing reef. But, in addition to the differences of depth inside and out, they present some other peculiarities. These reefs, and especially the atolls, are usually interrupted at one part of their circumference, and this part is always situated on the leeward side of the reef, or that which is the more sheltered side. Now, as all these reefs are situated within the region in which the tradewinds prevail, it follows that, on the north side of the equator, where the trade- wind is a northeasterly wind, the opening of the reef is on the southwest side: while in the southern hemisphere, where the trade- winds blow from the southeast, the opening lies to the northwest. The curious practical result follows from this structure, that the lagoons to these reefs really form admirable harbours, if a ship can only get inside them. But the main difference between the encircling reefs and the atolls, on the one hand, and the fringing reefs on the other, lies in the fact of the much greater depth of water on the seaward faces of the former. As a consequence of this fact, the whole of this face is not, as it is in the case of the fringing reef, covered with living coral polypes. For, as we have seen, these polypes cannot live at a greater depth than about twenty-five fathoms; and actual observation has shown that while, down to this depth, the sounding-lead will bring up branches of live coral from the outer wall of such a reef, at a greater depth it fetches to the surface nothing but dead coral and coral sand. We must, therefore, picture to ourselves an atoll, or an encircling reef, as fringed for one hundred feet, or more, from its summit, with coral polypes busily engaged in fabricating coral; while, below this comparatively narrow belt, its surface is a bare and smooth expanse of coral sand, supported upon and within a core of coral limestone. Thus, if the bed of the Pacific were suddenly laid bare, as was just now supposed, the appearance of the reef- mountains would be exactly the reverse of that presented by many high mountains on land. For these are white with snow at the top, while their bases are clothed with an abundant and gaudily-coloured vegetation. But the coral cones would look grey and barren below, while their summits would be gay with a richly-coloured parterre of flowerlike coral polypes.

The practical difficulties of sounding upon, and of bringing up portions of, the seaward face of an atoll or of an encircling reef, are so great, in consequence of the constant and dangerous swell which sets towards it, that no exact information concerning the depth to which the reefs are composed of coral has yet been obtained. There is no reason to doubt, however, that the reef-cone has the same structure from its summit to its base, and that its sea-wall is throughout mainly composed of dead coral.

And now arises a serious difficulty. If the coral polypes cannot live at a greater depth than one hundred or one hundred and fifty feet, how can they have built up the base of the reef-cone, which may be two thousand feet, or more, below the surface of the sea?

In order to get over this objection, it was at one time supposed that the reef-building polypes had settled upon the summits of a chain of submarine mountains. But what is there in physical geography to justify the assumption of the existence of a chain of mountains stretching for one thousand miles or more, and so nearly of the same height, that none should rise above the level of the sea, nor fall one hundred and fifty feet below that level?

How, again, on this hypothesis, are atolls to be accounted for, unless, as some have done, we take refuge in the wild supposition that every atoll corresponds with the crater of a submarine volcano? And what explanation does it afford of the fact that, in some parts of the ocean, only atolls and encircling reefs occur, while others present none but fringing reefs?

These and other puzzling facts remained insoluble until the publication, in the year 1840, of Mr. Darwin’s famous work on coral reefs;[123] in which a key was given to all the difficult problems connected with the subject, and every difficulty was shown to be capable of solution by deductive reasoning from a happy combination of certain well-established geological and biological truths. Mr. Darwin, in fact, showed that, so long as the level of the sea remains unaltered in any area in which coral reefs are being formed, or if the level of the sea relatively to that of the land is falling, the only reefs which can be formed are fringing reefs. While if, on the contrary, the level of the sea is rising relatively to that of the land, at a rate not faster than that at which the upward growth of the coral can keep pace with it, the reef will gradually pass from the condition of a fringing, into that of an encircling or barrier reef. And, finally, that if the relative level of the sea rise so much that the encircled land is completely submerged, the reef must necessarily pass into the condition of an atoll.

For, suppose the relative level of the sea to remain stationary, after a fringing reef has reached that distance from the land at which the depth of water amounts to one hundred and fifty feet. Then the reef cannot extend seaward by the migration of coral germs, because these coral germs would find the bottom of the sea to be too deep for them to live in. And the only manner in which the reef could extend outwards, would be by the gradual accumulation, at the foot of its seaward face, of a talus of coral fragments torn off by the violence of the waves, which talus might, in course of time, become high enough to bring its upper surface within the limits of coral growth, and in that manner provide a sort of factitious sea-bottom upon which the coral embryos might perch. If, on the other hand, the level of the sea were slowly and gradually lowered, it is clear that the parts of its bottom originally beyond the limit of coral growth would gradually be brought within the required distance of the surface, and thus the reef might be indefinitely extended. But this process would give rise neither to an encircling reef nor to an atoll, but to a broad belt of upheaved coral rock, increasing the dimensions of the dry land, and continuous seawards with the fresh fringing reef.

Suppose, however, that the sea-level rose instead of falling, at the same slow and gradual rate at which we know it to be rising in some parts of the world,–not more, in fact, than a few inches, or, at most, a foot or two, in a hundred years. Then, while the reef would be unable to extend itself seaward, the sea-bottom outside it being gradually more and more removed from the depth at which the life of the coral polypes is possible, it would be able to grow upwards as fast as the sea rose. But the growth would take place almost exclusively around the circumference of the reef, this being the only region in which the coral polypes would find the conditions favourable for their existence. The bottom of the lagoon would be raised, in the main, only by the coral debris and coral mud, formed in the manner already described; consequently, the margins of the reef would rise faster than the bottom, or, in other words, the lagoon would constantly become deeper. And, at the same time, it would gradually increase in breadth; as the rising sea, covering more of the land, would occupy a wider space between the edge of the reef and what remained of the land. Thus the rising sea would eventually convert a large island with a fringing reef into a small island surrounded by an encircling reef. And it will be obvious that when the rising of the sea has gone so far as completely to cover the highest points of the island, the reef will have passed into the condition of an atoll.

But how is it possible that the relative level of the land and sea should be altered to this extent? Clearly, only in one of two ways: either the sea must have risen over those areas which are now covered by atolls and encircling reefs; or, the land upon which the sea rests must have been depressed to a corresponding extent.

If the sea has risen, its rise must have taken place over the whole world simultaneously, and it must have risen to the same height over all parts of the coral zone. Grounds have been shown for the belief that the general level of the sea may have been different at different times; it has been suggested, for example, that the accumulation of ice about the poles during one of the cold periods of the earth’s history necessarily implies a diminution in the volume of the sea proportioned to the amount of its water thus permanently locked up in the Arctic and Antarctic ice-cellars; while, in the warm periods, the greater or less disappearance of the polar ice-cap implies a corresponding addition of water to the ocean. And no doubt this reasoning must be admitted to be sound in principle; though it is very hard to say what practical effect the additions and subtractions thus made have had on the level of the ocean; inasmuch as such additions and subtractions might be either intensified or nullified, by contemporaneous changes in the level of the land. And no one has yet shown that any such great melting of polar ice, and consequent raising of the level of the water of the ocean, has taken place since the existing atolls began to be formed.

In the absence of any evidence that the sea has ever risen to the extent required to give rise to the encircling reefs and the atolls, Mr. Darwin adopted the opposite hypothesis, viz., that the land has undergone extensive and slow depression in those localities in which these structures exist.

It seems, at first, a startling paradox, to suppose that the land is less fixed than the sea; but that such is the case is the uniform testimony of geology. Beds of sandstone or limestone, thousands of feet thick, and all full of marine remains, occur in various parts of the earth’s surface, and prove, beyond a doubt, that when these beds were formed, that portion of the sea-bottom which they then occupied underwent a slow and gradual depression to a distance which cannot have been less than the thickness of those beds, and may have been very much greater. In supposing, therefore, that the great areas of the Pacific and of the Indian Ocean, over which atolls and encircling reefs are found scattered, have undergone a depression of some hundreds, or, it may be, thousands of feet, Mr. Darwin made a supposition which had nothing forced or improbable, but was entirely in accordance with what we know to have taken place over similarly extensive areas, in other periods of the world’s history. But Mr. Darwin subjected his hypothesis to an ingenious indirect test. If his view be correct, it is clear that neither atolls, nor encircling reefs, should be found in those portions of the ocean in which we have reason to believe, on independent grounds, that the sea-bottom has long been either stationary, or slowly rising. Now it is known that, as a general rule, the level of the land is either stationary, or is undergoing a slow upheaval, in the neighborhood of active volcanoes; and, therefore, neither atolls nor encircling reefs ought to be found in regions in which volcanoes are numerous and active. And this turns out to be the case. Appended to Mr. Darwin’s great work on coral reefs, there is a map on which atolls and encircling reefs are indicated by one colour, fringing reefs by another, and active volcanoes by a third. And it is at once obvious that the lines of active volcanoes lie around the margins of the areas occupied by the atolls and the encircling reefs. It is exactly as if the upheaving volcanic agencies had lifted up the edges of these great areas, while their centres had undergone a corresponding depression. An atoll area may, in short, be pictured as a kind of basin, the margins of which have been pushed up by the subterranean forces, to which the craters of the volcanoes have, at intervals, given vent.

Thus we must imagine the area of the Pacific now covered by the Polynesian Archipelago, as having been, at some former time, occupied by large islands, or, may be, by a great continent, with the ordinarily diversified surface of plain, and hill, and mountain chain. The shores of this great land were doubtless fringed by coral reefs; and, as it slowly underwent depression, the hilly regions, converted into islands, became, at first, surrounded by fringing reefs, and then, as depression went on, these became converted into encircling reefs, and these, finally, into atolls, until a maze of reefs and coral-girdled islets took the place of the original land masses.

Thus the atolls and the encircling reefs furnish us with clear, though indirect, evidence of changes in the physical geography of large parts of the earth’s surface; and even, as my lamented friend, the late Professor Jukes,[124] has suggested, give us indications of the manner in which some of the most puzzling facts connected with the distribution of animals have been brought about. For example, Australia and New Guinea are separated by Torres Straits, a broad belt of sea one hundred or one hundred and twenty miles wide. Nevertheless, there is in many respects a curious resemblance between the land animals which inhabit New Guinea and the land animals which inhabit Australia. But, at the same time, the marine shellfish which are found in the shallow waters of the shores of New Guinea are quite different from those which are met with upon the coasts of Australia. Now, the eastern end of Torres Straits is full of atolls, which, in fact, form the northern termination of the Great Barrier Reef which skirts the eastern coast of Australia. It follows, therefore, that the eastern end of Torres Straits is an area of depression, and it is very possible, and on many grounds highly probable, that, in former times, Australia and New Guinea were directly connected together, and that Torres Straits did not exist. If this were the case, the existence of cassowaries and of marsupial quadrupeds, both in New Guinea and in Australia, becomes intelligible; while the difference between the littoral molluscs of the north and the south shores of Torres Straits is readily explained by the great probability that, when the depression in question took place, and what was, at first, an arm of the sea became converted into a strait separating Australia from New Guinea, the northern shore of this new sea became tenanted with marine animals from the north, while the southern shore was peopled by immigrants from the already existing marine Australian fauna.

Inasmuch as the growth of the reef depends upon that of successive generations of coral polypes, and as each generation takes a certain time to grow to its full size, and can only separate its calcareous skeleton from the water in which it lives at a certain rate, it is clear that the reefs are records not only of changes in physical geography, but of the lapse of time. It is by no means easy, however, to estimate the exact value of reef chronology, and the attempts which have been made to determine the rate at which a reef grows vertically have yielded anything but precise results. A cautious writer, Mr. Dana,[125] whose extensive study of corals and coral reefs makes him an eminently competent judge, states his conclusion in the following terms:–

“The rate of growth of the common branching madrepore is not over one and a half inches a year. As the branches are open, this would not be equivalent to more than half an inch in height of solid coral for the whole surface covered by the madrepore; and, as they are also porous, to not over three-eighths of an inch of solid limestone. But a coral plantation has large bare patches without corals, and the coral sands are widely distributed by currents, part of them to depths over one hundred feet where there are no living corals; not more than one-sixth of the surface of a reef region is, in fact, covered with growing species. This reduces the three-eighths to ONE-SIXTEENTH. Shells and other organic relics may contribute one-fourth as much as corals. At the outside, the average upward increase of the whole reef-ground per year would not exceed ONE-EIGHTH of an inch.

“Now some reefs are at least two thousand feet thick, which at one- eighth of an inch a year, corresponds to one hundred and ninety-two thousand years.”*

* Dana, Manual of Geology, p. 591.

Halve, or quarter, this estimate if you will, in order to be certain of erring upon the right side, and still there remains a prodigious period during which the ancestors of existing coral polypes have been undisturbedly at work; and during which, therefore, the climatal conditions over the coral area must have been much what they are now.

And all this lapse of time has occurred within the most recent period of the history of the earth. The remains of reefs formed by coral polypes of different kinds from those which exist now, enter largely into the composition of the limestones of the Jurassic period;[126] and still more widely different coral polypes have contributed their quota to the vast thickness of the carboniferous and Devonian strata. Then as regards the latter group of rocks in America, the high authority already quoted tells us:–

“The Upper Helderberg period is eminently the coral reef period of the palaeozoic ages. Many of the rocks abound in coral, and are as truly coral reefs as the modern reefs of the Pacific. The corals are sometimes standing on the rocks in the position they had when growing: others are lying in fragments, as they were broken and heaped by the waves; and others were reduced to a compact limestone by the finer trituration before consolidation into rock. This compact variety is the most common kind among the coral reef rocks of the present seas; and it often contains but few distinct fossils, although formed in water that abounded in life. At the fall of the Ohio, near Louisville, there is a magnificent display of the old reef. Hemispherical Favosites, five or six feet in diameter, lie there nearly as perfect as when they were covered by their flowerlike polypes; and besides these, there are various branching corals, and a profusion of Cyathophyllia, or cup- corals.”*

* Dana, Manual of Geology, p. 272.

Thus, in all the great periods of the earth’s history of which we know anything, a part of the then living matter has had the form of polypes, competent to separate from the water of the sea the carbonate of lime necessary for their own skeletons. Grain by grain, and particle by particle, they have built up vast masses of rock, the thickness of which is measured by hundreds of feet, and their area by thousands of square miles. The slow oscillations of the crust of the earth, producing great changes in the distribution of land and water, have often obliged the living matter of the coral-builders to shift the locality of its operations; and, by variation and adaptation to these modifications of condition, its forms have as often changed. The work it has done in the past is, for the most part, swept away, but fragments remain, and, if there were no other evidence, suffice to prove the general constancy of the operations of Nature in this world, through periods of almost inconceivable duration.

NOTES

AUTOBIOGRAPHY

[1]
Autobiography: Huxley’s account of this sketch, written in 1889, is as follows: “A man who is bringing out a series of portraits of celebrities, with a sketch of their career attached, has bothered me out of my life for something to go with my portrait, and to escape the abominable bad taste of some of the notices, I have done that.”

[2]
pre-Boswellian epoch: the time before Boswell. James Boswell (1740-1795) wrote the famous Life of Samuel Johnson. Mr. Leslie Stephen declares that this book “became the first specimen of a new literary type.” “It is a full-length portrait of a man’s domestic life with enough picturesque detail to enable us to see him through the eyes of private friendship. . . .” A number of biographers since Boswell have imitated his method; and Leslie Stephen believes that “we owe it in some degree to his example that we have such delightful books as Lockhart’s Life of Scott or Mr. Trevelyan’s Life of Macaulay.”

[3]
“Bene qui latuit, bene vixit”: from Ovid. He who has kept himself well hidden, has lived well.

[4]
Prince George of Cambridge: the grandson of King George III, second Duke of Cambridge, and Commander-in-chief of the British Army.

[5]
Mr. Herbert Spencer (1820–1903): a celebrated English philosopher and powerful advocate of the doctrine of evolution. Spencer is regarded as one of the most profound thinkers of modern times. He was one of Huxley’s closest friends.

[6]
in partibus infidelium: in the domain of the unbelievers.

[7]
“sweet south upon a bed of violets.” Cf. Twelfth Night, Act I, sc. I, l. 5.

O, it came o’er my ear like the sweet sound That breathes upon a bank of violets,
Stealing and giving odour.

For the reading “sweet south” instead of “sweet sound,” see Rolfe’s edition of Twelfth Night.

[8]
“Lehrjahre”: apprenticeship.

Charing Cross School of Medicine: a school connected with the Charing Cross Hospital in the Strand, London.

[9]
Nelson: Horatio Nelson, a celebrated English Admiral born in Norfolk, England, 1758, and died on board the Victory at Trafalgar, 1805. It was before the battle off Cape Trafalgar that Nelson hoisted his famous signal, “England expects every man will do his duty.” Cf. Tennyson’s Ode to the Duke of Wellington, stanza VI, for a famous tribute to Nelson.

[10]
middies: abbreviated form for midshipmen.

[11]
Suites a Buffon: sequels to Buffon. Buffon (1707-1781) was a French naturalist who wrote many volumes on science.

[12]
Linnean Society: a scientific society formed in 1788 under the auspices of several fellows of the Royal Society.

[13]
Royal Society: The Royal Society for Improving Natural Knowledge; the oldest scientific society in Great Britain, and one of the oldest in Europe. It was founded by Charles II, in 1660, its nucleus being an association of learned men already in existence. It is supposed to be identical with the Invisible College which Boyle mentions in 1646. It was incorporated under the name of The Royal Society in 1661. The publications of the Royal Society are called Philosophical Transactions. The society has close connection with the government, and has assisted the government in various important scientific undertakings among which may be mentioned Parry’s North Pole expedition. The society also distributes $20,000 yearly for the promotion of scientific research.

[14]
Rastignac: a character in Le Pere Goriot. At the close of the story Rastignac says, “A nous deux, maintenant”:–Henceforth there is war between us.

[15]
Pere Goriot: a novel of Balzac’s with a plot similar to King Lear.

[16]
Professor Tyndall (1820-1893): a distinguished British physicist and member of the Royal Society. He explored with Huxley the glaciers of Switzerland. His work in electricity, radiant heat, light and acoustics gave him a foremost place in science.

[17]
Ecclesiastical spirit: the spirit manifested by the clergy of England in Huxley’s time against the truths of science. The clergy considered scientific truth to be disastrous to religious truth. Huxley’s attitude toward the teaching of religious truth is illuminated by this quotation, which he uses to explain his own position: “I have the fullest confidence that in the reading and explaining of the Bible, what the children will be taught will be the great truths of Christian Life and conduct, which all of us desire they should know, and that no effort will be made to cram into their poor little minds, theological dogmas which their tender age prevents them from understanding.” Huxley defines his idea of a church as a place in which, “week by week, services should be devoted, not to the iteration of abstract propositions in theology, but to the setting before men’s minds of an ideal of true, just and pure living; a place in which those who are weary of the burden of daily cares should find a moment’s rest in the contemplation of the higher life which is possible for all, though attained by so few; a place in which the man of strife and of business should have time to think how small, after all, are the rewards he covets compared with peace and charity.”

[18]
New Reformation: Huxley writes: “We are in the midst of a gigantic movement greater than that which preceded and produced the Reformation, and really only the continuation of that movement. . . . But this organization will be the work of generations of men, and those who further it most will be those who teach men to rest in no lie, and to rest in no verbal delusion.”

ON THE ADVISABLENESS OF IMPROVING NATURAL KNOWLEDGE (1866)

[19]
On the Advisableness of Improving Natural Knowledge: from Method and Results: also published in Lay Sermons, Addresses and Reviews.

For the history of the times mentioned in this essay, see Green’s Short History of the English People.

[20]
The very spot: St. Martin’s Borough Hall and Public Library, on Charing Cross Road, near Trafalgar Square.

[21]
Defoe (1661-1731): an English novelist and political writer. On account of his political writings Defoe was sentenced to stand in the pillory, and to be “imprisoned during the Queen’s pleasure.” During this imprisonment he wrote many articles. Later in life he wrote Robinson Crusoe, The Fortunes and Misfortunes of Moll Flanders, Journal of the Plague Year, and other books less well known.

[22]
unholy cursing and crackling wit of the Rochesters and Sedleys: John Wilmot, the second Earl of Rochester, and Sir Charles Sedley, were both friends of Charles II, and were noted for biting wit and profligacy. Green, in his Short History of the English People, thus describes them: “Lord Rochester was a fashionable poet, and the titles of some of his poems are such as no pen of our day could copy. Sir Charles Sedley was a fashionable wit, and the foulness of his words made even the porters in the Covent Garden belt him from the balcony when he ventured to address them.”

[23]
Laud: Archbishop of Canterbury. Laud was born in 1573, and beheaded at London in 1645. He was throughout the reign of Charles I a staunch supporter of the King. He was impeached by the Long Parliament in 1640 and executed on Tower Hill, in 1645.

[24]
selenography: the scientific study of the moon with special reference to its physical condition.

[25]
Torricellian experiment: a reference to the discovery of the principle of the barometer by the Italian, Torricelli, in 1643.

[26]
Sir Francis Bacon (1561-1626): Bacon endeavored to teach that civilization cannot be brought to a high point except as man applies himself to the study of the secrets of nature, and uses these discoveries for inventions which will give him power over his environment. The chief value of the work was that it called attention to the uses of induction and to the experimental study of facts. See Roger’s A Student’s History of Philosophy, page 243.

[27]
The learned Dr. Wallis (1616-1703): Dr. Wallis is regarded as the greatest of Newton’s predecessors in mathematical history. His works are numerous and are on a great variety of subjects. He was one of the first members of the Royal Society.

[28]
“New Philosophy”: Bacon’s ideas on science and philosophy as set forth in his works.

[29]
Royal Society: see note, page 11.

[30]
Newton, Sir Isaac (1642-1721): a distinguished natural philosopher of England. Newton was elected a member of the Royal Society in 1672. His most important scientific accomplishment was the establishing of the law of universal gravitation. The story of the fall of the apple was first related by Voltaire to whom it was given by Newton’s niece.

[31]
“Philosophical Transactions”: the publications of the Royal Society.

[32]
Galileo (1564-1642): a famous Italian astronomer. His most noted work was the construction of the thermometer and a telescope. He discovered the satellites of Jupiter in 1610. In 1610, also, he observed the sun’s spots. His views were condemned by the Pope in 1616 and in 1633 he was forced by the Inquisition to abjure the Copernican theory.

[33]
Vesalius (1514-1564): a noted Belgian anatomist.

[34]
Harvey (1578-1657): an English physiologist and anatomist. He is noted especially for his discovery of the circulation of the blood.

[35]
Subtle speculations: Selby gives examples from questions discussed by Thomas Aquinas. Whether all angels belong to the same genus, whether demons are evil by nature, or by will, whether they can change one substance into another, . . . whether an angel can move from one point to another without passing through intermediate space.

[36]
Schoolmen: a term used to designate the followers of scholasticism, a philosophy of dogmatic religion which assumed a certain subject- matter as absolute and unquestionable. The duty of the Schoolman was to explain church doctrine; these explanations were characterized by fine distinctions and by an absence of real content. See Roger’s A Student’s History of Philosophy; also Baldwin’s Dictionary of Philosophy and Psychology.

[37]
“writ in water”: an allusion to Keats’ request that the words “Here lies one whose name was writ in water” be his epitaph. The words are inscribed on his tomb in the Protestant Cemetery at Rome.

[38]
Lord Brouncker: The first president of the Royal Society after its incorporation in 1662 was Lord Brouneker.

[39]
revenant: ghost.

[40]
Boyle: Robert Boyle (1627-1691): a British chemist and natural philosopher who was noted especially for his discovery of Boyle’s law of the elasticity of air.

[41]
Evelyn (1620-1706): an English author and member of the Royal Society. His most important work is the Diary, valuable for the full account which it gives of the manners and customs of the time.

[42]
The Restoration: In English history the re-establishing of the English monarchy with the return of King Charles II in 1660; by extension the whole reign of Charles II: as, the dramatists of the Restoration. Century Dictionary.

[43]
Aladdin’s lamps: a reference to the story of the Wonderful Lamp in the Arabian Nights. The magic lamp brought marvelous good fortune to the poor widow’s son who possessed it. Cf. also Lowell’s Aladdin:–

When I was a beggarly boy,
And lived in a cellar damp,
I had not a friend or a toy,
But I had Aladdin’s lamp;
When I could not sleep for the cold, I had fire enough in my brain,
And builded, with roofs of gold,
My beautiful castles in Spain!

[44]
“When in heaven the stars”: from Tennyson’s Specimens of a Translation of the Iliad in Blank Verse.

[45]
“increasing God’s honour and bettering man’s estate”: Bacon’s statement of his purpose in writing the Advancement of Learning.

[46]
For example, etc.: could the sentence beginning thus be written in better form?

[47]
Rumford (1738-1814): Benjamin Thompson, Count Rumford, an eminent scientist. Rumford was born in America and educated at Harvard. Suspected of loyalty to the King at the time of the revolution, he was imprisoned. Acquitted, he went to England where he became prominent in politics and science. Invested with the title of Count by the Holy Roman Empire, he chose Rumford for his title after the name of the little New Hampshire town where he had taught. He gave a large sum of money to Harvard College to found the Rumford professorship of science.

[48]
eccentric: out of the centre.

A LIBERAL EDUCATION (1868)

[49]
A Liberal Education: from Science and Education; also published in Lay Sermons, Addresses and Reviews.

[50]
Ichabod: cf. 1 Sam. iv, 21.

[51]
senior wranglership: in Cambridge University, England, one who has attained the first class in the elementary division of the public examination for honors in pure and mixed mathematics, commonly called the mathematical tripos, those who compose the second rank of honors being designated senior optimes, and those of the third order junior optimes. The student taking absolutely the first place in the mathematical tripos used to be called senior wrangler, those following next in the same division being respectively termed second, third, fourth, etc., wranglers. Century Dictionary.

[52]
double-first: any candidate for the degree of Bachelor of Arts in Oxford University who takes first-class honors in both classics and mathematics is said to have won a double-first.

[53]
Retzsch (1779-1857): a well-known German painter and engraver.

[54]
Test-Act: an English statute of 1673. It compelled all persons holding office under the crown to take the oaths of supremacy and of allegiance, to receive the sacrament according to the usage of the Church of England, and to subscribe to the Declaration against Transubstantiation.

[55]
Poll: an abbreviation and transliteration of [Greek words], “the mob”; university slang for the whole body of students taking merely the degree of Bachelor of Arts, at Cambridge.

[56]
pluck: the rejection of a student, after examinations, who does not come up to the standard.

ON A PIECE OF CHALK

[57]
On a Piece of Chalk: a lecture to working-men from Lay Sermons, Addresses and Reviews.

[58]
Needles of the Isle of Wight: the needles are three white, pointed rocks of chalk, resting on dark-colored bases, and rising abruptly from the sea to a height of 100 feet. Baedeker’s Great Britain.

[59]
Lulworth in Dorset, to Flamborough Head: Lulworth is on the southern coast of England, west of the Isle of Wight: Flamborough Head is on the northeastern coast of England and extends into the German Ocean.

[60]
Weald: a name given to an oval-shaped chalk area in England, beginning near the Straits of Dover, and extending into the counties of Kent, Surrey, Hants, and Sussex.

[61]
Lieut. Brooke: Brooke devised an apparatus for deep-sea sounding from which the weight necessary to sink the instrument rapidly, was detached when it reached the bottom. The object was to relieve the strain on the rope caused by rapid soundings. Improved apparatuses have been invented since the time of Brooke.

[62]
Ehrenberg (1795-1876): a German naturalist noted for his studies of Infusoria.

[63]
Bailey of West Point (1811-1857): an American naturalist noted for his researches in microscopy.

[64]
enterprise of laying down the telegraph-cable: the first Atlantic telegraph-cable between England and America was laid in 1858 by Cyrus W. Field of New York. Messages were sent over it for a few weeks; then it ceased to act. A permanent cable was laid by Mr. Field in 1866.

[65]
Dr. Wallich (1786-1854): a Danish botanist and member of the Royal Society.

[66]
Mr. Sorby: President of the Geological Society of England, and author of many papers on subjects connected with physical geography.

[67]
Sir Charles Lyell (1797-1875): a British geologist, and one of the first to uphold Darwin’s Origin of Species.

[68]
Echinus: the sea-urchin; an animal which dwells in a spheroidal shell built up from polygonal plates, and covered with sharp spines.

[69]
Somme: a river of northern France which flows into the English Channel northeast of Dieppe.

[70]
the chipped flints of Hoxne and Amiens: the rude instruments which were made by primitive man were of chipped flint. Numerous discoveries of large flint implements have been made in the north of France, near Amiens, and in England. The first noted flint implements were discovered in Hoxne, Suffolk, England, 1797. Cf. Evans’ Ancient Stone Implements and Lyell’s Antiquity of Man.

[71]
Rev. Mr. Gunn (1800-1881): an English naturalist. Mr. Gunn sent from Tasmania a large number of plants and animals now in the British Museum.

[72]
“the whirligig of time”: cf. Shakespeare, Twelfth Night, Act V, se. I, l. 395.

[73]
Euphrates and Hiddekel: cf. Genesis ii, 14.

[74]
the great river, the river of Babylon: cf. Genesis xv, 18

[75]
Without haste, but without rest: from Goethe’s Zahme Xenien. In a letter to his sister, Huxley says: “And then perhaps by the following of my favorite motto,–

“‘Wie das Gestirn,
Ohne Hast,
Ohne Rast’–

something may be done, and some of Sister Lizzie’s fond imaginations turn out not altogether untrue.” The quotation entire is as follows:–

Wie das Gestirn,
Ohne Hast,
Aber ohne Rast,
Drehe sich jeder
Um die eigne Last.

THE PRINCIPAL SUBJECTS OF EDUCATION (1882)

[76]
The Principal Subjects of Education: an extract from the essay, Science and Art in Relation to Education.

[77]
this discussion: “this” refers to the last sentence in the preceding paragraph, in which Huxley says that it will be impossible to determine the amount of time to be given to the principal subjects of education until it is determined “what the principal subjects of education ought to be.”

[78]
Francis Bacon: cf. note [26].

[79]
the best chance of being happy: In connection with Huxley’s work on the London School Board, his biographer says that Huxley did not regard “intellectual training only from the utilitarian point of view; he insisted, e. g., on the value of reading for amusement as one of the most valuable uses to hardworked people.”

[80]
“Harmony in grey”: cf. with l. 34 in Browning’s Andrea del Sarto.

[81]
Hobbes (1588-1679): noted for his views of human nature and of politics. According to Minto, “The merits ascribed to his style are brevity, simplicity and precision.”

[82]
Bishop Berkeley (1685-1753): an Irish prelate noted for his philosophical writings and especially for his theory of vision which was the foundation for modern investigations of the subject. “His style has always been esteemed admirable; simple, felicitous and sweetly melodious. His dialogues are sustained with great skill.” Minto’s Manual of English Prose Literature.

[83]
We have been recently furnished with in prose: The Iliad of Homer translated by Lang, Leaf and Myers, the first edition of which appeared in 1882, is probably the one to which Huxley refers. The Odyssey, translated by Butcher and Lang, appeared in 1879. Among the best of the more recent translations of Homer are the Odyssey by George Herbert Palmer; the Iliad by Arthur S. Way, and the Odyssey by the same author.

[84]
Locke (1632-1704): an English philosopher of great influence. His chief work is An Essay Concerning Human Understanding.

[85]
Franciscus Bacon sic cogitavit: thus Francis Bacon thought.

THE METHOD OF SCIENTIFIC INVESTIGATION (1863)

[86]
The Method of Scientific Investigation is an extract from the third of six lectures given to workingmen on The Causes of the Phenomena of Organic Nature in Darwiniana.

[87]
these terrible apparatus: apparatus is the form for both the singular and plural; apparatuses is another form for the plural.

[88]
Incident in one of Moliere’s plays: the allusion is to the hero, M. Jourdain in the play, “La Bourgeois Gentilbomme.”

[89]
these kind: modern writers regard kind as singular. Shakespeare treated it as a plural noun, as “These kind of knaves I knew.”

[90]
Newton: cf. [30].

[91]
Laplace (1749-1827): a celebrated French astronomer and mathematician. He is best known for his theory of the formation of the planetary systems, the so-called “nebular hypothesis.” Until recently this hypothesis has generally been accepted in its main outlines. It is now being supplanted by the “Spiral Nebular Hypothesis” developed by Professors Moulton and Chamberlin of the University of Chicago. See Moulton’s Introduction to Astronomy, p. 463.

ON THE PHYSICAL BASIS OF LIFE (1868)

[92]
On the Physical Basis of Life: from Methods and Results; also published in Lay Sermons, Addresses and Reviews. “The substance of this paper was contained in a discourse which was delivered in Edinburgh on the evening of Sunday, the 8th of November, 1868– being the first of a series of Sunday evening addresses upon non- theological topics, instituted by the Rev. J. Cranbrook. Some phrases, which could possess only a transitory and local interest, have been omitted; instead of the newspaper report of the Archbishop of York’s address, his Grace’s subsequently published pamphlet On the Limits of Philosophical inquiry is quoted, and I have, here and there, endeavoured to express my meaning more fully and clearly than I seem to have done in speaking–if I may judge by sundry criticisms upon what I am supposed to have said, which have appeared. But in substance, and, so far as my recollection serves, in form, what is here written corresponds with what was there said.”–Huxley.

[93]
Finner whale: a name given to a whale which has a dorsal fin. A Finner whale commonly measures from 60 to 90 feet in length.

[94]
A fortiori: with stronger reason: still more conclusively.

[95]
well-known epigram: from Goethe’s Venetianische Epigramme. The following is a translation of the passage: Why do the people push each other and shout? They want to work for their living, bring forth children; and feed them as well as they possibly can. . . . No man can attain to more, however much he may pretend to the contrary.

[96]
Maelstroms: a celebrated whirlpool or violent current in the Arctic Ocean, near the western coast of Norway, between the islands of Moskenaso and Mosken, formerly supposed to suck in and destroy everything that approached it at any time, but now known not to be dangerous except under certain conditions. Century Dictionary. Cf. also Poe’s Descent into the Maelstrom.

[97]
Milne-Edwards (1800-1885): a French naturalist. His Elements de Zoologie won him a great reputation.

[98]
with such qualifications as arises: a typographical error.

[99]
De Bary (1831-1888): a German botanist noted especially for his researches in cryptogamic botany.

[100]
No Man’s Land: Huxley probably intends no specific geographical reference. The expression is common as a designation of some remote and unfrequented locality.

[101]
Kuhne (1837-1900): a German physiologist and professor of science at Amsterdam and Heidelberg.

[102]
Debemur morti nos nostraque: Horace–Ars Poetica, line 63.

As forests change their foliage year by year, Leaves, that come first, first tall and disappear; So antique words die out, and in their room, Others spring up, of vigorous growth and bloom; Ourselves and all that’s ours, to death are due, And why should words not be mortal too?

Martin’s translation.

[103]
peau de chagrin: skin of a wild ass.

[104]
Balzac (1799-1850): a celebrated French novelist of the realistic school of fiction.

[105]
Barmecide feast: the allusion is to a story in the Arabian Nights in which a member of the Barmecide family places a succession of empty dishes before a beggar, pretending that they contain a rich repast.

[106]
modus operandi: method of working.

[107]
Martinus Scriblerus: a reference to Memoirs of Martinus Scriblerus written principally by John Arbuthnot, and published in 1741. The purpose of the papers is given by Warburton and Spence in the following extracts quoted from the Preface to the Memoirs of the Extraordinary Life, Works and Discoveries of Martinus Scriblerus in Elwin and Courthope’s edition of Pope’s works, vol. x, p. 273:–

“Mr. Pope, Dr. Arbuthnot, and Dr. Swift, in conjunction, formed the project of a satire on the abuses of human learning; and to make it better received, proposed to execute it in the manner of Cervantes (the original author of this species of satire) under a continued narrative of feigned adventures. They had observed that those abuses still kept their ground against all that the ablest and gravest authors could say to discredit them; they concluded, therefore, the force of ridicule was wanting to quicken their disgrace; and ridicule was here in its place, when the abuses had been already detected by sober reasoning; and truth in no danger to suffer by the premature use of so powerful an instrument.”

“The design of this work, as stated by Pope himself, is to ridicule all the false tastes in learning under the character of a man of capacity enough, that had dipped into every art and science, but injudiciously in each. It was begun by a club of some of the greatest wits of the age–Lord Oxford, the Bishop of Rochester, Pope, Congreve, Swift, Arbuthnot, and others. Gay often held the pen; and Addison liked it very well, and was not disinclined to come into it.”

[108]
accounted for the operation of the meat-jack: from the paper “To the learned inquisitor into nature, Martinus Scriblerus: the society of free thinkers greeting.” Elwin and Courthope, Pope’s works, vol. ?, p. 332.

[109]
The remainder of the essay endeavors to meet the charge of materialism. The following is the conclusion:–

“In itself it is of little moment whether we express the phaenomena of matter in terms of spirit; or the phaenomena of spirit in terms of matter: matter may be regarded as a form of thought, thought may be regarded as a property of matter–each statement has a certain relative truth. But with a view to the progress of science, the materialistic terminology is in every way to be preferred. For it connects thought with the other phaenomena of the universe, and suggests inquiry into the nature of those physical conditions, or concomitants of thought, which are more or less accessible to us, and a knowledge of which may, in future, help us to exercise the same kind of control over the world of thought, as we already possess in respect of the material world; whereas, the alternative, or spiritualistic, terminology is utterly barren, and leads to nothing but obscurity and confusion of ideas.

“Thus there can be little doubt, that the further science advances, the more extensively and consistently will all the phaenomena of Nature be represented by materialistic formulae and symbols. But the man of science, who, forgetting the limits of philosophical inquiry, slides from these formulae and symbols into what is commonly understood by materialism, seems to me to place himself on a level with the mathematician, who should mistake the x’s and y’s with which he works his problems, for real entities–and with this further disadvantage, as compared with the mathematician, that the blunders of the latter are of no practical consequence, while the errors of systematic materialism may paralyze the energies and destroy the beauty of a life.”

ON CORAL AND CORAL REEFS (1870)

[110]
On Coral and Coral Reefs: from Critiques and Addresses. The essay was published in 1870.

[111]
Sic et curalium: Thus also the coral, as soon as it touches the air turns hard. It was a soft plant under the water.

[112]
Boccone (1633-1704): a noted Sicilian naturalist.

[113]
Marsigli (1658-1730): an Italian soldier and naturalist. He wrote A Physical History of the Sea.

[114]
“Traite du Corail”: “I made the coral bloom in vases full of sea- water, and I noticed that what we believe to be the flower of this so-called plant was in reality only an insect similar to a little nettle or polype. I had the pleasure to see the paws or feet of this nettle move, and having placed the vase full of water in which the coral was, near the fire, at a moderate heat, all the little insects expanded, the nettle stretched out its feet and formed what M. de Marsigli and I had taken for the petals of the flower. The calyx of this so-called flower is the very body of the animal issued from its cell.”

[115]
Reaumur (1683-1757): a French physiologist and naturalist, best known as the inventor of the Reaumur thermometer. He was a member of the French Academy of Science.

[116]
Bishop Wilson: Thomas Wilson (1663-1755), bishop of the Isle of Man. Details of his life are given in the folio edition of his works (1782). An appreciation of his religious writings is given by Matthew Arnold in Culture and Anarchy. Bishop Wilson’s words, “To make reason and the will of God prevail,” are the theme of Arnold’s essay, Sweetness and Light.

[117]
An eminent modern writer: Matthew Arnold (1822-1888), eldest son of Thomas Arnold, headmaster of Rugby; a distinguished critic and poet, and professor of poetry at Oxford. The allusion is to Arnold’s essay, Sweetness and Light. The phrase, “sweetness and light,” is one which Aesop uses in Swift’s Battle of the Books to sum up the superiority of the ancients over the moderns. “As for us, the ancients, we are content, with the bee, to pretend to nothing of our own beyond our wings and our voice, that is to say, our flights and our language; for the rest, whatever we have got has been by infinite labor and search, and ranging through every corner of nature; the difference is, that instead of dirt and poison we have rather chose to fill our hives with honey and wax, thus furnishing mankind with the two noblest things, which are sweetness and light.” Arnold’s purpose in the essay is to define the cultured man as one who endeavors to make beauty and intelligence prevail everywhere.

[118]
Abbe Trembley (1700-1784): a Swiss naturalist. He wrote “Memoires pour servir a l’histoire d’un genre de polypes d’eau douce, a bras en forme de cornes.”

[119]
Bernard de Jussieu (1699-1776): a French botanist; founder of the natural classification of plants. He was superintendent of the Trianon Gardens.

[120]
Guettard (1715-1786): a French naturalist.

[121]
Monte Nuovo within the old crater of Somma: Monte Nuovo, a mountain west of Naples; Somma, a mountain north of Vesuvius which with its lofty, semicircular cliff encircles the active cone of Vesuvius.

[122]
Mauritius: an island in the Indian Ocean; Huxley visited the island when on the voyage with the Rattlesnake. He wrote to his mother of his visit: “This island is, you know, the scene of Saint Pierre’s beautiful story of Paul and Virginia, over which I suppose most people have sentimentalized at one time or another of their lives. Until we reached here I did not know that the tale was like the lady’s improver–a fiction founded on fact, and that Paul and Virginia were at one time flesh and blood, and that their veritable dust was buried at Pamplemousses in a spot considered as one of the lions of the place, and visited as classic ground.”

[123]
Mr. Darwin’s coral reefs: The Structure and Distribution of Coral Reefs, published in 1848.

[124]
Professor Jukes (1811-1869): an English geologist.

[125]
Mr. Dana (1813-1895): a well-known American geologist and mineralogist; a professor at Yale from 1845. He wrote a number of books among which is Coral and Coral Reefs.

[126]
Jurassic period: that part of the geological series which is older than the Cretaceous and newer than the Triassic; so called from the predominance of rocks of this age in the Jura Mountains. The three great divisions of fossiliferous rocks are called the Triassic, the Jurassic, and the Cretaceous.

REFERENCE BOOKS

The following reference books are suggested for a more complete treatment of various points in the text:–

Andrews’ History of England.
Green’s Short History of the English People. Traill’s Social England.
Roger’s A Student’s History of Philosophy. Royce’s The Spirit of Modern Philosophy. Huxley’s Life and Letters.
Smalley’s Mr. Huxley, in Scribner’s Magazine for October, 1905. Darwin’s Life and Letters.