But there is another class of human faculties that do not regard our fellow men, and which cannot, therefore, be thus accounted for. Such are the capacity to form ideal conceptions of space and time, of eternity and infinity—the capacity for intense artistic feelings of pleasure, in form, colour, and composition—and for those abstract notions of form and number which render geometry and arithmetic possible. How were all or any of these faculties first developed, when they could have been of no possible use to man in his early stages of barbarism? How could "natural selection," or survival of the fittest in the struggle for existence, at all favour the development of mental powers so entirely removed from the material necessities of savage men, and which even now, with our comparatively high civilization, are, in their farthest developments, in advance of the age, and appear to have relation rather to the future of the race than to its actual status?

Difficulty as to the Origin of the Moral Sense.

Exactly the same difficulty arises, when we endeavour to account for the development of the moral sense or conscience in savage man; for although the practice of benevolence, honesty, or truth, may have been useful to the tribe possessing these virtues, that does not at all account for the peculiar sanctity, attached to actions which each tribe considers right and moral, as contrasted with the very different feelings with which they regard what is merely useful. The utilitarian hypothesis (which is the theory of natural selection applied to the mind) seems inadequate to account for the development of the moral sense. This subject has been recently much discussed, and I will here only give one example to illustrate my argument. The utilitarian sanction for truthfulness is by no means very powerful or universal. Few laws enforce it. No very severe reprobation follows untruthfulness. In all ages and countries, falsehood has been thought allowable in love, and laudable in war; while, at the present day, it is held to be venial by the majority of mankind, in trade, commerce, and speculation. A certain amount of untruthfulness is a necessary part of politeness in the east and west alike, while even severe moralists have held a lie justifiable, to elude an enemy or prevent a crime. Such being the difficulties with which this virtue has had to struggle, with so many exceptions to its practice, with so many instances in which it brought ruin or death to its too ardent devotee, how can we believe that considerations of utility could ever invest it with the mysterious sanctity of the highest virtue,—could ever induce men to value truth for its own sake, and practice it regardless of consequences?

Yet, it is a fact, that such a mystical sense of wrong does attach to untruthfulness, not only among the higher classes of civilized people, but among whole tribes of utter savages. Sir Walter Elliott tells us (in his paper "On the Characteristics of the Population of Central and Southern India," published in the Journal of the Ethnological Society of London, vol. i., p. 107) that the Kurubars and Santals, barbarous hill-tribes of Central India, are noted for veracity. It is a common saying that "a Kurubar always speaks the truth;" and Major Jervis says, "the Santals are the most truthful men I ever met with." As a remarkable instance of this quality the following fact is given. A number of prisoners, taken during the Santal insurrection, were allowed to go free on parole, to work at a certain spot for wages. After some time cholera attacked them and they were obliged to leave, but every man of them returned and gave up his earnings to the guard. Two hundred savages with money in their girdles, walked thirty miles back to prison rather than break their word! My own experience among savages has furnished me with similar, although less severely tested, instances; and we cannot avoid asking, how is it, that in these few cases "experiences of utility" have left such an overwhelming impression, while in so many others they have left none? The experiences of savage men as regards the utility of truth, must, in the long run, be pretty nearly equal. How is it, then, that in some cases the result is a sanctity which overrides all considerations of personal advantage, while in others there is hardly a rudiment of such a feeling?

The intuitional theory, which I am now advocating, explains this by the supposition, that there is a feeling—a sense of right and wrong—in our nature, antecedent to and independent of experiences of utility. Where free play is allowed to the relations between man and man, this feeling attaches itself to those acts of universal utility or self-sacrifice, which are the products of our affections and sympathies, and which we term moral; while it may be, and often is, perverted, to give the same sanction to acts of narrow and conventional utility which are really immoral,—as when the Hindoo will tell a lie, but will sooner starve than eat unclean food; and looks upon the marriage of adult females as gross immorality.

The strength of the moral feeling will depend upon individual or racial constitution, and on education and habit;—the acts to which its sanctions are applied, will depend upon how far the simple feelings and affections of our nature, have been modified by custom, by law, or by religion.

It is difficult to conceive that such an intense and mystical feeling of right and wrong, (so intense as to overcome all ideas of personal advantage or utility), could have been developed out of accumulated ancestral experiences of utility; and still more difficult to understand, how feelings developed by one set of utilities, could be transferred to acts of which the utility was partial, imaginary, or altogether absent. But if a moral sense is an essential part of our nature, it is easy to see, that its sanction may often be given to acts which are useless or immoral; just as the natural appetite for drink, is perverted by the drunkard into the means of his destruction.

Summary of the Argument as to the Insufficiency of Natural Selection to account for the Development of Man.

Briefly to resume my argument—I have shown that the brain of the lowest savages, and, as far as we yet know, of the pre-historic races, is little inferior in size to that of the highest types of man, and immensely superior to that of the higher animals; while it is universally admitted that quantity of brain is one of the most important, and probably the most essential, of the elements which determine mental power. Yet the mental requirements of savages, and the faculties actually exercised by them, are very little above those of animals. The higher feelings of pure morality and refined emotion, and the power of abstract reasoning and ideal conception, are useless to them, are rarely if ever manifested, and have no important relations to their habits, wants, desires, or well-being. They possess a mental organ beyond their needs. Natural Selection could only have endowed savage man with a brain a little superior to that of an ape, whereas he actually possesses one very little inferior to that of a philosopher.

The soft, naked, sensitive skin of man, entirely free from that hairy covering which is so universal among other mammalia, cannot be explained on the theory of natural selection. The habits of savages show that they feel the want of this covering, which is most completely absent in man exactly where it is thickest in other animals. We have no reason whatever to believe, that it could have been hurtful, or even useless to primitive man; and, under these circumstances, its complete abolition, shown by its never reverting in mixed breeds, is a demonstration of the agency of some other power than the law of the survival of the fittest, in the development of man from the lower animals.

Other characters show difficulties of a similar kind, though not perhaps in an equal degree. The structure of the human foot and hand seem unnecessarily perfect for the needs of savage man, in whom they are as completely and as humanly developed as in the highest races. The structure of the human larynx, giving the power of speech and of producing musical sounds, and especially its extreme development in the female sex, are shown to be beyond the needs of savages, and from their known habits, impossible to have been acquired either by sexual selection, or by survival of the fittest.

The mind of man offers arguments in the same direction, hardly less strong than those derived from his bodily structure. A number of his mental faculties have no relation to his fellow men, or to his material progress. The power of conceiving eternity and infinity, and all those purely abstract notions of form, number, and harmony, which play so large a part in the life of civilised races, are entirely outside of the world of thought of the savage, and have no influence on his individual existence or on that of his tribe. They could not, therefore, have been developed by any preservation of useful forms of thought; yet we find occasional traces of them amidst a low civilization, and at a time when they could have had no practical effect on the success of the individual, the family, or the race; and the development of a moral sense or conscience by similar means is equally inconceivable.

But, on the other hand, we find that every one of these characteristics is necessary for the full development of human nature. The rapid progress of civilization under favourable conditions, would not be possible, were not the organ of the mind of man prepared in advance, fully developed as regards size, structure, and proportions, and only needing a few generations of use and habit to co-ordinate its complex functions. The naked and sensitive skin, by necessitating clothing and houses, would lead to the more rapid development of man's inventive and constructive faculties; and, by leading to a more refined feeling of personal modesty, may have influenced, to a considerable extent, his moral nature. The erect form of man, by freeing the hands from all locomotive uses, has been necessary for his intellectual advancement; and the extreme perfection of his hands, has alone rendered possible that excellence in all the arts of civilization which raises him so far above the savage, and is perhaps but the forerunner of a higher intellectual and moral advancement. The perfection of his vocal organs has first led to the formation of articulate speech, and then to the development of those exquisitely toned sounds, which are only appreciated by the higher races, and which are probably destined for more elevated uses and more refined enjoyment, in a higher condition than we have yet attained to. So, those faculties which enable us to transcend time and space, and to realize the wonderful conceptions of mathematics and philosophy, or which give us an intense yearning for abstract truth, (all of which were occasionally manifested at such an early period of human history as to be far in advance of any of the few practical applications which have since grown out of them), are evidently essential to the perfect development of man as a spiritual being, but are utterly inconceivable as having been produced through the action of a law which looks only, and can look only, to the immediate material welfare of the individual or the race.

The inference I would draw from this class of phenomena is, that a superior intelligence has guided the development of man in a definite direction, and for a special purpose, just as man guides the development of many animal and vegetable forms. The laws of evolution alone would, perhaps, never have produced a grain so well adapted to man's use as wheat and maize; such fruits as the seedless banana and bread-fruit; or such animals as the Guernsey milch cow, or the London dray-horse. Yet these so closely resemble the unaided productions of nature, that we may well imagine a being who had mastered the laws of development of organic forms through past ages, refusing to believe that any new power had been concerned in their production, and scornfully rejecting the theory (as my theory will be rejected by many who agree with me on other points), that in these few cases a controlling intelligence had directed the action of the laws of variation, multiplication, and survival, for his own purposes. We know, however, that this has been done; and we must therefore admit the possibility that, if we are not the highest intelligences in the universe, some higher intelligence may have directed the process by which the human race was developed, by means of more subtle agencies than we are acquainted with. At the same time I must confess, that this theory has the disadvantage of requiring the intervention of some distinct individual intelligence, to aid in the production of what we can hardly avoid considering as the ultimate aim and outcome of all organized existence—intellectual, ever-advancing, spiritual man. It therefore implies, that the great laws which govern the material universe were insufficient for his production, unless we consider (as we may fairly do) that the controlling action of such higher intelligences is a necessary part of those laws, just as the action of all surrounding organisms is one of the agencies in organic development. But even if my particular view should not be the true one, the difficulties I have put forward remain, and I think prove, that some more general and more fundamental law underlies that of "natural selection." The law of "unconscious intelligence" pervading all organic nature, put forth by Dr. Laycock and adopted by Mr. Murphy, is such a law; but to my mind it has the double disadvantage of being both unintelligible and incapable of any kind of proof. It is more probable, that the true law lies too deep for us to discover it; but there seems to me, to be ample indications that such a law does exist, and is probably connected with the absolute origin of life and organization. (Note A.)

The Origin of Consciousness.

The question of the origin of sensation and of thought can be but briefly discussed in this place, since it is a subject wide enough to require a separate volume for its proper treatment. No physiologist or philosopher has yet ventured to propound an intelligible theory, of how sensation may possibly be a product of organization; while many have declared the passage from matter to mind to be inconceivable. In his presidential address to the Physical Section of the British Association at Norwich, in 1868, Professor Tyndall expressed himself as follows:—

"The passage from the physics of the brain to the corresponding facts of consciousness is unthinkable. Granted that a definite thought, and a definite molecular action in the brain occur simultaneously, we do not possess the intellectual organ, nor apparently any rudiment of the organ, which would enable us to pass by a process of reasoning from the one phenomenon to the other. They appear together, but we do not know why. Were our minds and senses so expanded, strengthened, and illuminated as to enable us to see and feel the very molecules of the brain; were we capable of following all their motions, all their groupings, all their electric discharges, if such there be, and were we intimately acquainted with the corresponding states of thought and feeling, we should be as far as ever from the solution of the problem, 'How are these physical processes connected with the facts of consciousness?' The chasm between the two classes of phenomena would still remain intellectually impassable."

In his latest work ("An Introduction to the Classification of Animals,") published in 1869, Professor Huxley unhesitatingly adopts the "well founded doctrine, that life is the cause and not the consequence of organization." In his celebrated article "On the Physical Basis of Life," however, he maintains, that life is a property of protoplasm, and that protoplasm owes its properties to the nature and disposition of its molecules. Hence he terms it "the matter of life," and believes that all the physical properties of organized beings are due to the physical properties of protoplasm. So far we might, perhaps, follow him, but he does not stop here. He proceeds to bridge over that chasm which Professor Tyndall has declared to be "intellectually impassable," and, by means which he states to be logical, arrives at the conclusion, that our "thoughts are the expression of molecular changes in that matter of life which is the source of our other vital phenomena." Not having been able to find any clue in Professor Huxley's writings, to the steps by which he passes from those vital phenomena, which consist only, in their last analysis, of movements of particles of matter, to those other phenomena which we term thought, sensation, or consciousness; but, knowing that so positive an expression of opinion from him will have great weight with many persons, I shall endeavour to show, with as much brevity as is compatible with clearness, that this theory is not only incapable of proof, but is also, as it appears to me, inconsistent with accurate conceptions of molecular physics. To do this, and in order further to develop my views, I shall have to give a brief sketch of the most recent speculations and discoveries, as to the ultimate nature and constitution of matter.

The Nature of Matter.

It has been long seen by the best thinkers on the subject, that atoms,—considered as minute solid bodies from which emanate the attractive and repulsive forces which give what we term matter its properties,—could serve no purpose whatever; since it is universally admitted that the supposed atoms never touch each other, and it cannot be conceived that these homogeneous, indivisible, solid units, are themselves the ultimate cause of the forces that emanate from their centres. As, therefore, none of the properties of matter can be due to the atoms themselves, but only to the forces which emanate from the points in space indicated by the atomic centres, it is logical continually to diminish their size till they vanish, leaving only localized centres of force to represent them. Of the various attempts that have been made to show how the properties of matter may be due to such modified atoms (considered as mere centres of force), the most successful, because the simplest and the most logical, is that of Mr. Bayma, who, in his "Molecular Mechanics," has demonstrated how, from the simple assumption of such centres having attractive and repulsive forces (both varying according to the same law of the inverse squares as gravitation), and by grouping them in symmetrical figures, consisting of a repulsive centre, an attractive nucleus, and one or more repulsive envelopes, we may explain all the general properties of matter; and, by more and more complex arrangements, even the special chemical, electrical, and magnetic properties of special forms of matter.[I] Each chemical element will thus consist of a molecule formed of simple atoms, (or as Mr. Bayma terms them to avoid confusion, "material elements") in greater or less number and of more or less complex arrangement; which molecule is in stable equilibrium, but liable to be changed in form by the attractive or repulsive influences of differently constituted molecules, constituting the phenomena of chemical combination, and resulting in new forms of molecule of greater complexity and more or less stability.

[I] Mr. Bayma's work, entitled "The Elements of Molecular Mechanics," was published in 1866, and has received less attention than it deserves. It is characterised by great lucidity, by logical arrangement, and by comparatively simple geometrical and algebraical demonstrations, so that it may be understood and appreciated with a very moderate knowledge of mathematics. It consists of a series of Propositions, deduced from the known properties of matter; from these are derived a number of Theorems, by whose help the more complicated Problems are solved. Nothing is taken for granted throughout the work, and the only valid mode of escaping from its conclusions is, by either disproving the fundamental Propositions, or by detecting fallacies in the subsequent reasoning.

Those organic compounds of which organized beings are built up, consist, as is well known, of matter of an extreme complexity. and great instability; whence result the changes of form to which it is continually subject. This view enables us to comprehend the possibility, of the phenomena of vegetative life being due to an almost infinite complexity of molecular combinations, subject to definite changes under the stimuli of heat, moisture, light, electricity, and probably some unknown forces. But this greater and greater complexity, even if carried to an infinite extent, cannot, of itself, have the slightest tendency to originate consciousness in such molecules or groups of molecules. If a material element, or a combination of a thousand material elements in a molecule, are alike unconscious, it is impossible for us to believe, that the mere addition of one, two, or a thousand other material elements to form a more complex molecule, could in any way tend to produce a self-conscious existence. The things are radically distinct. To say that mind is a product or function of protoplasm, or of its molecular changes, is to use words to which we can attach no clear conception. You cannot have, in the whole, what does not exist in any of the parts; and those who argue thus should put forth a definite conception of matter, with clearly enunciated properties, and show, that the necessary result of a certain complex arrangement of the elements or atoms of that matter, will be the production of self-consciousness. There is no escape from this dilemma,—either all matter is conscious, or consciousness is something distinct from matter, and in the latter case, its presence in material forms is a proof of the existence of conscious beings, outside of, and independent of, what we term matter. (Note B.)

Matter is Force.—The foregoing considerations lead us to the very important conclusion, that matter is essentially force, and nothing but force; that matter, as popularly understood, does not exist, and is, in fact, philosophically inconceivable. When we touch matter, we only really experience sensations of resistance, implying repulsive force; and no other sense can give us such apparently solid proofs of the reality of matter, as touch does. This conclusion, if kept constantly present in the mind, will be found to have a most important bearing on almost every high scientific and philosophical problem, and especially on such as relate to our own conscious existence.

All Force is probably Will-Force.—If we are satisfied that force or forces are all that exist in the material universe, we are next led to enquire what is force? We are acquainted with two radically distinct or apparently distinct kinds of force—the first consists of the primary forces of nature, such as gravitation, cohesion, repulsion, heat, electricity, &c.; the second is our own will-force. Many persons will at once deny that the latter exists. It will be said, that it is a mere transformation of the primary forces before alluded to; that the correlation of forces includes those of animal life, and that will itself is but the result of molecular change in the brain. I think, however, that it can be shown, that this latter assertion has neither been proved, nor even been proved to be possible; and that in making it, a great leap in the dark has been taken from the known to the unknown. It may be at once admitted that the muscular force of animals and men, is merely the transformed energy derived from the primary forces of nature. So much has been, if not rigidly proved, yet rendered highly probable, and it is in perfect accordance with all our knowledge of natural forces and natural laws. But it cannot be contended that the physiological balance-sheet has ever been so accurately struck, that we are entitled to say, not one-thousandth part of a grain more of force has been exerted by any organized body or in any part of it, than has been derived from the known primary forces of the material world. If that were so, it would absolutely negative the existence of will; for if will is anything, it is a power that directs the action of the forces stored up in the body, and it is not conceivable that this direction can take place, without the exercise of some force in some part of the organism. However delicately a machine may be constructed, with the most exquisitely contrived detents to release a weight or spring by the exertion of the smallest possible amount of force, some external force will always, be required; so, in the animal machine, however minute may be the changes required in the cells or fibres of the brain, to set in motion the nerve currents which loosen or excite the pent up forces of certain muscles, some force must be required to effect those changes. If it is said, "those changes are automatic, and are set in motion by external causes," then one essential part of our consciousness, a certain amount of freedom in willing, is annihilated; and it is inconceivable how or why there should have arisen any consciousness or any apparent will, in such purely automatic organisms. If this were so, our apparent WILL would be a delusion, and Professor Huxley's belief—"that our volition counts for something as a condition of the course of events," would be fallacious, since our volition would then be but one link in the chain of events, counting for neither more nor less than any other link whatever.

If, therefore, we have traced one force, however minute, to an origin in our own WILL, while we have no knowledge of any other primary cause of force, it does not seem an improbable conclusion that all force may be will-force; and thus, that the whole universe, is not merely dependent on, but actually is, the WILL of higher intelligences or of one Supreme Intelligence. It has been often said that the true poet is a seer; and in the noble verse of an American poetess, we find expressed, what may prove to be the highest fact of science, the noblest truth of philosophy:

God of the Granite and the Rose! Soul of the Sparrow and the Bee! The mighty tide of Being flows Through countless channels, Lord, from thee. It leaps to life in grass and flowers, Through every grade of being runs, While from Creation's radiant towers Its glory flames in Stars and Suns.

Conclusion.

These speculations are usually held to be far beyond the bounds of science; but they appear to me to be more legitimate deductions from the facts of science, than those which consist in reducing the whole universe, not merely to matter, but to matter conceived and defined so as to be philosophically inconceivable. It is surely a great step in advance, to get rid of the notion that matter is a thing of itself, which can exist per se, and must have been eternal, since it is supposed to be indestructible and uncreated,—that force, or the forces of nature, are another thing, given or added to matter, or else its necessary properties,—and that mind is yet another thing, either a product of this matter and its supposed inherent forces, or distinct from and co-existent with it;—and to be able to substitute for this complicated theory, which leads to endless dilemmas and contradictions, the far simpler and more consistent belief, that matter, as an entity distinct from force, does not exist; and that FORCE is a product of MIND. Philosophy had long demonstrated our incapacity to prove the existence of matter, as usually conceived; while it admitted the demonstration to each of us of our own self-conscious, ideal existence. Science has now worked its way up to the same result, and this agreement between them should give us some confidence in their combined teaching.

The view we have now arrived at seems to me more grand and sublime, as well as far simpler, than any other. It exhibits the universe, as a universe of intelligence and will-power; and by enabling us to rid ourselves of the impossibility of thinking of mind, but as connected with our old notions of matter, opens up infinite possibilities of existence, connected with infinitely varied manifestations of force, totally distinct from, yet as real as, what we term matter.

The grand law of continuity which we see pervading our universe, would lead us to infer infinite gradations of existence, and to people all space with intelligence and will-power; and, if so, we have no difficulty in believing that for so noble a purpose as the progressive development of higher and higher intelligences, those primal and general will-forces, which have sufficed for the production of the lower animals, should have been guided into new channels and made to converge in definite directions. And if, as seems to me probable, this has been done, I cannot admit that it in any degree affects the truth or generality of Mr. Darwin's great discovery. It merely shows, that the laws of organic development have been occasionally used for a special end, just as man uses them for his special ends; and, I do not see that the law of "natural selection" can be said to be disproved, if it can be shown that man does not owe his entire physical and mental development to its unaided action, any more than it is disproved by the existence of the poodle or the pouter pigeon, the production of which may have been equally beyond its undirected power.

The objections which in this essay I have taken, to the view,—that the same law which appears to have sufficed for the development of animals, has been alone the cause of man's superior physical and mental nature,—will, I have no doubt, be over-ruled and explained away. But I venture to think they will nevertheless maintain their ground, and that they can only be met by the discovery of new facts or new laws, of a nature very different from any yet known to us. I can only hope that my treatment of the subject, though necessarily very meagre, has been clear and intelligible; and that it may prove suggestive, both to the opponents and to the upholders of the theory of Natural Selection.



NOTES.

NOTE A. (Page 360.)

Some of my critics seem quite to have misunderstood my meaning in this part of the argument. They have accused me of unnecessarily and unphilosophically appealing to "first causes" in order to get over a difficulty—of believing that "our brains are made by God and our lungs by natural selection;" and that, in point of fact, "man is God's domestic animal." An eminent French critic, M. Claparede, makes me continually call in the aid of—"une Force superieure," the capital F, meaning I imagine that this "higher Force" is the Deity. I can only explain this misconception by the incapacity of the modern cultivated mind to realise the existence of any higher intelligence between itself and Deity. Angels and archangels, spirits and demons, have been so long banished from our belief as to have become actually unthinkable as actual existences, and nothing in modern philosophy takes their place. Yet the grand law of "continuity," the last outcome of modern science, which seems absolute throughout the realms of matter, force, and mind, so far as we can explore them, cannot surely fail to be true beyond the narrow sphere of our vision, and leave an infinite chasm between man and the Great Mind of the universe. Such a supposition seems to me in the highest degree improbable.

Now, in referring to the origin of man, and its possible determining causes, I have used the words "some other power"—"some intelligent power"—"a superior intelligence"—"a controlling intelligence," and only in reference to the origin of universal forces and laws have I spoken of the will or power of "one Supreme Intelligence." These are the only expressions I have used in alluding to the power which I believe has acted in the case of man, and they were purposely chosen to show, that I reject the hypothesis of "first causes" for any and every special effect in the universe, except in the same sense that the action of man or of any other intelligent being is a first cause. In using such terms I wished to show plainly, that I contemplated the possibility that the development of the essentially human portions of man's structure and intellect may have been determined by the directing influence of some higher intelligent beings, acting through natural and universal laws. A belief of this nature may or may not have a foundation, but it is an intelligible theory, and is not, in its nature, incapable of proof; and it rests on facts and arguments of an exactly similar kind to those, which would enable a sufficiently powerful intellect to deduce, from the existence on the earth of cultivated plants and domestic animals, the presence of some intelligent being of a higher nature than themselves.

NOTE B. (Page 365.)

A friend has suggested that I have not here explained myself sufficiently, and objects, that life does not exist in matter any more than consciousness, and if the one can be produced by the laws of matter, why may not the other? I reply, that there is a radical difference between the two. Organic or vegetative life consists essentially in chemical transformations and molecular motions, occurring under certain conditions and in a certain order. The matter, and the forces which act upon it, are for the most part known; and if there are any forces engaged in the manifestation of vegetative life yet undiscovered (which is a moot question), we can conceive them as analogous to such forces as heat, electricity, or chemical affinity, with which we are already acquainted. We can thus clearly conceive of the transition from dead matter to living matter. A complex mass which suffers decomposition or decay is dead, but if this mass has the power of attracting to itself, from the surrounding medium, matter like that of which it is composed, we have the first rudiment of vegetative life. If the mass can do this for a considerable time, and if its absorption of new matter more than replaces that lost by decomposition, and if it is of such a nature as to resist the mechanical or chemical forces to which it is usually exposed, and to retain a tolerably constant form, we term it a living organism. We can conceive an organism to be so constituted, and we can further conceive that any fragments, which may be accidentally broken from it, or which may fall away when its bulk has become too great for the cohesion of all its parts, may begin to increase anew and run the same course as the parent mass. This is growth and reproduction in their simplest forms; and from such a simple beginning it is possible to conceive a series of slight modifications of composition, and of internal and external forces, which should ultimately lead to the development of more complex organisms. The LIFE of such an organism may, perhaps, be nothing added to it, but merely the name we give to the result of a balance of internal and external forces in maintaining the permanence of the form and structure of the individual. The simplest conceivable form of such life would be the dewdrop, which owes its existence to the balance between the condensation of aqueous vapour in the atmosphere and the evaporation of its substance. If either is in excess, it soon ceases to maintain an individual existence. I do not maintain that vegetative life is wholly due to such a complex balance of forces, but only that it is conceivable as such.

With CONSCIOUSNESS the case is very different. Its phenomena are not comparable with those of any kind of matter subjected to any of the known or conceivable forces of nature; and we cannot conceive a gradual transition from absolute unconsciousness to consciousness, from an unsentient organism to a sentient being. The merest rudiment of sensation or self-consciousness is infinitely removed from absolutely non-sentient or unconscious matter. We can conceive of no physical addition to, or modification of, an unconscious mass which should create consciousness; no step in the series of changes organised matter may undergo, which should bring in sensation where there was no sensation or power of sensation at the preceding step. It is because the things are utterly incomparable and incommensurable that we can only conceive of sensation coming to matter from without, while life may be conceived as merely a specific combination and co-ordination of the matter and the forces that compose the universe, and with which we are separately acquainted. We may admit with Professor Huxley that protoplasm is the "matter of life" and the cause of organisation, but we cannot admit or conceive that protoplasm is the primary source of sensation and consciousness, or that it can ever of itself become conscious in the same way as we may perhaps conceive that it may become alive.



INDEX.

ABRAXAS grossulariata, 119.

Acanthotritus dorsalis, 94.

Accipiter pileatus, 107.

ACRAEIDAE, the subjects of mimicry, 85, 86.

Acronycta psi, protective colouring of, 62.

ADAPTATION brought about by general laws, 276; looks like design, 281.

AEGERIIDAE mimic Hymenoptera, 90.

AGASSIZ, or embryonic character of ancient animals, 301.

Agnia fasciata, mimics another Longicorn, 95.

Agriopis aprilina, protective colouring of, 62.

ALCEDINIDAE, sexual colouring and nidification of, 240.

AMADINA, sexual colouring and nidification of, 243.

AMPELIDAE, sexual colouring and nidification of, 243.

ANCYLOTHERIUM, 300.

ANDRENIDAE, 98.

Angraecum sesquipedale, 272; its fertilization by a large moth, 275.

ANIMALS, senses and faculties of, 127; intellect of, compared with that of savages, 341.

ANISOCERINAE, 92.

ANOA, 196.

ANOPLOTHERIUM, 299.

ANTHRIBIDAE, mimicry of, 94; dimorphism in, 155.

Anthrocera filipendulae, 120.

ANTHROPOLOGISTS, wide difference of opinion among, as to origin of human races, 304; conflicting views of, harmonized, 321.

ANTIQUITY of man, 303, 322.

APATHUS, 98.

APPARENT exceptions to law of colour and nidification, 253.

AQUATIC BIRDS, why abundant, 32.

Araschnia prorsa, 154.

ARCHEGOSAURUS, 300.

ARCHAEOPTERYX, 300.

ARCHITECTURE of most nations derivative, 228; Grecian, false in principle, 226.

ARCTIC animals, white colour of, 50, 51.

ARGYLL, Duke of, on colours of Woodcock, 53; on mind in nature, 265; criticism on Darwin's works, 269; on humming birds 282; on creation by birth, 287.

ASILUS, 97.

ASPECTS of nature as influencing man's development, 317.

BABIRUSA, 196.

BALANCE in nature, 42.

BARRINGTON, Hon. Daines, on song of birds, 220.

BASILORNIS, 196.

BATES, Mr., first adopted the word "mimicry," 75; his observations on Leptalis and Heliconidae, 82; his paper explaining the theory of mimicry, 83; objections to his theory, 108; on variation, 165; on recent immigration of Amazonian Indians, 214.

BAYMA, Mr., on "Molecular Mechanics," 363, 364.

BEAUTY in nature, 282; not universal, 284; of flowers useful to them, 285; not given for its own sake, 285.

BIRDS, possible rapid increase of, 29; numbers that die annually, 30; mimicry among, 103; dull colour of females, 114; nidification as affecting colour of females, 116; refusing the gooseberry caterpillar, 119; the highest in rank and organization, 137; dimorphism in, 155; why peculiar nest built by each species, 215-219; build more perfect nests as they grow older, 224, 227; alter and improve their nests, 226; sexual differences of colour in, 239.

Bombus hortorum, 90.

Bombycilla, garrula, colours and nidification of, 255.

BOMBYLIUS, 98.

BRAIN of the savage but slightly less than that of civilized man, 336; size of, an important element of mental power, 335; of savage races larger than their needs require, 338, 343; of man and of anthropoid apes compared, 338.

BROCA, Professor Paul, on the fine crania of the cave men, 337.

Bryophila glandifera and B. perla protectively coloured, 63.

BUCEROTIDAE, sexual colouring and nidification of, 241.

BUCCONIDAE, sexual colouring and nidification of, 241.

BUFF-TIP moth, resembles a broken stick, 62.

BUILDINGS of various races do not change, 213.

BUPRESTIDAE, resembling bird's dung, 57; similar colours in two sexes, 114.

BUTTERFLIES, value of, in studying "natural selection," 131; varieties of, in Sardinia and Isle of Man, 178.

CACIA anthriboides, 94.

Callizona acesta, protective colouring of, 59.

CALORNIS, 239.

CAPITONIDAE, sexual colouring and nidification of, 241.

Capnolymma stygium, 94.

CARABIDAE, special protection among, 72; similar colouring of two sexes, 114.

CASSIDAE, resemble dew drops, 58.

CATERPILLARS, mimicking a poisonous snake, 99; gaudy colours of, 117; various modes of protection of, 118; gooseberry caterpillar, 119; Mr. Jenner Weir's observations on, 119; Mr. A. G. Butler's observations on, 121.

CELEBES, local modifications of form in, 170; probable cause of these, 176; remarkable zoological peculiarities of, 195-199.

CENTROPUS, sexual colouring and nidification of, 242.

Cephalodonta spinipes, 92.

Ceroxylus laceratus, imitates a moss-covered stick, 64.

CERTHIOLA, sexual colouring and nidification of, 244.

Cethosia aeole, 172; biblis, 172.

CETONIADAE, how protected, 73; similar colours of two sexes, 114.

CEYCOPSIS, 196.

Charis melipona, 96.

CHEMATOBIA, wintry colours of this genus, 62.

Chlamys pilula, resembles dung of caterpillars, 58.

CHRYSIDIDAE, how protected, 72.

CHRYSOMELIDAE, similar colouring of two sexes, 114.

CICINDELA, adaptive colour of various species of, 57.

Cilix compressa, resembles bird's dung, 63.

CLADOBATES, mimicking squirrels, 107.

CLASSIFICATION, form of true, 6; circular, inadmissible, 8; quinarian and circular, of Swainson, 46; argument from, against Mr. Darwin, 295.

CLIMACTERIS, sexual colouring and nidification of, 243.

COCCINELLIDAE, how protected, 72; similar colouring of sexes, 114.

COEXISTING varieties, 159.

Collyrodes lacordairei, 95.

COLOUR, in animals, popular theories of, 47; frequent variations of, in domesticated animals, 48; influenced by need of concealment, 49; in deserts, 49, 50; in Arctic regions, 50, 51; nocturnal, 51; tropical, 52; special modifications of, 52; different distribution of, in butterflies and moths, 58; of autumnal and winter moths, 62; white, generally dangerous and therefore eliminated, 66; why it exists so abundantly although often injurious, 69; influenced by need of protection, 113; of female birds, 114; in relation to nidification of birds, 116; gaudy colours of many caterpillars, 117; in nature, general causes of, 126; local variations of, 173; sexual differences of, in birds, 239; in female birds, how connected with their nidification, 240, 246; more variable than structure or habits, and therefore more easily modified, 249; of flowers, as explained by Mr. Darwin, 262; often correlated with disease, 316.

COMPSOGNATHUS, 300.

Condylodera tricondyloides, 97.

CONSCIOUSNESS, origin of, 360; Professor Tyndall on, 361; not a product of complex organization, 365.

CORRELATION of growth, 310.

Corynomalus sp., 92.

COTINGIDAE, sexual colouring and nidification of, 244.

CRATOSOMUS, a hard weevil, 94.

CRICKETS mimicking sand wasps, 98.

CRYPTODONTIA, 299.

Cucullia verbasci, 120.

CURCULIONIDAE, often protected by hard covering, 71; similar colours of two sexes, 114.

Cuviera squamata, 258.

Cyclopeplus batesii, 92.

CYNOPITHECUS, 196.

Cynthia arsinoe, 172.

DANAIDAE, the subjects of mimicry, 85, 86.

Danais erippus, 88; chysippus, 112; sobrina, 179; aglaia, 179; tytia, 180.

DARWIN, Mr., his principle of utility, 47; on cause of colour in flowers, 127, 262; on colours of caterpillars, 118; on sexual colouration, 260; his metaphors liable to misconception, 269; criticism of, in North British Review, 291.

DESERT animals, colours of, 49, 50.

DIADEMA, species of, mimic Danaidae, 86, 87; female with male colouration, 112.

Diadema misippus, 112; D. anomala, 113.

Diaphora mendica, 89.

DICNYODONTIA, 299.

DICROURUS, 253.

Diloba coeruleocephala, 120.

DIMORPHISM, 145; in beetles, 155; in birds, 155; illustrated, 157.

DINOSAURIA, 298.

DIPTERA mimicking wasps and bees, 97.

Doliops curculionides, 94.

DOMESTICATED animals, their essential difference from wild ones, 38-41.

DOTTERELL, 251.

DRUSILLA, mimicked by three genera, 181.

Drusilla bioculata, 180.

DYTISCUS, dimorphism in, 155.

EGYPTIAN architecture, introduced, 225.

Elaps fulvius, E. corallinus, E. lemniscatus, 101; E. mipartitus, E. lemniscatus, E. hemiprichii, 102.

ENODES, 196.

ENNOMUS, autumnal colours of this genus, 62.

Eos fuscata, dimorphism of, 155.

EQUUS, 299.

Eronia tritaea, 172; valeria, 172.

Eroschema poweri, 93.

ERYCINIDAE mimic Heliconidae, 84.

Erythroplatis corallifer, 92.

ESTRELDA, sexual colouring and nidification of, 243.

EUCNEMIDAE, mimicking a Malacoderm, 93.

Eudromias morinellus, 251.

Euglossa dimidiata, 98.

EUMORPHIDAE, a protected group 72; imitated by Longicorns, 92.

EUPLOEA, local modifications of colour in, 173.

Euploea midamus, 87-113, 179; E. rhadamanthus, 87, 179.

Eurhinia megalonice, 172; polynice, 172.

EURYLAEMIDAE, sexual colouring and nidification of, 243.

EXTINCT animals, intermediate forms of, 298.

EXTINCTION of lower races, 318.

FEMALE birds, colours of, 114; sometimes connected with their mode of nidification, 240; more exposed to enemies than the males, 248.

FEMALE butterflies generally dull-coloured, 259.

FEMALE insects, mimicry by, 110, 259; colours of, 113.

FEMALE sex, has no incapacity for as brilliant colouration as the male, 247; in some groups requires more protection than the male, 258.

FISHES, protective colouring of, 55.

FISSIROSTRAL birds, nests of, 238.

FLOWERS, causes of colour in, 127.

FLYCATCHERS, genera of, absent from Celebes, 177.

FORBES, EDWARD, objections to his theory of Polarity, 17-23.

FORCE is probably all Will-force, 366.

GALAPAGOS, 10.

GALTON, Mr., on range of intellectual power, 339.

GANOCEPHALA, 298.

Gastropacha querci, protective colour and form of, 62.

GAUDRY, M., on fossil mammals of Greece, 299.

GEOGRAPHICAL distribution, dependent on geologic changes, 1; its agreement with law of introduction of new species, 9; of allied species and groups, 12.

GEOLOGICAL distribution analogous to geographical, 13.

GEOLOGY, facts proved by, 2-5.

GIRAFFE, how it acquired its long neck, 42.

GLAEA, autumnal colours of this genus, 62.

GOULD, Mr., on sexual plumage of Gray Phalarope, 115; on incubation by male Dotterell, 115.

Grallina australis, 254.

GREEN birds almost confined to the tropics, 52.

Gymnocerus cratosomoides, 94.

Gymnocerous capucinus, 96.

Gymnocerous dulcissimus, 97.

GUNTHER, Dr., on arboreal snakes, 55; on colouring of snakes, 102.

Gynecia dirce, 59.

HABITS, often persistent when use of them has ceased, 234; of children and savages analogous to those of animals, 235; if persistent and imitative may be termed hereditary, 235, 236.

HAIRY covering of Mammalia, use of, 344; absence of, in man remarkable, 345; the want of it felt by savages, 346; could not have been abolished by natural selection, 348.

Harpagus diodon, 107.

HEILIPLUS, a hard genus of Curculionidae, 94.

HELICONIDAE, the objects of mimicry, 77; their secretions, 88; not attacked by birds, 79; sometimes mimicked by other Heliconidae, 85.

HELLADOTHERIUM, 300.

HEMIPTERA, protected by bad odour, 72.

HERBERT, Rev. W., on song of birds, 221.

HESPERIDAE, probable means of protection of, 176.

HESTHESIS, longicorns resembling ants, 96.

Hestia leuconoe, 180.

HEWITSON, Mr., 131.

HIPPARION, 299.

HIPPOTHERIUM, 299.

HISPIDAE, imitated by Longicorns, 92.

HOLOTHURIDAE, 258.

Homalocranium semicinctum, 101.

HOOKER, Dr., on the value of the "specific term," 165.

HOUSES of American and Malay races contrasted, 213.

HUXLEY, Professor, on "Physical Basis of Life," 362; on volition, 368.

HYAENICTIS, 300.

HYBERNIA, wintry colours of this genus, 62.

HYMENOPTERA, large number of, peculiar to Celebes, 196.

ICTERIDAE, sexual colouring and nidification of, 244.

ICTHYOPTERYGIA, 298.

Ideopsis daos, 180.

IMITATION, the effects of, in man's works, 212.

INDIANS, how they travel through trackless forests, 207.

INSECTS, protective colouring of, 56; mimicking species of other orders, 97; senses of, perhaps different from ours, 202, 203.

INSTINCT, how it may be best studied, 201; definition of, 203; in many cases assumed without proof, 205; if possessed by man, 206; supposed, of Indians, 207; supposed to be shown in the construction of birds' nests, 211.

INTELLECT of savages compared with that of animals, 341.

INTELLECTUAL power, range of, in man, 339.

Iphias glaucippe, 172.

ITHOMIA, mimicked by Leptalis, 83.

Ithomia ilerdina, mimicked by four groups of Lepidoptera, 84.

JAVA, relations of, to Sumatra and Borneo, 193.

JAMAICA swift altering position of nest, 228.

JERDON, Mr., on incubation by males in Turnix, 115.

Kallima inachis and Kallima paralekta, wonderful resemblance of, to leaves, 59-61.

LABYRINTHODONTIA, 298, 300.

LAKES as cases of imperfect adaptation, 278.

LANIADAE, sexual colouring and nidification of, 245.

LAMARCK'S hypothesis very different from the author's, 41.

Larentia tripunctaria, 63.

LAW which has regulated the introduction of new species, 5; confirmed by geographical distribution, 9; high organization of ancient animals consistent with, 14; of multiplication in geometrical progression, 265; of limited populations, 265; of heredity, 266; of variation, 266; of change of physical conditions, 266; of the equilibrium of nature, 266; as opposed to continual interference, 268.

LAYCOCK, Dr., on law of "unconscious intelligence," 360.

LEAF BUTTERFLY, appearance and habits of, 59-61.

LEPIDOPTERA, especially subject to variation, 132.

LEPTALIS, species of mimic Heliconidae, 82; gain a protection thereby, 259.

LESTER, Mr. J. M., on wood-dove and robin, 53.

LEVAILLANT, on formation of a nest, 224.

Limenitis archippus, 88.

Limenitis limire, 172; procris, 172.

LIZARDS refusing certain moths and caterpillars, 121; devouring bees, 121.

LOCAL FORMS, 158.

LOCAL variation of form, 169; of colour, 173; general remarks on, 174; in Celebesian butterflies, probable use of, 175.

LOCUSTIDAE, adaptive colouring of, 64.

LUMINOUSNESS of some insects a protection, 71.

LYCAENIDAE, probable means of protection of, 176.

MAMMALS, mimicry among, 107.

MAN, does he build by reason or imitation, 212; his works mainly imitative, 225; antiquity of, 303, 322; difference of opinion as to his origin, 304; unity or plurality of species, 305; persistence of type of, 306; importance of mental and moral characters, 312; his dignity and supremacy, 324; his influence on nature, 326; his future development, 326; range of intellectual power in, 339; rudiments of all the higher faculties in savage, 341; his feet and hands, difficulties on the theory of natural selection, 349; his voice, 350; his mental faculties, 351; difficulty as to the origin of the moral sense in, 352; development of, probably directed by a superior intelligence, 359.

MANTIDAE, adaptive colouring of, 64; mimicking white ants, 98.

MALACODERMS, a protected group, 93.

MALURIDAE, 255.

MATTER, the nature of, 363; Mr. Bayma on, 363; is force, 365.

MECHANITIS and Methona, mimicked by Leptalis, 83.

MECOCERUS, dimorphism of, 155.

Mecocerus gazella, 94.

MEGACEPHALON, 196.

MEGAPODIDAE, sexual colouring and nidification of, 246.

MEROPOGON, 196.

Midas dives, 97.

MIMETA, mimicking Tropidorhynchus, 104.

MIMICRY, meaning of the word, 74; theory of, 76; among Lepidoptera, 77; how it acts as a protection, 80, 81; of other insects by Lepidoptera, 89; among beetles, 91; of other insects by beetles, 95; of insects by species of other orders, 97; among the vertebrata, 99; among snakes, 101; among tree frogs, 103; among birds, 103; among mammals, 107; objections to the theory of, 108; by female insects, 110; among Papilionidae, 179; never occurs in the male only, 260.

MOMOTIDAE, sexual colouring and nidification of, 241.

MONTROUZIER, M., on butterflies of Woodlark Island, 152.

MORAL sense, difficulty as to the origin of, 352.

MORPHOS, how protected, 73.

MURRAY, Mr. Andrew, objections to theory of mimicry, 108.

MUSCICAPIDAE, sexual colouring and nidification of, 245.

MUSOPHAGIDAE, sexual colouring and nidification of, 242.

NAPEOGENES, all the species are mimickers, 85.

NATURAL selection, the principle stated, 41-43; general acceptance of the theory of, 46; tabular demonstration of, 302; outline of theory of, 307; its effects on man and animals different, 311; hardly acts among civilized societies, 330; what it can not do, 333; cannot produce injurious or useless modifications, 334.

NECTARINEIDAE, 254.

NECYDALIDAE, mimic Hymenoptera, 96.

Nemophas grayi, a Longicorn mimicked by a Longicorn, 95.

NESTS of Birds, why different, 215; of young birds, how built, 219; construction of, described by Levaillant, 224; imperfections in, 229; influenced by changed conditions and persistent habits, 232; classification of, according to function, 237.

NEW FORMS, how produced by variation and selection, 286.

NEW GUINEA, relation of the several Papuan islands to, 194.

NOCTURNAL animals, colours of, 51.

NOMADA, 98.

OBEREA, species resemble Tenthredinidae, 96.

Odontocera odyneroides, 96.

ODONTOCHEILA, 97.

Odyncrus sinuatus, 90.

Onthophilus sulcatus, like a seed, 58.

Onychocerus scorpio, resembles bark, 56.

ORANGE-TIP butterfly, protective colouring of, 59.

ORCHIS, structure of an, explained by natural selection, 271.

Orgyia antiqua and O. gonostigma, autumnal colours of, 62.

ORIOLIDAE, 253.

Ornithoptera priamus, 145, 173; O. helena, 173.

Oxyrhopus petolarius, O. trigeminus, O. formosus, 102.

OWEN, Professor, on more generalized structure of extinct animals, 298.

Pachyotris fabricii, 96.

PACHYRHYNCHI, weevils mimicked by Longicorns, 95.

PALEOTHERIUM, 299.

PALOPLOTHERIUM, 299.

PAPILIO, black and red group imitated, 84.

Papilio achates, 147; P. adamantius, 171; P. aenigma, 87; P. agamemnon, 141, 158, 170, 171; P. agestor, 180; P. alphenor, 148, 169; P. amanga, 151; P. androcles, 171; P. androgeus, 88, 147, 180, 183; P. antiphates, 141, 171; P. antiphus, 87, 150, 170, 180, 183; P. aristaeus, 171; P. arjuna, 141; P. ascalaphus, 171; P. autolycus, 160; P. bathycles, 141; P. blumei, 171; P. brama, 171; P. caunus, 87, 179; P. codrus, 160, 171; P. coeon, 88, 146, 180, 182; P. deiphobus, 140; P. deiphontes, 171; P. delessertii, 180; P. demolion, 171; P. diphilus, 87, 170, 180, 183; P. doubledayi, 88, 180; P. elyros, 148; P. encelades, 171; P. erectheus, 151; P. euripilus, 160; P. evemon, 159; P. gigon, 171; P. glaucus, 152; P. hector, 87, 150, 180, 183; P. helenus, 160, 171; P. hospiton, 178; P. idaeoides, 180; P. jason, 159, 171; P. ledebouria, 148; P. leucothoe, 171; P. leodamas, 170; P. liris, 87, 180, 184; P. macareus, 179; P. machaon, 178; P. melanides, 148, 150; P. memnon, 88, 140, 146, 147, 152, 180, 183; P. milon, 171; P. nephelus, 140; P. nicanor, 170; P. oenomaus, 88, 180, 184; P. onesimus, 151; P. ormenus, 150, 152, 182; P. pammon, 147, 152, 170, 180; P. pamphylus, 171; P. pandion, 152, 180; P. paradoxa, 87, 179; P. peranthus, 160, 171; P. pertinax, 145; P. philoxenus, 182; P. polydorus, 88, 170, 182; P. polytes, 147, 148; P. rhesus, 171; P. romulus, 87, 148, 150, 183; P. sarpedon, 141, 158, 171; P. sataspes, 171; P. severus, 140, 144; P. theseus, 87, 148, 150, 169, 170, 171, 180, 183; P. thule, 179; P. torquatus, 156; P. turnus, 152; P. ulysses, 140, 160, 173; P. varuna, 88.

PAPILIONIDAE, the question of their rank, 133; peculiar characters possessed by, 134; peculiarly diurnal, 136; compared with groups of mammalia, 138; distribution of, 140; large forms of Celebes and Moluccas, 168; large forms of Amboyna, 169; local variation of form, 169; arrangement of, 186; geographical distribution of, 189; of Indo-Malay and Austro-Malay regions, 192; of Java, Sumatra, and Borneo, 193.

PARIDAE, sexual colouring and nidification of, 243.

PASSENGER pigeon, cause of its great numbers, 308.

PATENT inventions, as illustrating classification, 295.

Phacellocera batesii, mimics one of the Anthribidae, 94.

Phalaropus fulicarius, 115, 251.

PHASMIDAE, imitate sticks and twigs, 64; females resembling leaves, 112.

PHYLLIUM, wonderful protective colour and form of, 64.

PHYSALIA, 258.

PIERIDAE, local modification of form in, 172.

PIERIS, females only imitating Heliconidae, 112.

Pieris coronis, 172; eperia, 172.

Pieris pyrrha, 113.

PICIDAE, sexual colouring and nidification of, 242.

PIPRIDAE, sexual colouring and nidification of, 245.

PITTIDAE, 253.

Pliocerus equalis, 101; P. elapoides, P. euryzonus, 102.

Paeciloderma terminale, 93.

POLARITY, Forbes' theory of, 17, 45.

POLYMORPHISM, 145; illustration of, 157.

POPULATION of species, law of, 28; does not permanently increase, 29; not determined by abundance of offspring, 29; checks to, 30; difference in the case of cats and rabbits explained, 32.

PREVISION, a case of, 122.

PRIONITURUS, 196.

PROTECTION, various modes in which animals obtain it, 69-71, 258; greater need of, in female insects and birds, 113.

PROTECTIVE colouring, theory of, 65.

PSITTACI (Parrots), sexual colouring and nidification of, 242.

PTEROSAURIA, 298.

PTYCHODERES, 94.

RACES, or subspecies, 160; of man, origin of, 319.

REDBREAST and woodpigeon, protective colouring of, 53, 54.

REPRESENTATIVE groups, 9; of Trogons, butterflies, &c., 12.

REPTILES, protective colouring of, 54.

RHAMPHASTIDAE, sexual colouring and nidification of, 242.

RHINOCEROS, 299.

RIVER system, as illustrating self-adaptation, 276.

ROSES, Mr. Baker on varieties of, 165.

RUDIMENTARY organs, 23.

SALVIN, Mr. Osbert, on a case of bird mimicry, 107.

Saturnia pavonia-minor, protective colouring of larva of, 63.

SATYRIDAE, probable means of protection of, 176.

SAUROPTERYGIA, 299.

SAVAGES, why they become extinct, 319; undeveloped intellect of, 339, 341; intellect of, compared with that of animals, 341, 343; protect their backs from rain, 346.

SCANSORIAL birds, nests of, 238.

SCAPHURA, 98.

SCISSIROSTRUM, 165.

SCOPULIPEDES, brush-legged bees, 91.

SCUDDER, Mr., on fossil insects, 301.

SCUTELLERIDAE, mimicked by Longicorns, 96.

Sesia bombiliformis, 90.

SESIIDAE, mimic Hymenoptera, 90.

SEXES, comparative importance of, in different classes of animals, 111; diverse habits of, 156.

SEXUAL SELECTION, 156; its normal action to develop colour in both sexes, 247; among birds, 283.

SIDGWICK, Mr. A., on protective colouring of moths, 62.

SIMOCYONIDAE, 300.

SITTA, sexual colouring and nidification of, 243.

SITTELLA, sexual colouring and nidification of, 243.

SNAKES, mimicry among, 101.

SONG of birds, instinctive or imitative, 220.

SPECIES, law of population of, 28; abundance or rarity of, dependent on the adaptation to conditions, 33; definition of, 141, 161; the range and constancy of, 143; extreme variation in, 163, 164.

SPEED of animals, limits of, 292.

Sphecia craboniforme, 90.

Sphecomorpha chalybea, 96.

SPHEGIDAE, mimicked by flies, 97.

SPIDERS, which mimic ants, 98; and flower buds, 99.

Spilosoma menthastri, 88.

STAINTON, Mr., on moths rejected by turkeys, 78, 88.

STALACHTIS, a genus of Erycinidae, the object of mimicry, 84.

STINGING insects generally conspicuously coloured, 72.

STREPTOCITTA, 196.

STURNIDAE, sexual colouring and nidification of, 244.

STURNOPASTOR, 239.

ST. HELENA, 10.

Streptolabis hispoides, 93.

STRUGGLE for existence, 28, 33.

SURVIVAL of the fittest, law of, stated, 33; its action in determining colour, 67.

SWAINSON'S circular and quinarian theory, 45.

SYLVIADAE, sexual colouring and nidification of, 245.

SYNAPTA, 258.

TACHORNIS phoenicobea, 228.

Tachyris hombronii, 172; ithome, 172; lycaste, 172; lyncida, 172; nephele, 172; nero, 172; zarinda, 172.

TANAGRIDAE, sexual colouring and nidification of, 245.

TAPIR, 299.

TELEPHORI, similar colouring of two sexes, 114.

TEMPERATE and cold climates favourable to civilization, 318.

THECODONTIA, 299.

THERATES, mimicked by Heteromera, 95.

Thyca descombesi, 172; hyparete, 172; rosenbergii, 172; zebuda, 172.

TIGER, adaptive colouring of, 52.

TIMES newspaper on Natural Selection, 296.

TOOLS, importance of, to man, 314.

TREE FROGS, probable mimicry by, 103.

TRICONDYLA, 97.

TRIMEN, Mr., on rank of the Papilionidae, 136.

TRISTRAM, Rev. H., on colours of desert animals, 50.

Trochilium tipuliforme, 90.

TROGONIDAE, sexual colouring and nidification of, 241.

TROPICAL birds often green, 52.

TROPICS, most favourable to production of perfect adaptation among animals, 68; not favourable to growth of civilization, 318.

TROPIDORHYNCHUS mimicked by orioles, 104.

TRUTHFULNESS of some savages, 353; not to be explained on utilitarian hypothesis, 354.

TURDIDAE, sexual colouring and nidification of, 245.

TURNIX, 115, 251.

TYNDALL, Professor, on origin of consciousness, 361.

UPUPIDAE, sexual colouring and nidification of, 241.

USEFUL and useless variations, 34.

UTILITY, importance of the principle of, 47, 127.

VARIABILITY, simple, 144.

VARIATIONS, useful and useless, 34; laws of, 143, 266; as influenced by locality, 166; of size, 168; universality of, 287-291; are there limits to, 291; of domestic dogs, 293; of pigeons, 293.

VARIETIES, instability of, supposed to prove the permanent distinctness of species, 26; if superior will extirpate original species, 36; its reversion then impossible, 37; of domesticated animals may partially revert, 38, 40; inconvenience of using the term, 161.

VERTEBRATA, mimicry among, 99.

VOICE of man, not explained by natural selection, 350.

VOLUCELLA, species of mimic bees, 75, 98.

WALSH, Mr., on dimorphism, of Papilio turnus, 153.

WEAPONS and tools, how they affect man's progress, 314.

WEEVILS often resemble small lumps of earth, 58.

WEIR, Mr. Jenner, on a moth refused by birds, 89; on beetles refused by birds, 93; on caterpillars eaten and rejected by birds, 119.

WESTWOOD, Professor, objections to theory of mimicry, 108.

WHITE colour in domesticated and wild animals, 66.

WILD and domesticated animals, essential differences of, 38-41.

WILL really exerts force, 367; probably the primary source of force, 368.

WOOD, Mr. T. W., on orange-tip butterfly, 59.

WOODCOCKS and Snipes, protective colouring of, 53.

WOODPECKERS, why scarce in England, 32.

XANTHIA, autumnal colours of these moths, 62.

ZEBRAS, 299.

Transcriber's Notes & Errata The following entries were added to the Table of Contents. In Chapter IV. The Malayan Papilionidae, or Swallow-tailed Butterflies, as illustrative of the Theory of Natural Selection.: Arrangement and Geographical Distribution of the Malayan Papilionidae Range of the Groups of Malayan Papilionidae In Chapter VI. The Philosophy of Birds' Nests.: How young Birds may learn to build Nests. Missing page number 94 supplied for the entry "Phacellocera batesii, mimics one of the Anthribidae," in the index. The following words were found in both hyphenated and unhyphenated forms (incidence in parentheses). Co-existing (2) Coexisting (1) Fly-catcher (1) Flycatcher (2) sea-weed (2) seaweed (1) bull-dog (1) bulldog (1) The following typographical errors have been corrected: Error Correction sparrrow sparrow unwieldly unwieldy it its Perphaps Perhaps confimation confirmation Pharoahs Pharaohs receptable receptacle occured occurred that that than that

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