ST. MARY'S COLLEGE LIBRARY, 1926 . v ON THE GENESIS OF SPECIES. BY ST. GEOEGE MIVART, F. K. S. REV. JAMES A. GRANT BEQUEST TO ST. MARY'S COLLEGE LIBRARY, 1926 NEW YOEK: D. APPLETON AND COMPANY, 649 & 651 BROADWAY. 1871. TO SIE HENRY HOLLAND, BART., M. D., R K. S., D. C. L., ETC., ETC. MY DEAR SIB HENRY: In giving myself the pleasure to dedicate, as I now do, this work to you, it is not my intention to identify you with any views of my own advocated in it. I simply avail myself of an opportunity of paying a tribute of esteem and regard to my earliest scientific friend — the first to encourage me in pursuing the study of Nature. I remain, My dear Sir Henry, Ever faithfully yours, ST. GEORGE MIVART. 7 NORTH BANK, REGENT'S PARK, December 8, 1870. CONTENTS. CHAPTER I. INTRODUCTORY. The Problem of the Genesis of Species stated.— Nature of its Probable Solution.— Im- portance of the Question. — Position here defended. — Statement of the DARWINIAN THEOBY.— Its Applicability to Details of Geographical Distribution ; to Eudimentary Structures ; to Homology ; to Mimicry, etc. — Consequent Utility of the Theory. — Its Wide Acceptance.— Reasons for this, other than, and in Addition to, its Scientific Value.— Its Simplicity.— Its Bearing on Religious Questions.— Odium Theologicum, and Odium Antitheologicwm. — The Antagonism supposed by many to exist be- tween it and Theology neither necessary nor universal. — Christian Authorities in favor of Evolution.— Mr. Darwin's "Animals and Plants under Domestication."— Difficulties of the Darwinian Theory enumerated . . . . p. 13 CHAPTER II. THK INCOMPETENCY OF "NATURAL SELECTION" TO AOCOUNT FOB THE IN- CIPIENT STAGES OF USEFUL STRUCTURES. Mr. Darwin supposes that Natural Selection acts by Slight Variations.— These must be useful at once.— Difficulties as to the Giraffe ; as to Mimicry ; as to the Heads of Flat-fishes ; as to the Origin and Constancy of the Vertebrate Limbs ; as to Whale- bone; as to the Young Kangaroo; as to Sea-urchins; as to Certain Processes of Metamorphosis ; as to the Mammary-gland ; as to Certain Ape Characters ; as to CONTENTS. the Eattlesnake and Cobra ; as to the Process of Formation of the Eye and Ear , as to the Fully -developed Condition of the Eye and Ear; as to the Voice; as to Shell- fish; as to Orchids; as to Ants.— the Necessity for the Simultaneous Modification of Many Individuals.— Summary and Conclusion . . . . p. 35 CHAPTER III. THE COEXISTENCE OF CLOSELY-SIMILAR STRUCTURES OF DIVERSE ORIGIN. Chances against Concordant Variations.— Examples of Discordant Ones. — Concordant Variations not unlikely on a non-Darwinian Evolutionary Hypothesis. — Placental and Implacental Mammals. — Birds and Eeptiles. — Independent Origins of Similar Sense Organs. — The Ear.— The Eye. — Other Coincidences. — Causes besides Natural Selection produce Concordant Variations in Certain Geographical Eegions. — Causes besides Natural Selection produce Concordant Variations in Certain Zoological and Botanical Groups. — There are Homologous Parts not genetically related. — Harmony in respect of the Organic and Inorganic Worlds.— Summary and Conclusion . p. 76 CHAPTER IV. MINUTE AND GRADUAL MODIFICATIONS. There are Difficulties as to Minute Modifications, even if not fortuitous.— Examples of Sudden and Considerable Modifications of Different Kinds.— Prof. Owen's View. — Mr. Wallace.— Prof. Huxley. — Objections to Sudden Changes.— Labyrinthodont.— Potto.— Cetacea.— As to Origin of Bird's Wing.— Tendrils of Climbing Plants.— Animals once supposed to be Connecting Links. — Early Specialization of Structure. — Macrauchenia. — Glyptodon. — Sabre-toothed Tiger. — Conclusion . . p. Ill CHAPTER V. AS TO SPECIFIC STABILITY. What is meant by the Phrase "Specific Stability;" such Stability to be expected a priori, or else Considerable Changes at once. — Rapidly-increasing Difficulty of in- tensifying Eace Characters ; Alleged Causes of this Phenomenon ; probably an In- CONTENTS. 7 ternal Cause co5perates. — A Certain Definiteness in Variations. — Mr. Darwin ad- mits the Principle of Specific Stability in Certain Cases of Unequal Variability.— The Goose.— The Peacock.— The Guinea-fowl.— Exceptional Causes of Variation under Domestication. — Alleged Tendency to Eeversion. — Instances. — Sterility of Hybrids.— Prepotency of Pollen of Same Species, but of Different Race.— Mortality in Young Gallinaceous Hybrids. — A Bar to Intermixture exists somewhere. — Guinea-pigs.— Summary and Conclusion . . . . . p. 127 CHAPTER VI. •>•. SPECIES AND TIME. Two Relations of Species to Time.— No Evidence of Past Existence of Minutely- intermediate Forms when such might be expected a priori.— Bats, Pterodac- tyls, Dinosauria, and Birds. — Ichthyosauria, Chelonia, and Anoura. — Horse An- cestry.—Labyrinthodonts and Trilobites.— Two Subdivisions of the Second Rela- tion of Species to Time.— Sir William Thomson's Views.— Probable Period re- quired for Ultimate Specific Evolution from Primitive Ancestral Forms. — Geo- metrical Increase of Time required for Rapidly-multiplying Increase of Structural Differences.— Proboscis Monkey.— Time required for Deposition of Strata neces- sary for Darwinian Evolution.— High Organization of Silurian Forms of Life.— Absence of Fossils in Oldest Rocks. — Summary and Conclusion . . p. 142 CHAPTEK VH. SPECIES AND SPACE. The Geographical Distribution of Animals presents Difficulties.— These not Insur- mountable hi themselves ; harmonize with other Difficulties. — Fresh-water Fishes. —Forms common to Africa and India; to Africa and South America; to China and Australia; to North America and China; to New Zealand and South America; to South America and Tasmania; to South America and Australia. — Pleurodont Lizards. — Insectivorous Mammals. — Similarity of European and South American Frogs.— Analogy between European Salmon and Fishes of New Zea- land, etc.— An Ancient Antarctic Continent probable.— Other Modes of accounting for Facts of Distribution. — Independent Origin of Closely-similar Forms. — Con- clusion . . . . . . . . . . p. 158 8 CONTENTS. CHAPTER VIII. HOMOLOGIES. Animals made up of Parts mutually related in Various Ways.— What Homology is. — Its Various Kinds. — Serial Homology. — Lateral Homology. — Vertical Homology. -Mr. Herbert Spencer's Explanations.— An Internal Power necessary, as shown by Facts of Comparative Anatomy.— Of Teratology.— M. St. Hilaire.— Prof. Burt Wild- er.—Foot-wings.— Facts of Pathology.— Mr. .fames Paget— Dr. William Budd.— The Existence of such an Internal Power of Individual Development diminishes the Improbability of an Analogous Law of Specific Origination. . . p. 169 CHAPTER IX. EVOLUTION AND ETHICS. The Origin of Morals an Inquiry not foreign to the Subject of this Book.— Modern Utilitarian View as to that Origin.— Mr. Darwin's Speculation as to the Origin of the Abhorrence of Incest.— Cause assigned by him insufficient.— Care of the Aged and Infirm opposed by "Natural Selection;" also Self-abnegation and Asceti- cism.—Distinctness of the Ideas " Eight " and " Useful."— Mr. John Stuart Mill. — Insufficiency of "Natural Selection" to account for the Origin of the Distinction between Duty and Profit— Distinction of Moral Acts into "Material" and "For- mal."—No Ground for believing that Formal Morality exists in Brutes.— Evidence that it does exist in Savages. — Facility with which Savages may be misunder- stood.—Objections as to Diversity of Customs.— Mr. Button's Review of Mr. Her- bert Spencer. — Anticipatory Character of Morals. — Sir John Lubbock's Explana- tion.—Summary and Conclusion . . . . . . p. 202 CHAPTER X. PANGENESIS. A Provisional Hypothesis supplementing "Natural Selection."— Statement of the Hy- pothesis.—Difliculty as to Multitude of Gemmules.— As to Certain Modes of Re- production.— As to Formations without the Requisite Gemmules. — Mr. Lewes and Prof. Delpino.— Difficulty as to Developmental Force of Gemmules.— As to then- Spontaneous Fission. — Pangenesis and Vitalism. — Paradoxical Reality. — Pangene- sis scarcely superior to Anterior Hypothesis. — Buffon. — Owen. — Herbert Spen- cer.—" Gemmules " as Mysterious as " Physiological Units." — Conclusion . p. 223 CONTENTS. 9 CHAPTER XI. SPECIFIC GENESIS. Review of the Statements and Arguments of Preceding Chapters. — Cumulative Argu- ment against Predominant Action of "Natural Selection.1"— Whether any Thing positive as well as negative can be enunciated. — Constancy of Laws of Nature does not necessarily imply Constancy of Specific Evolution.— Possible Exceptional Sta- bility of Existing Epoch.— Probability that an Internal Cause of Change exists.— Innate Powers somewhere must be accepted. — Symbolism of Molecular Action under Vibrating Impulses.— Prof. Owen's Statement.— Statement of the Author's View.— It avoids the Difficulties which oppose " Natural Selection."— It harmon- izes Apparently Conflicting Conceptions.— Summary and Conclusion . p. 235 CHAPTER XII. THEOLOGY AND EVOLUTION. Prejudiced Opinions on the Subject.—" Creation " sometimes denied from Prejudice. — The Unknowable.— Mr. Herbert Spencer's Objections to Theism; to Creation.— Meanings of Term " Creation."— Confusion from not distinguishing between "Pri- mary " and " Derivative " Creation. — Mr. Darwin's Objections. — Bearing of Chris- tianity on the Theory of Evolution.— Supposed Opposition, the Kesult of a Miscon- ception.—Theological Authority not opposed to Evolution.— St. Augustine.— St. Thomas Aquinas. — Certain Consequences of Want of Flexibility of Mind. — Eeason and Imagination. — The First Cause and Demonstration. — Parallel between Chris- tianity and Natural Theology.— What Evolution of Species is.— Prof. Agassiz.— In- nate Powers must be recognized.— Bearing of Evolution on Eeligious Belief.— Prof. Huxley.— Prof. Owen.— Mr. Wallace.— Mr. Darwin.— A priori Conception of Di- vine Action.— Origin of Man.— Absolute Creation and Dogma.— Mr. Wallace's View. —A Supernatural Origin for Man's Body not necessary.— Two Orders of Being in Man.— Two Modes of Origin.— Harmony of the Physical, Hyperphysical, and Super- natural.— Reconciliation of Science and Religion as regards Evolution. — Conclu- sion p. 259 INDEX p. 808 LIST OF ILLUSTEATIONS. Leaf Butterfly in flight and repose (from Mr. A. Wallaces " Malay's Archi- pelago") 43 Walking-Leaf Insect 47 Pleuronectidae, with the peculiarly placed eye in different positions (from Dr. Traquair's paper in Lirm. Soc. Trans., 1865) . . . .49,180 Mouth of Whale (from Prof. Owen's " Odontography") ... 53 Four plates of Baleen seen obliquely from within (from Prof. Owen's " Odon- tography") ......... 54 Dugong 54, 189 Echinus Or Sea Urchin . . • . . . . . 56, 181 Pedicellariae of Echinus vary much enlarged ..... 59 Rattlesnake 62 Cobra (from Sir Andrew Smith's " Soutliern Africa'"') ... 63 Wingbones of Pterodactyl, Bat, and Bird (from Mr. Andrew Murray's " Geographical Distribution of Mammate") . . . .77,144,111 Skeleton of Flying-Dragon .78,172 Centipede (from a specimen in the Museum of the Royal College of Sur- geons) . . . 79, 173 Teeth of Urotrichus and Perameles ...... 82 The Archeopteryx (from Prof. Owen's " Anatomy of Vertebrata "") . . 86, 146 Cuttle-Fish 5 88, 155 Skeleton of Ichthyosaurus 92,121,146,191 Cytheridea Torosa (from Messrs. Brady and Robertson's paper in Ann. and Mag. of Nat. Hist., 1870) 93 A Polyzoon, with BirdVhead processes ...... 94 Bird's-head processes greatly enlarged ...... 95 Antechinus Minutissimus and Mus Delicatulus (from Mr. Andrew Murray*.* " Geographical Distribution of Mammals") .... 96 12 LIST OF ILLUSTRATIONS. RAM Outlines of Wings of Butterflies of Celebes compared with those of allied spe- cies elsewhere ......... 100 Great Shielded Grasshopper ....... 103 The Six-shafted Bird of Paradise 104 The Long-tailed Bird of Paradise 105 The Red Bird of Paradise 106 Horned Flies ......... 107 The Magnificent Bird of Paradise 107 (The above seven figwes are from Mr. A. Wallace's " Malay ArcM- pelago"') Much enlarged horizontal Section of the Tooth of a Labyrinthodon (from Prof. Owen's " OdontograpJiy ") . . . . . . .118 Hand of the Potto (fromUfe) 119 Skeleton of Plesiosaurus : 120,141,192 The Aye-Aye (from Trans, of Zool. Soc.) 122 Dentition of Sabre-toothed Tiger (from Prof. Owen's " OdontograpJiy ") . 125 Trilobite 149,185 Inner side of Lower Jaw of Pleurodont Lizard (from Prof. Owen's " Odontog- rapJiy'") 162 Solenodon (from Berlin Trans.) . . . . . . .163 Tarsal Bones of Galago and Cheirogaleus (from Proc. Zool. Soc.) . . 173 Squilla 174 Parts of the Skeleton of the Lobster 175 Spine of Galago Menu (from Proo. Zool. Soc.) 176 Vertebra of Axolotl (from Proc. Zool. Soc.) 179 Annelid undergoing spontaneous fission . . . . . 188, 226 Aard-Yark (Orycteropus capensis) ... . . 188 Pangolin (Manis) ......... 189 Skeleton of Manus and Pes of a Tailed Batrachian (from Prof. Gegeribaiir's " Tarsus and Corpus"') ....... 192 Flexor Muscles of Hand of Nycticetus (from Proc. Zool. Soc.) . . .194 The Fibres of Corti 296 11493 THE GENESIS OF SPECIES. CHAPTER I. INTRODUCTORY. The Problem of the Genesis of Species stated.— Nature of its Probable Solution.— Im- portance of the Question.— Position here defended.— Statement of the DARWINIAN THEORY.— Its Applicability to Details of Geographical Distribution ; to Rudimentary Structures ; to Homology ; to Mimicry, etc. — Consequent Utility of the Theory. — Its Wide Acceptance.— Eeasons for this, other than, and in Addition to, its Scientific Yalue.— Its Simplicity.— Its Bearing on Religious Questions.— Odium Theologicwm and Odlwm, Antttheologicum. — The Antagonism supposed by many to exist be- tween it and Theology neither necessary nor universal. — Christian Authorities in iavor of Evolution. — Mr. Darwin's " Animals and Plants under Domestication.11 — Difficulties of the Darwinian Theory enumerated. THE great problem which has so long exercised the minds of naturalists, namely, that concerning the origin of different kinds of animals and plants, seems at last to be fairly on the road to receive — perhaps at no very dis- tant future — as satisfactory a solution as it can well have. But the problem presents peculiar difficulties. The birth of a " species " has often been compared with that of an " individual." The origin, however, of even an individ- ual animal or plant (that which determines an embryo to evolve itself — as, e. g., a spider rather than a beetle, a rose- plant rather than a pear) is shrouded in obscurity. A fortiori must this be the case with the origin of a " species." Moreover, the analogy between a "species" and an 14 THE GENESIS OF SPECIES. [CHAP. "individual" is a very incomplete one. The word "indi- vidual " denotes a concrete whole with a real, separate, and distinct existence. The word " species," on the other hand, denotes a peculiar congeries of characters, innate powers and qualities, and a certain nature realized indeed in indi- viduals, but having no separate existence, except ideally as a thought in some mind. Thus the birth of a " species " can only be compared metaphorically, and very imperfectly, with that of an " indi- vidual." Individuals, as individuals, actually and directly produce and bring forth other individuals ; but no " congeries of characters," no "common nature" as such, can directly bring forth another " common nature," because, per se, it has no existence (other than ideal) apart from the individ- uals in which it is manifested. The problem then is, " By what combination of natural laws does a new ' common nature ' appear upon the scene of realized existence ? " i. e., how is an individual embody- ing such new characters produced ? For the approximation we have of late made toward the solution of this problem, we are mainly indebted to the in- valuable labors and active brains of Charles Darwin and Alfred Wallace. Nevertheless, important as have been the impulse and direction given by those writers to both our observations and speculations, the solution will not (if the views here advocated are correct) ultimately present that aspect and character with which it has issued from the hands of those writers. Neither, most certainly, will that solution agree in ap- pearance or substance with the more or less crude concep- tions which have been put forth by most of the opponents of Messrs. Darwin and Wallace. Rather, judging from the more recent manifestations of I.] INTRODUCTORY. 15 thought on opposite sides, we may expect the development of some tertiwn quid — the resultant of forces coming from different quarters, and not coinciding in direction with any one of them. As error is almost always partial truth, and so consists in the exaggeration or distortion of one verity by the sup- pression of another which qualifies and modifies the former, we may hope, by the synthesis of the truths contended for by various advocates, to arrive at the one conciliating reality. Signs of this conciliation are not wanting : opposite scientific views, opposite philosophical conceptions, and opposite religious beliefs, are rapidly tending, by their vig- orous conflict, to evolve such a systematic and comprehen- sive view of the genesis of species as will completely harmonize with the teachings of science, philosophy, and religion. To endeavor to add one stone to this temple of concord, to try and remove a few of the misconceptions and mutual misunderstandings which oppose harmonious action, are the aim and endeavor of the present work. This aim it is hoped to attain, not by shirking difficulties, but analyzing them, and by endeavoring to dig down to the common root which supports and unites diverging stems of truth. It cannot but be a gain when the laborers in the three fields above mentioned, namely, science, philosophy, and religion, shall- fully recognize this harmony. Then the energy too often spent in futile controversy, or withheld through prejudice, may be profitably and reciprocally exer- cised for the mutual benefit of all. Remarkable is the rapidity with which an interest in the question of specific origination has spread. But a few years ago it scarcely occupied the minds of any but natural- ists. Then the crude theory put forth by Lamarck, and by his English interpreter, the author of the " Vestiges of Ore- 16 THE GENESIS OF SPECIES. [CHAP. ation," had rather discredited than helped on a belief in organic evolution — a belief, that is, in new kinds being pro- duced from older ones by the ordinary and constant opera- tion of natural laws. Now, however, this belief is widely diffused. Indeed, there are few drawing-rooms where it is not the subject of occasional discussion, and artisans and school-boys have their views as to the permanence of or- ganic forms. Moreover, the reception of this doctrine tends actually, though by no means necessarily, to be accompa- nied by certain beliefs with regard to quite distinct and very momentous subject-matter. So that the question of the " Genesis of Species " is not only one of great interest, but also of much importance. But though the calm and thorough consideration of this matter is at the present moment exceedingly desirable, yet the actual importance of the question itself as to its conse- quences in the domain of theology has been strangely exag- gerated by many, both of its opponents and supporters. This is especially the case with that form of the evolution theory which is associated with the name of Mr. Darwin ; and yet neither the refutation nor the demonstration of that doctrine would be necessarily accompanied by the results which are hoped for by one party and dreaded by another. The general theory of evolution has indeed for some time past steadily gained ground, and it may be safely pre- dicted that the number of facts which can be brought for- ward in its support will, in a few years, be vastly augment- ed. But the prevalence of this theory need alarm no one, for it is, without any doubt, perfectly consistent with strict- est and most orthodox Christian theology. Moreover, it is not altogether without obscurities, and cannot yet be con- sidered as fully demonstrated. The special Darwinian hypothesis, however, is beset with certain scientific difficulties, which must by no means I.] INTRODUCTORY. 17 be ignored, and some of which, I venture to think, are ab- solutely insuperable. What Darwinism or " Natural Selec- tion " is, will be shortly explained ; but, before doing so, I think it well to state the object of this book, and the view taken up and defended in it. It is its object to maintain the position that " Natural Selection " acts, and indeed must act, but that still, in order that we may be able to account for the production of known kinds of animals and plants, it requires to be supplemented by the action of some other natural law or laws as yet undiscovered.1 Also, that the consequences which have been drawn from Evolution, whether exclusively Darwinian or not, to the prejudice of religion, by no means follow from it, and are in fact illegiti- mate. The Darwinian theory of " Natural Selection " may be shortly stated thus : 2 Every kind of animal and plant tends to increase in numbers in a geometrical progression. Every kind of animal and plant transmits a general like- ness, with individual differences, to its offspring. Every individual may present minute variations of any kind and in any direction. Past time has been practically infinite. Every individual has to endure a very severe struggle for existence, owing to the tendency to geometrical increase of all kinds of animals and plants, while the total animal and vegetable population (man and his agency excepted) remains almost stationary. 1 In the last edition of the "Origin of Species" (1869) Mr. Darwin himself admits that "Natural Selection" has not been the exclusive means of modification, though he still contends it has been the most im- portant one. 2 See Mr. Wallace's recent work, entitled " Contributions to the The- ory of Natural Selection," where, at p. 302, it ia very well and shortly stated. 18 THE GENESIS OF SPECIES. [CHAP. Thus, every variation of a kind tending to save the life of the individual possessing it, or to enable it more surely to propagate its kind, will in the long-run be preserved, and will transmit its favorable peculiarity to some of its offspring, which peculiarity will thus become intensified till it reaches the maximum degree of utility. On the other hand, individuals presenting unfavorable peculiarities will be ruthlessly destroyed. The action of this law of " Natural Selection " may thus be well represented by the convenient expression, " survival of the fittest." 8 Now, this conception of Mr. Darwin's is, perhaps, the' most interesting theory, in relation to natural science, which has been promulgated during the present century. Remarkable, indeed, is the way in which it groups together such a vast and varied series of biological 4 facts, and even paradoxes, which it appears more or less clearly to explain, as the following instances will show. By this theory of "Natural Selection," light is thrown on the more singular facts relating to the geographical distribution of animals and plants ; for example, on the resemblance between the past and present inhabitants of different parts of the earth's surface. Thus in Australia remains have been found of creatures closely allied to kangaroos and other kinds of pouched beasts, which in the present day exist nowhere but in the Australian region. Similarly in South America, and nowhere else, are found sloths, and armadillos, and in that same part of the world have been discovered bones of ani- mals different indeed from existing sloths and armadillos, but yet much more nearly related to them than to any other kinds whatever. Such coincidences between the existing and antecedent geographical distribution of forms are nu- 3 " Natural Selection " is happily so termed by Mr. Herbert Spencer in his " Principles of Biology." 4 Biology is the science of life. It contains zoology, or the science of animals, and botany, or that of plants. I.] INTRODUCTORY. 19 merous. Again, " Natural Selection " serves to explain the circumstance that often in adjacent islands we find ani- mals closely resembling, and appearing to represent, each other ; while, if certain of these islands show signs (by depth of surrounding sea or what not) of more ancient separation, the animals inhabiting them exhibit a corre- sponding divergence.5 The explanation consists in rep- resenting the forms inhabiting the islands as being the modified descendants of a common stock, the modification being greatest where the separation has been the most pro- longed. " Rudimentary structures " also receive an explanation by means of this theory. These structures are parts which are apparently functionless and useless where they occur, but which represent similar parts of large size and func- tional importance in other animals. Examples of such " ru- dimentary structures" are the fcetal teeth of whales, and of the front part of the jaw of ruminating quadrupeds. These fcetal structures are minute in size, and never cut the gum, but are reabsorbed without ever coming, into use, while no other teeth succeed them or represent them in the adult condition of those animals. The mammary glands of all male beasts constitute another example, as also does the wing of the apteryx — a New Zealand bird utterly incapable of flight, and with the wing in a quite rudimentary condi- tion (whence the name of the animal). Yet this rudiment- ary wing contains bones which are miniature representa- tives of the ordinary wing-bones of birds of flight. Now, the presence of these useless bones and teeth is explained if they may be considered as actually being the inherited diminished representatives of parts of large size and func- tional importance in the remote ancestors of these various animals. 5 For very interesting examples, see Mr. Wallace's "Malay Archi- pelago." 20 THE GENESIS OF SPECIES. [CHAP Again, the singular facts of " homology " are capable of a similar explanation. " Homology " is the name applied to the investigation of those profound resemblances which have so often been found to underlie superficial differences between animals of very different form and habit. Thus man, the horse, the whale, and the bat, all have the pec- toral limb, whether it be the arm, or fore-leg, or paddle, or wing, formed on essentially the same type, though the num- ber and proportion of parts may more or less differ. Again, the butterfly and the shrimp, different as they are in ap- pearance and mode of life, are yet constructed on the same common plan, of which they constitute diverging manifesta- tions. No a priori reason is conceivable why such simi- larities should be necessary, but they are readily explicable on the assumption of a genetic relationship and affinity be- tween the animals in question, assuming, that is, that they are the modified descendants of some ancient form — their common ancestor. That remarkable series of changes which animals under- go before they attain their adult condition, which is called their process of development, and during which they more or less closely resemble other animals during the early stages of the same process, has also great light thrown on it from the same source. The question as to the singularly complex resemblances borne by every adult animal and plant to a certain number of other animals and plants — re- semblances by means of which the adopted zoological and botanical systems of classification have been possible — finds its solution in a similar manner, classification becoming the expression of a genealogical relationship. Finally, by this theory — and as yet by this alone — can any explanation be given of that extraordinary phenomenon which is meta- phorically termed mimicry. Mimicry is a close and striking, yet superficial resemblance borne by some animal or plant to some other, perhaps very different, animal or plant. The L] INTRODUCTORY. 21 "walking leaf" (an insect belonging to the grasshopper and cricket order) is a well-known and conspicuous instance of the assumption by an animal of the appearance of a vegetable structure (see illustration on p. 47) ; and the bee, fly, and spider orchids, are familiar examples of a converse resemblance. Birds, butterflies, reptiles, and even fish, seem to bear in certain instances a similarly striking re- semblance to other birds, butterflies, reptiles, and fish, of altogether distinct kinds. The explanation of this matter which " Natural Selection " offers, as to animals, is that cer- tain varieties of one kind have found exemption from per- secution in consequence of an accidental resemblance which such varieties have exhibited to animals of another kind, or to plants ; and that they were thus preserved, and the de- gree of resemblance was continually augmented in their descendants. As to plants, the explanation offered by this theory might, perhaps, be, that varieties of plants, which presented a certain superficial resemblance in their flowers to insects, have thereby been helped to propagate their kind, the visit of certain insects being useful or indispen- sable to the fertilization of many flowers. We have thus a whole series of important facts which " Natural Selection " helps us to understand and coordi- nate. And not only are all these diverse facts strung to- gether, as it were, by the theory in question ; not only does it explain the development of the complex instincts of the beaver, the cuckoo, the bee, and the ant, as also the dazzling brilliancy of the humming-bird, the glowing tail and neck of the peacock, and the melody of the nightin- gale ; the perfume of the rose and the violet, the bril- liancy of the tulip and the sweetness of the nectar of flow- ers ; not only does it help us to understand all these, but serves as a basis of future research and of inference from the known to the unknown, and it guides the investigator to the discovery of new facts which, when ascertained, it 22 THE GENESIS OF SPECIES. [CHAP. seems also able to coordinate." Nay, " Natural Selection " seems capable of application not only to the building up of the smallest and most insignificant organisms, but even of extension beyond the biological domain altogether, so as possibly to have relation to the stable equilibrium of the solar system itself, and even of the whole sidereal uni- verse. Thus, whether this theory be true or false, all lov- ers of natural science should acknowledge a deep debt of gratitude to Messrs. Darwin and Wallace, on account of its practical utility. But the utility of a theory by no means implies its truth. . What do we not owe, for example, to the labors of the Alchemists ? The emission theory of light, again, has been pregnant with valuable results, as still is the Atomic theory, and others which will readily suggest themselves. With regard to Mr. Darwin (with whose name, on ac- count of the noble self-abnegation of Mr. Wallace, the theory is in general exclusively associated), his friends may heartily congratulate him on the fact that he is one of the few exceptions to the rule respecting the non-appreciation of a prophet in his own country. It would be difficult to name another living laborer in the field of physical science who has excited an interest so wide-spread, and given rise to so much praise, gathering round him, as he has done, a chorus of more or less completely acquiescing disciples, themselves masters in science, and each the representative of a crowd of enthusiastic followers. Such is the Darwinian theory of " Natural Selection," such are the more remarkable facts which it is potent to 6 See Miiller's work, " Fur Darwin," lately translated into English by Mr. Dallas. Mr. Wallace also predicts the discovery, in Madagascar, of a hawk-moth with an enormously-long proboscis, and he does this on account of the discovery there of an orchid with a nectary from ten to fourteen inches in length. See Quarterly Journal of Science, October, 1867, and "Natural Selection," p. 275. COLLHOE I.] INTRODUCTORY. 23 explain, and such is the reception it has met with world. A few words now as to the reasons for the very wide-spread interest it has awakened, and the keenness with which the theory has been both advocated and com- bated. The important bearing it has on such an extensive range of scientific facts, its utility, and the vast knowledge and great ingenuity of its promulgator, are enough to ac- count for the heartiness of its reception by those learned in natural history. But quite other causes have concurred to produce the general and higher degree of interest felt in the theory besides the readiness with which it harmonizes with biological facts. These latter could only be appreci- ated by physiologists, zoologists, and botanists ; whereas the Darwinian theory, so novel and so startling, has found a cloud of advocates and opponents beyond and outside the world of physical science. In the first place, it was inevitable that a great crowd of half-educated men and shallow thinkers should accept with eagerness the theory of " Natural Selection," or rath- er what they think to be such (for few things are more re- markable than the way in which it has been misunder- stood), on account of a certain characteristic it has in com- mon with other theories ; which should not be mentioned in the same breath with it, except, as now, with the accom- paniment of protest and apology. We refer to its remark- able simplicity, and the ready way in which phenomena the most complex appear explicable by a cause for the comprehension of which laborious and persevering efforts are not required, but which may be represented by the sim- ple phrase " survival of the fittest." With nothing more than this, can, on the Darwinian theory, all the most intri- cate facts of distribution and affinity, form and color, be accounted for ; as well the most complex instincts and the most admirable adjustments, such as those of the human 24 THE GENESIS OF SPECIES. [CHAP eye and ear. It is in great measure, then, owing to this supposed simplicity, and to a belief in its being yet easier and more simple than it is, that Darwinism, however imper- fectly understood, has become a subject for general conver- sation, and has been able thus widely to increase a certain knowledge of biological matters; and this excitation of interest, in quarters where otherwise it would have been en-, tirely wanting, is an additional motive for gratitude on the part of naturalists to the authors of the new theory. At the same time it must be admitted that a similar " simpli- city"— the apparently easy explanation of complex phe- nomena— also constitutes the charm of such matters as hy- dropathy and phrenology, in the eyes of the unlearned or half-educated public. It is indeed the charm of all those seeming " short-cuts " to knowledge, by which the labor of mastering scientific details is spared to those who yet be- lieve that without such labor they can attain all the most valuable results of scientific research. It is not, of course, for a moment meant to imply that its " simplicity " tells at all against " Natural Selection," but only that the actual or supposed possession of that quality is a strong reason for the wide and somewhat hasty acceptance of the theory, whether it be true or not. In the second place, it was inevitable that a theory ap- pearing to have very grave relations with questions of the last importance and interest to man, that is, with ques- tions of religious belief, should call up an army of assail- ants and defenders. Nor have the supporters of the theory much reason, in many cases, to blame the more or less unskilful and hasty attacks of adversaries, seeing that those attacks have been in great part due to the unskilful and perverse advocacy of the cause on the part of some of its adherents. If the odium theologicum has inspired some of its opponents, it is undeniable that the odium, an- titheologicum has possessed not a few of its supporters. I.] INTRODUCTORY. 25 It is true (and in appreciating some of Mr. Darwin's ex- pressions it should never be forgotten) that the theory has been both at its first promulgation and since vehemently attacked and denounced as unchristian, nay, as necessarily atheistic ; but it is not less true that it has been made use of as a weapon of offence by irreligious writers, and has been again and again, especially in Continental Europe, thrown, as it were, in the face of believers, with sneers and contumely. When we recollect the warmth with which what he thought was Darwinism was advocated by such a writer as Prof. Vogt, one cause of his zeal was not far to seek — a zeal, by-the-way, certainly not " accord- ing to knowledge ; " for few conceptions could have been more conflicting with true Darwinism than the theory he formerly maintained, but has since abandoned, viz., that the men of the Old World were descended from African and Asiatic apes, while, similarly, the American apes were the progenitors of the human beings of the New World. The cause of this palpable error in a too eager disciple one might hope was not anxiety to snatch up all or any arms available against Christianity, were it not for the tone un- happily adopted by this author. But it is unfortunately quite impossible to mistake his meaning and intention, for he is a writer whose offensiveness is gross, while it is some- times almost surpassed by an amazing shallowness. Of course, as might fully be expected, he adopts and repro- duces the absurdly trivial objections to absolute morality drawn from differences in national customs.7 And he seems to have as little conception of the distinction be- tween " formally " moral actions and those which are only " materially " moral, as of that between the verbum men- tale and the verbum oris. As an example of his onesided- ness, it may be remarked that he compares the skulls of the 7 " Lectures on Man," translated by the Anthropological Society, 1864, p. 229. 2 26 THE GENESIS OF SPECIES. [CHAP. American monkeys (Cebus apella and C. albifrons) with the intention of showing that man is of several distinct species, because skulls of different men are less alike than are those of these two monkeys ; and he does this regard- less of how the skulls of domestic animals (with which it is far more legitimate to compare races of men than with wild kinds), e. g., of different dogs or pigeons, tell precisely in the opposite direction. Regardless also of the fact that perhaps no genus of monkeys is in a more unsatisfactory state as to the determination of its different kinds than the genus chosen by him for illustration. This is so much the case that J. A. Wagner (in his supplement to Schreber's great work on Beasts) at first included all the kinds in a single species. As to the strength of his prejudice and his regrettable coarseness, one quotation will be enough to display both. Speaking of certain early Christian missionaries, he says : 8 " It is not so very improbable that the new religion, before which the flourishing Roman civilization relapsed into a state of barbarism, should have been introduced by people in whose skulls the anatomist finds simious characters so well devel- oped, and in which the phrenologist finds the organ of ven- eration so much enlarged. I shall, in the meanwhile, call these simious narrow skulls of Switzerland ' Apostle skulls,' as I imagine that in life they must have resembled the type of Peter the Apostle, as represented in Byzantine-Nazarene art." In face of such a spirit, can it be wondered at that dis- putants have grown warm ? Moreover, in estimating the vehemence of the opposition which has been offered, it should be borne in mind that the views defended by religious writers are, or should be, all-important in their eyes. They could not be expected to view with equanimity the destruc- tion in many minds of "theology, natural and revealed, 8 " Lectures on Man," p. 378. REV. JAMES A. GRANT BEQUEST TO ST. MARY'S COLLEGE LIBRARY, I.] INTRODUCTORY. 27 psychology, and metaphysics ; " nor to weign with calm and frigid impartiality arguments which seemed to them to be fraught with results of the highest moment to mankind, and therefore imposing on their consciences strenuous opposi- tion as a first duty. Cool, judicial impartiality in them would have been a sign perhaps of intellectual gifts, but also of a more important deficiency of generous emotion. It is easy to complain of the onesidedness of many of those who oppose Darwinism in the interest of orthodoxy ; but not at all less patent is the intolerance and narrow- mindedness of some of those who advocate it, avowedly or covertly, in the interest of heterodoxy. This hastiness of rejection or acceptance, determined by ulterior consequences believed to attach to " Natural Selection," is unfortunately in part to be accounted for by some expressions and a cer- tain tone to be found in Mr. Darwin's writings. That his expressions, however, are not always to be construed liter- ally is manifest. His frequent use metaphorically of the expressions, "contrivance," for example, and "purpose," has elicited, from the Duke of Argyll and others, criticisms which fail to tell against their opponent, because such ex- pressions are, in Mr. Darwin's writings merely figurative — metaphors, and nothing more. It may be hoped, then, that a similar looseness of ex- pression will account for passages of a directly opposite tendency to that of his theistic metaphors. Moreover, it must not be forgotten that he frequently uses that absolutely theological term, " the Creator," and that he has retained in all the editions of his " Origin of Species" an expression which has been much criticised. He speaks " of life, with its several powers, having been originally breathed by the Creator into a few forms, or into one."9 This is merely mentioned in justice to Mr. Darwin, and by no means because it is a position which this 9 See 5th edit., 1869, p. 579. 28 THE GENESIS OF SPECIES. [CHAP. book is intended to support. For, from Mr. Darwin's usual mode of speaking, it appears that by such divine action he means a supernatural intervention, whereas it is here con- tended that throughout the whole process of physical evo- lution— the first manifestation of life included — supernatu- ral action is assuredly not to be looked for. Again, in justice to Mr. Darwin, it may be observed that he is addressing the general public, and opposing the ordinary and common objections of popular religionists, who have inveighed against " Evolution " and " Natural Selec- tion " as atheistic, impious, and directly conflicting with the dogma of creation. Still, in so important a matter, it is to be regretted that he did not take the trouble to distinguish between such merely popular views and those which repose upon some more venerable authority. Mr. John Stuart Mill has replied to similar critics, and shown that the assertion that his philosophy is irreconcilable with theism is unfounded ; and it would have been better if Mr. Darwin had dealt in the same manner with some of his assailants, and shown the futility of certain of their objections when viewed from a more elevated religious stand-point. Instead of so doing, he seems to adopt the narrowest notions of his opponents, and, far from endeavoring to expand them, appears to wish to indorse them, and to lend to them the weight of his author- ity. It is thus that Mr. Darwin seems to admit and assume that the idea of " creation " necessitates a belief in an in- terference with, or dispensation of, natural laws, and that " creation " must be accompanied by arbitrary and unorderly phenomena. None but the crudest conceptions are placed by him to the credit of supporters of the dogma of creation, and it is constantly asserted that they, to be consistent, must offer " creative fiats " as explanations of physical phe- nomena, and be guilty of numerous other such absurdities. It is impossible, therefore, to acquit Mr. Darwin of at least I.] INTRODUCTORY. 29 a certain carelessness in this matter ; and the result is, he has the appearance of opposing ideas which he gives no clear evidence of having ever fully appreciated. He is far from being alone in this, and perhaps merely takes up and reiterates, without much consideration, assertions previously assumed by others. Nothing could be further from Mr. Darwin's mind than any, however small, intentional misrep- resentation ; and it is therefore the more unfortunate that he should not have shown any appreciation of a position op- posed to his own other than that gross and crude one which he combats so superfluously — that he should appear, for a moment, to be one of those, of whom there are far too many, who first misrepresent their adversary's view and then elab- orately refute it ; who, in fact, erect a doll utterly incapable of self-defence, and then, with a flourish of trumpets and many vigorous strokes, overthrow the helpless dummy they had previously raised. This is what many do who more or less distinctly oppose theism in the interests, as they believe, of physical science ; and they often represent, among other things, a gross and narrow anthropomorphism as the necessary consequence of views opposed to those which they themselves advocate. Mr. Darwin and others may perhaps be excused if they have not devoted much time to the study of Christian phi- losophy ; but they have no right to assume or accept with- out careful examination, as an unquestioned fact, that in that philosophy there is a necessary antagonism between the two ideas, " creation " and " evolution," as applied to organic forms. It is notorious and patent to all who choose to seek, that many distinguished Christian thinkers have accepted and do accept both ideas, i. e., both " creation " and " evo- lution." As much as ten years ago, an eminently Christian writer observed : " The creationist theory does not necessitate the 30 THE GENESIS OF SPECIES. [CHAP. perpetual search after manifestations of miraculous powers and perpetual ' catastrophes.' Creation is not a miraculous interference with the laws of Nature, but the very institu- tion of those laws. Law and regularity, not arbitrary in- tervention, was the patristic ideal of creation. With this notion, they admitted without difficulty the most surprising origin of living creatures, provided it took place by law. They held that when God said, ' Let the waters produce,' * Let the earth produce,' He conferred forces on the ele- ments of earth and water, which enabled them naturally to produce the various species of organic beings. This power, they thought, remains attached to the elements throughout all time." 10 The same writer quotes St. Augustine and St. Thomas Aquinas, to the effect that, " in the institution of Nature we do not look for miracles, but for the laws of Na- ture." u And, again, St. Basil,18 speaks of the continued operation of natural laws in the production of all organ- isms. So much for writers of early and mediaeval times. As to the present day, the author can confidently affirm that there are many as well versed in theology as Mr. Darwin is in his own department of natural knowledge, who would not be disturbed by the thorough demonstration of his theory. Nay, they would not even be in the least painful- ly affected at witnessing the generation of animals of com- plex organization by the skilful artificial arrangement of natural forces, and the production, in the future, of a fish, by means analogous to those by which we now produce urea. And this because they know that the possibility of such phenomena, though by no means actually foreseen, has yet 10 The Rambler, March, 1860, vol. xii., p. 372. 11 " In prima institutione naturae non quseritur miraculum, sed quid natura rerum habeat, ut Augustinus dicit, lib. ii., sup. Gen. and lit. c. ]." (St. Thomas, Sura. I86. Ixvii. 4, ad 3.) 12 " Hexaem." Horn, ix., p. 81. I.] INTRODUCTORY. 31 been fully provided for in the old philosophy centuries be- fore Darwin, or even before Bacon, and that their place in the system can be at once assigned them without even dis- turbing its order or marring its harmony. Moreover, the old tradition in this respect has never been abandoned, however much it may have been ignored or neglected by some modern writers. In proof of this it may be observed that perhaps no post-mediaeval theologian has a wider reception among Christians throughout the world than Suarez, who has a separate section 13 in opposi- tion to those who maintain the distinct creation of the vari- ous kinds — or substantial forms — of organic life. But the consideration of this matter must be deferred for the present, and the question of evolution, whether Dar- winian or other, be first gone into. It is proposed, after that has been done, to return to this subject (here merely alluded to), and to consider at some length the bearing of " Evolution," whether Darwinian or non-Darwinian, upon " Creation and Theism." Now we will revert simply to the consideration of the theory of " Natural Selection " itself. Whatever may have hitherto been the amount of ac- ceptance that this theory has met with, all, I think, anti- cipated that the appearance of Mr. Darwin's large and care- ful work on " Animals and Plants under Domestication " could but further increase that acceptance. It is, however, somewhat problematical how far such anticipations will be realized. The newer book seems to add after all but little in support of the theory, and to leave most, if not all, its difficulties exactly where they were. It is a question, also, whether the hypothesis of " Pangenesis " 14 may not be 13 Suarez, Metaphysica. Edition Vives. Paris, 1868. Vol. I. Dis- putatio xv., § 2. 14 " Pangenesis " is the name of the new theory proposed by Mr. Darwin, in order to account for various obscure physiological facts, such, 32 THE GENESIS OF SPECIES. [CHAP. found rather to encumber than to support the theory it was intended to subserve. However, the work in question treats only of domestic animals, and probably the next in- stalment will address itself more vigorously and directly to the difficulties which seem to us yet to bar the way to a complete acceptance of the doctrine. If the theory of Natural Selection can be shown to be quite insufficient to explain any considerable number of im- portant phenomena connected with the origin of species, that theory, as the explanation, must be considered as pro- visionally discredited. If other causes than Natural (including sexual) Selec- tion can be proved to have acted — if variation can in any cases be proved to be subject to certain determinations in special directions by other means than Natural Selection, it then becomes probable, a priori, that it is so in others, and that Natural Selection depends upon, and only supple- ments, such means, which conception is opposed to the pure Darwinian position. Now it is certain, a priori, that variation is obedient to some law, and therefore that " Natural Selection " itself must be capable of being subsumed into some higher law ; and it is evident, I believe, a posteriori, that Natural Se- lection is, at the very least, aided and supplemented by some other agency. Admitting, then, organic and other evolution, and that new forms of animals and plants (new species, genera, etc.) e. g., as the occasional reproduction, by individuals, of parts which they have lost ; the appearance in offspring of parental, and sometimes of re- mote ancestral, characters, etc. It accounts for these phenomena by supposing that every creature possesses countless indefinitely-minute organic atoms, termed "gemmules," which atoms are supposed to be generated in every part of every organ, to be in constant circulation about the body, and to have the power of reproduction. Moreover, atoms from every part are supposed to be stored in the generative prod- ucts. I.] INTRODUCTORY. 33 have from time to time been evolved from preceding ani- mals and plants, it follows, if the views here advocated are true, that this evolution has not taken place by the action of " Natural Selection " alone, but through it (among other influences) aided by the concurrent action of some other nat- ural law or laws, at present undiscovered ; and probably that the genesis of species takes place partly, perhaps mainly, through laws which may be most conveniently spoken of as special powers and tendencies existing in each organism ; and partly through influences exerted on each by surrounding conditions and agencies organic and inor- ganic, terrestrial and cosmical, among which the " survival of the fittest " plays a certain but subordinate part. The theory of " Natural Selection " may (though it need not) be taken in such a way as to lead men to regard the present organic world as formed, so to speak, accidentally, beautiful and wonderful as is confessedly the hap-hazard result. The same may perhaps be said with regard to the system advocated by Mr. Herbert Spencer, who, however, also relegates " Natural Selection " to a subordinate role. The view here advocated, on the other hand, regards the whole organic world as arising and going forward in one harmonious development similar to that which displays it- self in the growth and action of each separate individual organism. It also regards each such separate organism as the expression of powers and tendencies not to be accounted for by " Natural Selection " alone, or even by that together with merely the direct influence of surrounding conditions. The difficulties which appear to oppose themselves to the reception of " Natural Selection " or " the survival of the fittest," as the one explanation of the origin of spe- cies, have no doubt been already considered by Mr. Dar- win. Nevertheless, it may be worth while to enumerate them, and to state the considerations which appear to give them weight ; and there is no doubt but that a naturalist 34 THE GENESIS OF SPECIES. [CHAP. so candid and careful as the author of the theory in ques- tion, will feel obliged, rather than the reverse, by the sug- gestion of all the doubts and difficulties which can be brought against it. What is to be brought forward may be summed up as follows : That " Natural Selection " is incompetent to account for the incipient Stages of useful structures. That it does not harmonize with the coexistence of closely-similar structures of diverse origin. That there are grounds for thinking that specific dif- ferences may be developed suddenly instead of gradually. That the opinion that species have definite though very different limits to their variability is still tenable. That certain fossil transitional forms are absent, which might have been expected to be present. That some facts of geographical distribution supple- ment other difficulties. That the objection drawn from the physiological dif- ference between " species " and " races " still exists unre- futed. That there are many remarkable phenomena in organic forms upon which " Natural Selection " throws no light whatever, but the explanations of which, if they could be attained, might throw light upon specific origination. Besides these objections to the sufficiency of " Natural Selection," others may be brought against the hypothesis of " Pangenesis," which, professing as it does to explain great difficulties, seems to do so by presenting others not less great — almost to be the explanation of obscurum per obscurius. II.] INCIPIENT STRUCTURES. 35 CHAPTER II. THE INCOMPETENCY OF "NATURAL SELECTION COUNT FOB THE INCIPIENT STAGES OF USEFUL STRUCT- URES. Mr. Darwin supposes that Natural Selection acts by Slight Variations.— These must be useful at once. — Difficulties as to the Giraffe ; as to Mimicry ; as to the Heads of Flat-fishes ; as to the Origin and Constancy of the Vertebrate Limbs ; as to Whale- bone ; as to the Young Kangaroo ; as to Sea-urchins ; as to certain Processes of Metamorphosis ; as to the Mammary -gland ; as to certain Ape Characters ; as to the Kattlesnake and Cobra ; as to the Process of Formation of the Eye and Ear , as to the Fully-developed Condition of the Eye and Ear ; as to the Voice ; as to Shell- fish ; as to Orchids ; as to Ants. — the Necessity for the Simultaneous Modification of Many Individuals. — Summary and Conclusion. " NATURAL Selection," simply and by itself, is potent to explain the maintenance or the further extension and development of favorable variations, which are at once suf- ficiently considerable to be useful from the first to the indi- vidual possessing them. But Natural Selection utterly fails to account for the conservation and development of the minute and rudimentary beginnings, the slight and infini- tesimal commencements of structures, however useful those structures may afterward become. Now, it is distinctly enunciated by Mr. Darwin, that the spontaneous variations upon which his theory depends are individually slight, minute, and insensible. He says,1 " Slight individual differences, howrever, suffice for the work, and are probably the sole differences which are effec- tive in the production of new species." And again, after 1 "Animals and Plants under Domestication," vol. ii., p. 192 36 THE GENESIS OF SPECIES. [CHAP. mentioning the frequent sudden appearances of domestic varieties, he speaks of " the false belief as to the similarity of natural species in this respect." 8 In his work on the " Origin of Species," he also observes, " Natural Selection acts only by the preservation and accumulation of small inherited modifications." 3 And " Natural Selection, if it be a true principle, will banish the belief ... of any great and sudden modification in their structure." 4 Finally, he adds, " If it could be demonstrated that any complex organ existed, which could not possibly have been formed by nu- merous, successive, slight modifications, my theory would absolutely break down." ' Now the conservation of minute variations in many instances is, of course, plain and intelligible enough; such e. g., as those which tend to promote the destructive facul- ties of beasts of prey on the one hand, or to facilitate the flight or concealment of the animals pursued on the other ; provided always that these minute beginnings are of such a kind as really to have a certain efficiency, however small, in favor of the conservation of the individual possessing them ; and also provided that no unfavorable peculiarity in any other direction accompanies and neutralizes, in the struggle for life, the minute favorable variation. But some of the cases which have been brought for- ward, and which have met with very general acceptance, s.eem less satisfactory when carefully analyzed than they at first appear to be. Among these we may mention " the neck of the giraffe." At first sight it would seem as though a better exam- ple in support of " Natural Selection " could hardly have been chosen. Let the fact of the occurrence of occasional severe droughts in the country which that animal has in- 2 " Animals and Plants under Domestication," vol. ii., p. 414. 3 "Origin of Species," 5th edit., 1869, p. 110. * Ibid., p. 111. 6 Ibid., p. 227. II.] INCIPIENT STRUCTURES. 37 habited be granted. In that case, when the ground vege- tation has been consumed, and the trees alone remain, it is plain that at such times only those individuals (of what we assume to be the nascent giraffe species) which were able to reach high up would be preserved, and would become the parents of the following generation, some individuals of which would, of course, inherit that high-reaching power which alone preserved their parents. Only the high-reach- ing issue of these high-reaching individuals would again, cceteris paribus, be preserved at the next drought, and would again transmit to their offspring their still loftier stature ; and so on, from period to period, through seons of time, all the individuals tending to revert to the ancient shorter type of body, being ruthlessly destroyed at the oc- currence of each drought. (1.) But against this it may be said, in the first place, that the argument proves too much ; for, on this supposi- tion, many species must have tended to undergo a similar modification, and we ought to have at least several forms, similar to the giraffe, developed from different Ungulata.6 A careful observer of animal life, who has long resided in South Africa, explored the interior, and lived in the giraffe country, has assured the author that the giraffe has powers of locomotion and endurance fully equal to those possessed by any of the other Ungulata of that continent. It would seem, therefore, that some of these other Ungulates ought to have developed in a similar manner as to the neck, under pain of being starved, when the long neck of the giraffe was in its incipient stage. To this criticism it has been objected that different kinds of animals are preserved, in the struggle for life, in very different ways, and even that " high reaching " may be at- 6 The order Ungulata contains the hoofed beasts ; that is, all oxen, deer, antelopes, sheep, goats, camels, hogs, the hippopotamus, the differ- ent kinds of rhinoceros, the tapirs, horses, asses, zebras, quaggas, etc. 38 THE GENESIS OF SPECIES. [CHAP. tained in more modes than one — as, for example, by the trunk of the elephant. This is, indeed, true, but then none of the African Ungulata 7 have, nor do they appear ever to have had, any proboscis whatsoever; nor have they ac- quired such a development as to allow them to rise on their hind-limbs and graze on trees in a kangaroo attitude, nor a power of climbing, nor, as far as known, any other modifi- cation tending to compensate for the comparative shortness of the neck. Again, it may perhaps be said that leaf-eating forms are exceptional, and that therefore the struggle to attain high branches would not affect many Ungulates, But surely, when these severe droughts necessary for the theory occur, the ground vegetation is supposed to be exhausted ; and, indeed, the giraffe is quite capable of feed- ing from off the ground. So that, in these cases, the other Ungulata must have taken to leaf-eating or have starved, and thus must have had any accidental long-necked varieties favored and preserved exactly as the long-necked varieties of the giraffe are supposed to have been favored and pre- served. The argument as to the different modes of preservation has been very well put by Mr. Wallace,8 in reply to the objection that " color, being dangerous, should not exist in Nature." This objection appears similar to mine ; as I say that a giraffe neck, being jieedful, there should be many animals with it, while the objector noticed by Mr. Wallace says, " A dull color being needful, all animals should be so colored." And Mr. Wallace shows in reply how porcupines, tortoises, and mussels, very hard-coated bombadier beetles, stinging insects, and nauseous-tasted caterpillars, can afford to be brilliant by the various means of active defence or passive protection they possess, other than obscure colora- 7 The elephants of Africa and India, with their extinct allies, consti- tute the order Probosciclea, and do not belong to the Ungulata. 8 See " Natural Selection," pp. 60-75. II.] INCIPIENT STRUCTURES. 39 tion. He says : " The attitudes of some insects may also protect them, as the habit of turning up the tail by the harmless rove-beetles (Staphylinidae), no doubt leads other animals, besides children, to the belief that they can sting. The curious attitude assumed by sphinx caterpillars is prob- ably a safeguard, as well as the blood-red tentacles which can suddenly be thrown out from the neck by the caterpil- lars of all the true swallow-tailed butterflies." But, because many different kinds of animals can elude the observation or defy the attack of enemies in a great variety of ways, it by no means follows that there are any similar number and variety of ways for attaining vegetable food in a country where all such food, other than the lofty branches of trees, has been for a time destroyed. In such a country we have a number of vegetable-feeding Un- gulates, all of which present minute variations as to the length of the neck. If, as Mr. Darwin contends, the natural selection of these favorable variations has alone lengthened the neck of the giraffe by preserving it during droughts ; similar variations, in similarly feeding forms, at the same times, ought similarly to have been preserved and so length- ened the neck of some other Ungulates by similarly pre- serving them during the same droughts. (2.) It may be also objected, that the power of reaching upward, acquired by the lengthening of the neck and legs, must have necessitated a considerable increase in the entire size and mass of the body (larger bones requiring stronger and more voluminous muscles and tendons, and these again necessitating larger nerves, more capacious blood- vessels, etc.), and it is very problematical whether the dis- advantages thence arising would not, in times of scarcity, more than counterbalance the advantages. For a considerable increase in the supply of food would be requisite on account of this increase in size and mass, while at the same time there would be a certain decrease 40 THE GENESIS OF SPECIES. [CHAP. in strength ; for, as Mr. Herbert Spencer says,9 " It is de- monstrable that the excess of absorbed over expended nu- triment must, other things equal, become less as the size of an animal becomes greater. In similarly-shaped bodies, the masses vary as the cubes of the dimensions ; whereas the strengths vary as the squares of the dimensions." . . . " Supposing a creature which a year ago was one foot high, has now become two feet high, while it is unchanged in proportions and structure — what are the necessary con- comitant changes that have taken place in it ? It is eight times as heavy ; that is to say, it has to resist eight times the strain which gravitation puts on its structure; and in producing, as well as in arresting, every one of its move- ments, it has to overcome eight times the inertia. Mean- while, the muscles and bones have severally increased their contractile and resisting powers, in proportion to the areas of their transverse sections ; and hence are severally but four times as strong as they were. Thus, while the creature has doubled in height, and while its ability to overcome forces has quadrupled, the forces it has to overcome have grown eight times as great. Hence, to raise its body through a given space, its muscles have to be contracted with twice the intensity, at a double cost of matter ex- pended." Again, as to the cost at which nutriment is dis- tributed through the body, and effete matters removed from it, " Each increment of growth being added at the periphery of an organism, the force expended in the transfer of mat- ter must increase in a rapid progression — a progression more rapid than that of the mass." There is yet another point. Vast as may have been the time during which the process of evolution has continued, it is, nevertheless, not infinite. Yet, as every kind, on the Darwinian hypothesis, varies slightly but indefinitely in every organ and every part of every organ, how very gen- 9 "Principles of Biology," vol. i., p. 122. II.] INCIPIENT STRUCTURES. 41 erally must favorable variations as to the length of the neck have been accompanied by some unfavorable variation in some other part, neutralizing the action of the favorable one, the latter, moreover, only taking effect during these periods of drought ! How often must not individuals, fa- vored by a slightly-increased length of neck, have failed to enjoy the elevated foliage which they had not strength or endurance to attain ; while other individuals, exceptionally robust, could struggle on yet further till they arrived at vegetation within their reach ! However, allowing this example to pass, many other in- stances will be found to present great difficulties. Let us take the cases of mimicry among lepidoptera and other insects. Of this subject Mr. Wallace has given a most interesting and complete account,10 showing in how many and strange instances this superficial resemblance by one creature to some other quite distinct creature acts as a safe- guard to the first. One or two instances must here suffice. In South America there is a family of butterflies, termed Ileliconidce, which are very conspicuously colored and slow in flight, and yet the individuals abound in prodigious num- bers, and take no precautions to conceal themselves, even when at rest, during the night. Mr. Bates (the author of the very interesting work " The Naturalist on the River Amazons," and the discoverer of " Mimicry ") found that these conspicuous butterflies had a very strong and disa- greeable odor ; so much so that any one handling them and squeezing them, as a collector must do, has his fingers stained and so infected by the smell, as to require time and much trouble to remove it. It is suggested that this unpleasant quality is the cause of the abundance of the Heliconidae ; Mr. Bates and other observers reporting that they have never seen them at- 10 See " Natural Selection," chap, iii., p. 45. 42 THE GENESIS OF SPECIES. [CHAP. tacked by the birds, reptiles, or insects, which prey upon other lepidoptera. Now it is a curious fact that very different South Amer- ican butterflies put on, as it were, the exact dress of these offensive beauties and mimic them even in their mode of flight. In explaining the mode of action of this protecting re- semblance Mr. Wallace observes : " " Tropical insectivorous birds very frequently sit on dead branches of a lofty tree, or on those which overhang forest-paths, gazing intently around, and darting off at intervals to seize an insect at a considerable distance, with which they generally return to their station to devour. If a bird began by capturing the slow-flying conspicuous Heliconidae, and found them always so disagreeable that it could not eat them, it would after a very few trials leave off catching them at all ; and their whole appearance, form, coloring, and mode of flight, is so peculiar, that there can be little doubt birds would soon learn to distinguish them at a long distance, and never waste any time in pursuit of them. Under these circum- stances, it is evident that any other butterfly of a group which birds were accustomed to devour, would be almost equally well protected by closely resembling a Heliconia externally, as if it acquired also the disagreeable odor ; always supposing that there were only a few of them among a great number of Heliconias." " The approach in color and form to the Heliconidae, however, would be at the first a positive, though perhaps a slight, advantage ; for although at short distances this va- riety would be easily distinguished and devoured, yet at a longer distance it might be mistaken for one of the uneat- able group, and so be passed by and gain another day's life, which might in many cases be sufficient for it to lay a quantity of eggs and leave a numerous progeny, many of 11 Loc. cit, p. 80. II.] INCIPIENT STRUCTURES. which would inherit the peculiarity which had safeguard of their parent." LEAF BUTTERFLY IN FLIGHT AND BEPOSE. (From Mr. Wallaces "Malay Archipelago:11) As a complete example of mimicry Mr. Wallace refers 44 THE GENESIS OF SPECIES. [CHAP, to a common Indian butterfly. He says : ia " But the most wonderful and undoubted case of protective resemblance in a butterfly, which I have ever seen, is that of the common Indian Kallima inachis, and its Malayan ally, Kallima paralekta. The upper surface of these is very striking and showy, as they are of a large size, and are adorned with a broad band of rich orange on a deep-bluish ground. The under side is very variable in color, so that out of fifty specimens no two can be found exactly alike, but every one of them will be of some shade of ash, or brown, or ochre, such as are found among dead, dry, or decaying leaves. The apex of the upper wings is produced into an acute point, a very common form in the leaves of tropical shrubs and trees, and the lower wings are also produced into a short, narrow tail. Between these two points runs a dark curved line exactly representing the midrib of a leaf, and from this radiate on each side a few oblique lines, which serve to indicate the lateral veins of a leaf. These marks are more clearly seen on the outer portion of the base of the wings, and on the inner side toward the middle and apex, and it is very curious to observe how the usual mar- ginal and transverse striae of the group are here modified and strengthened so as to become adapted for an imitation of the venation of a leaf." ..." But this resemblance, close as it is, would be of little use if the habits of the in- sect did not accord with it. If the butterfly sat upon leaves or upon flowers, or opened its wings so as to expose the upper surface, or exposed and moved its head and antennas as many other butterflies do, its disguise would be of little avail. We might be sure, however, from the analogy of many other cases, that the habits of the insect are such as still further to aid its deceptive garb ; but we are not obliged to make any such supposition, since I myself had the good fortune to observe scores of Kallima, paralekta^ 13 Loc. cit., p. 59. II.] INCIPIENT STRUCTURES. 45 in Sumatra, and to capture many of them, and can vouch for the accuracy of the following details. These butterflies frequent dry forests, and fly very swiftly. They were seen to settle on a flower or a green leaf, but were many times lost sight of in a bush or tree of dead leaves. On such oc- casions they were generally searched for in vain, for while gazing intently at the very spot where one had disappeared, it would often suddenly dart out, and again vanish twenty or fifty yards farther on. On one or two occasions the in- sect was detected reposing, and it could then be seen how completely it assimilates itself to the surrounding leaves. It sits on a nearly upright twig, the wings fitting closely back to back, concealing the antennas and head, which are drawn up between their bases. The little tails of the hind- wing touch the branch, and form a perfect stalk to the leaf, which is supported in its place by the claws of the middle pair of feet, which are slender and inconspicuous. The irregular outline of the wings gives exactly the perspective effect of a shrivelled leaf. We thus have size, color, form, markings, and habits, all combining together to produce a disguise which may be said to be absolutely perfect ; and the protection which it affords is sufficiently indicated by the abundance of the individuals that possess it." Beetles also imitate bees and wasps, as do some Lepi- doptera ; and objects the most bizarre and unexpected are simulated, such as dung and drops of dew. Some insects, called bamboo and walking-stick insects, have a most re- markable resemblance to pieces of bamboo, to twigs and branches. Of these latter insects Mr. Wallace says : 13 " Some of these are a foot long and as thick as one's finger, and their whole coloring, form, rugosity, and the arrange- ment of the head, legs, and antennas, are such as to render them absolutely identical in appearance with dry sticks. They hang loosely about shrubs in the forest, and have the 13 Loc. cit., p. 64. 46 THE GENESIS OF SPECIES. [CHAP. extraordinary habit of stretching out their legs unsymmetri- cally, so as to render the deception more complete." Now let us suppose that the ancestors of these various animals were all destitute of the very special protections they at present possess, as on the Darwinian hypothesis we must do. Let it also be conceded that small deviations from the antecedent coloring or form would tend to make some of their ancestors escape destruction by causing them more or less frequently to be passed over, or mistaken by their persecutors. Yet the deviation must, as the event has shown, in each case be in some definite direction, whether it be toward some other animal or plant, or toward some dead or inorganic matter. But as, according to Mr. Dar- win's theory, there is a constant tendency to indefinite vari- ation, and as the minute incipient variations will be in all directions^ they must tend to neutralize each other, and at first to form such unstable modifications that it is difficult, if not impossible, to see how such indefinite oscillations of infinitesimal beginnings can ever build up a sufficiently ap- preciable resemblance to a leaf, bamboo, or other object, for "Natural Selection" to seize upon and perpetuate. This difficulty is augmented when we consider — a point to be dwelt upon hereafter — how necessary it is that many in- dividuals should be similarly modified simultaneously. This has been insisted on in an able article in the North British Review for June, 1867, p. 286, and the consideration of the article has occasioned Mr. Darwin to make an important modification in his views. u In these case,s of mimicry it seems difficult indeed to im- agine a reason why variations tending in an infinitesimal degree in any special direction should be preserved. All variations would be preserved which tended to obscure the perception of an animal by its enemies, whatever direction those variations might take, and the common preservation w « Origin of Species." 5th edit., p. 104.- II.] INCIPIENT STRUCTURES. of conflicting tendencies would greatly favor their mutual neutralization and obliteration if we may rely on the many cases recently brought forward by Mr. Darwin with regard to domestic animals. Mr. Darwin explains the imitation of some species by others more or less nearly allied to it, by the common origin of both the mimic and the mimicked species, and the conse- THE WALKING-LEAF INSECT quent possession by both (according to the theory of " Pan- genesis ") of gemmules tending to reproduce ancestral characters, which characters the mimic must be assumed first to have lost and then to have recovered. Mr. Darwin says,15 " Varieties of one species frequently mimic distinct species, a fact in perfect harmony with the foregoing cases, 15 "Animals and Plants under Domestication," vol. ii., p. 351. 48 THE GENESIS OF SPECIES. [CHAP. and explicable only on the theory of descent" But this at the best is but a partial and very incomplete explanation. It is one, moreover, which Mr. Wallace does not accept.16 It is very incomplete, because it has no bearing on some of the most striking cases, and of course Mr. Darwin does not pretend that it has. We should have to go back far indeed to reach the common ancestor of the mimicking walking- leaf insect and the real leaf it mimics, or the original pro- genitor of both the bamboo insect and the bamboo itself. As these last most remarkable cases have certainly nothing to do with heredity,17 it is unwarrantable to make use of that explanation for other protective resemblances, seeing that its inapplicability, in certain instances, is so manifest. Again, at the other end of the process it is as difficult to account for the last touches of perfection in the mimicry. Some insects which imitate leaves extend the imitation even to the very injuries on those leaves made by the at- tacks of insects or of fungi. Thus, speaking of one of the walking-stick insects, Mr. Wallace says : 18 " One of these creatures obtained by myself in Borneo ( Ceroxylus lacerar tus) was covered over with foliaceous excrescences of a clear olive-green color, so as exactly to resemble a stick grown over by a creeping moss or jungermannia. The Dyak who brought it me assured me it was grown over with moss, although alive, and it was only after a most mi- nute examination that I could convince myself it was not so." Again, as to the leaf-butterfly, he says : 19 " We come to a still more extraordinary part of the imitation, for we find representations of leaves in every stage of decay, vari- ously blotched, and mildewed, and pierced with holes, and in many cases irregularly covered with powdery black dots, 16 Loc. cit., pp. 109, 110. 17 Heredity is the term used to denote the tendency which there is in offspring to reproduce parental features. 18 Loc. cit,, p. 64. 19 Loc. cit., p. 60. II.] INCIPIENT STRUCTURES. 49 gathered into patches and spots, so closely resembling the various kinds of minute fungi that grow on dead leaves, that it is impossible to avoid thinking at first sight that the butterflies themselves have been attacked by real fungi." Here imitation has attained a development which seems utterly beyond the power of the mere " survival of the. fit- test " to produce. How this double mimicry can impor- tantly aid in the struggle for life seems puzzling indeed, but much more so how the first faint beginnings of the im- itation of such injuries in the leaf can be developed in the animal into such a complete representation of them — a for- tiori how simultaneous and similar first beginnings of imi- tations of such injuries could ever have been developed in several individuals, out of utterly indifferent and indetermi- nate infinitesimal variations in all conceivable directions. Another instance which may be cited is the asymmetrical condition of the heads of the flat-fishes (Pleuronectidas), such as the sole, the flounder, the brill, the turbot, etc. In PLETJBONECTID.E, WITH THE PECULIARLY-PLACED EYE IN DIFFERENT POSITIONS. {From Dr. Traquair's paper in the " Transactions of the Linnean Society, 1865.'') all these fishes the two eyes, which in the young are situ- ated as usual one on each side, come to be placed, in the adult, both on the same side of the head. If this condi- 3 50 THE GENESIS OF SPECIES. [CHAP. tion had appeared at once, if in the hypothetically fortu- nate common ancestor of these fishes an eye had suddenly become thus transferred, then the perpetuation of such a transformation by the action of " Natural Selection " is conceivable enough. Such sudden changes, however, are not those favored by the Darwinian theory, and indeed the accidental occurrence of such a spontaneous transformation is hardly conceivable. But if this is not so, if the transit was gradual, then how such transit of one eye a minute fraction of the journey toward the other side of the head could bene- fit the individual is indeed far from clear. It seems, even, that such an incipient transformation must rather have been injurious. Another point with regard to these flat-fishes is that they appear to be in all probability of recent origin — i. e., geologically speaking. There is, of course, no great stress to be laid on the mere absence of their remains from the secondary strata, nevertheless that absence is notewor- thy, seeing that existing fish families, e. g., sharks (Squa- lidse), have been found abundantly, even dow^n so far as the carboniferous rocks, and traces of them in the Upper Silurian. Another difficulty seems to be the first formation of the limbs of the higher animals. The lowest Vertebrata20 are perfectly limbless, and if, as most Darwinians would prob- ably assume, the primeval vertebrate creature was also apodal, how are the preservation and development of the first rudiments of limbs to be accounted for — such rudi- ments being, on the hypothesis in question, infinitesimal and functionless ? In reply to this, it has been suggested that a mere flat- tening of the end of the body has been useful, such, e. g., as 20 The term " Vertebrata " denotes that large group of animals which are characterized by the possession of a spinal column, commonly known as the " backbone." Such animals are ourselves, together with ah1 beasts, birds, reptiles, frogs, toads, and efts, and also fishes. II.] INCIPIENT STRUCTURES. 51 we see in sea-snakes,21 which may be the rudiment of a tail formed strictly to aid in swimming. Also that a mere rough- ness of the skin might be useful to a swimming animal by holding the water better, that thus minute processes might be selected and preserved, and that, in the same way, these might be gradually increased into limbs. But it is, to say the least, very questionable whether a roughness of the skin, or minute processes, would be useful to a swimming animal ; the motion of which they would as much impede as aid, unless they were at once capable of a suitable and appropriate action, which is against the hypothesis. Again, the change from mere indefinite and accidental processes to two regular pairs of symmetrical limbs, as the result of merely fortuitous, favoring variations, is a step the feasibil- ity of which hardly commends itself to the reason, seeing the very different positions assumed by the ventral fins in different fishes. If the above suggestion made in opposi- tion to the views here asserted be true, then the general constancy of position of the limbs of vertebrata may be considered as due to the position assumed by the primitive rugosities from which those limbs were generated. Clearly only two pairs of rugosities were so preserved and devel- oped, and all limbs (on this view) are descendants of the same two pairs, as all have so similar a fundamental struct- ure. Yet we find in many fishes the pair of fins, which correspond to the hinder limbs of other animals, placed so far forward as to be either on the same level with, or actu- ally in front of, the normally anterior pair of limbs ; and such fishes are from this circumstance called " thoracic," or " jugular " fishes respectively, as the weaver-fishes and the cod. This is a wonderful contrast to the fixity of position of vertebrate limbs generally. If, then, such a change can 21 It is hardly necessary to observe that these " sea-snakes " have no relation to the often-talked-of " sea-serpent." They are small, venomous reptiles, which abound in the Indian seas. THE GENESIS OF SPECIES. [CHAP. have taken place in the comparatively short time occupied by the evolution of these special fish forms, we might cer- tainly expect other and far more bizarre structures would (did not some law forbid) have been developed from other rugosities, in the manifold exigencies of the multitudinous organisms which must (on the Darwinian hypothesis) have been gradually evolved during the enormous period inter- vening between the first appearance of vertebrate life and the present day. Yet with these exceptions, the position of the limbs is constant from the lower fishes up to man, there being always an anterior pectoral pair placed in front of a posterior or pelvic pair when both are present, and in no single instance are there more than these two pairs, MOUTH OP A WHALE. The development of whalebone (baleen) in th& mouth of the whale is another difficulty. A whale's mouth is fur- II.] INCIPIENT STRUCTURES. 53 II nished with very numerous horny plates, which hang down from the palate along each side of the mouth. They thus form two longitudinal series, each plate of which is placed transversely to the long axis of the body, and all are very close together. On depressing the lower lip the free outer edges of these plates come into view. Their inner edges are furnished with numerous coarse hair-like processes, consist- ing of some of the constituent fibres of the horny plates — which, as it were, fray out — and the mouth is thus lined, except below, by a net-work of countless fibres formed by the inner edges of the two series of plates. This net- work acts as a sort of sieve. When the whale feeds it takes into its mouth a great gulp of water, which it drives out again through the intervals of the horny plates of baleen, the fluid thus traversing the sieve of horny fibres, which retains the mi- nute creatures on which these marine mon- sters subsist. Now it is obvious, that if this baleen had once attained such a size and de- velopment as to be at all useful, then its pres- ervation and augmentation within service- able limits would be promoted by " Natural Selection " alone. But how to obtain the FOUR PLATES OF BALEEN SEEN OBLIQUELY FKOM WITHIN. 54 THE GENESIS OF SPECIES. [CHAP. beginning of such useful development ? There are indeed certain animals of exclusively aquatic habits (the dugong and manatee) which also possess more or less horn on the palate, and at first sight this might be taken as a mitiga- tion of the difficulty ; but it is not so, and the fact does not help us one step further along the road : for, in the first place, these latter animals differ so importantly in structure from whales and porpoises that they form an al- together distinct order, and cannot be thought to approxi- mate to the whale's progenitors. They are vegetarians, the whales feed on animals ; the former never have the ribs ar- ticulated in the mode in which they are in some of the lat- ter ; the former have pectoral mammae, and the latter are provided with two inguinal mammary glands, and have the nostrils enlarged into blowers, which the former have not. The former thus constitute the order Sirenia, while the lat- ter belong to the Cetacea. In the second place, the horny matter on the palates of the dugong and manatee has not, even initially, that " strainer " action which is the characteristic function of the Cetacean " baleen." There is another very curious structure, the origin or the disappearance of which it seems impossible to account for on the hypothesis of minute indefinite variations. It is that of the mouth of the young kangaroo. In all mam- mals, as in ourselves, the air-passage from the lungs opens in the floor of the mouth behind the tongue, and in front of the opening of the gullet, so that each particle of food as it is swallowed passes over the opening, but is prevented from falling into it (and thus causing death from choking) by the action of a small cartilaginous shield (the epiglottis), which at the right moment bends back and protects the ori- fice. Now the kangaroo is born in such an exceedingly imperfect and undeveloped condition, that it is quite unable to suck. The mother, therefore, places the minute blind and naked young upon the nipple, and then injects milk II.] INCIPIENT STRUCTURES. 55 into it by means of a special muscular envelope of the mammary gland. Did no special provision exist, the young one must infallibly be choked by the intrusion of the milk into the windpipe. But there is a special provision. The larynx is so elongated that it rises up into the posterior end of the nasal passage, and is thus enabled to give free entrance to the air for the lungs, while the milk passes harmlessly on each side of this elongated larynx, and so safely attains the gullet behind it. Now, on the Darwinian hypothesis, either all mammals descended from marsupial progenitors, or else the marsu- pials sprung from animals having in most respects the or- dinary mammalian structure. On the first alternative, how did " Natural Selection " remove this (at least perfectly innocent and harmless) struct- ure in almost all other mammals, and, having done so, again reproduce it in precisely those forms which alone re- quire it, namely, the Cetacea ? That such a harmless struct- ure need not be removed, any Darwinian must confess, since a structure exists in both the crocodiles and gavials, which enables the former to breathe themselves while drowning the prey which they hold in their mouths. On Mr. Darwin's hypothesis it could only have been developed where useful, therefore not in the gavials (!) which feed on fish, but which yet retain, as we might expect, this, in them, superfluous but harmless formation. On the second alternative, how did the elongated larynx itself arise, seeing that if its development lagged behind that of the maternal structure, the young primeval kanga- roo must be choked ; while, without the injecting power in the mother, it must be starved ? The struggle by the sole action of which such a form was developed must indeed have been severe ! The sea-urchins (Echinus) present us also with structures the origin of which it seems impossible to explain by the 56 THE GENESIS OF SPECIES. [CHAP. action of " Natural Selection " only. These lowly animals belong to that group of the star-fish class (Echinodermata), the species of which possess generally spheroidal bodies, built up of multitudinous calcareous plates, and constitute AN ECHINUS, OK SEA-TJRCUIN. (The spines removed from one-half.) the order Echinoidea. They are also popularly known as sea-eggs. Utterly devoid of limbs, the locomotion of these creatures is effected by means of rows of small tubular suckers (which protrude through pores in the calcareous plates), and by movable spines scattered over the body. Besides these spines and suckers there are certain very peculiar structures, termed " Pedicellariag." Each of these consists of a long slender stalk, ending in three short limbs — or rather jaws — the whole supported by a delicate inter- nal skeleton. The three limbs (or jaws), which start from a common point at the end of the stalk, are in the constant habit of opening and closing together again with a snap- ping action, while the stalk itself sways about. The utility of these appendages is, even now, problematical. It may be that they remove from the surface of the animal's body foreign substances which would be prejudicial to it, and II.] INCIPIENT STRUCTURES. which it cannot otherwise get rid of. But granting this, what would be the utility of the first rudi- mentary beginnings of such structures, and how could such incipient buddings have ever preserved the life of a single Echinus ? It is true that on Darwinian principles the ances- tral form from which the sea-urchin developed was different, and must not be conceived merely as an Echinus devoid of .pedicellariaa ; but this makes the difficulty none the less. It is equally hard to imagine that the first rudiments of such structures could have been useful to any animal from which the Echinus might have been derived. Moreover, not even the sudden development of the snap- ping action could have been beneficial with- out the freely movable stalk, nor could the latter have been efficient without the snap- ping jaws, yet no minute merely indefinite variations could simultaneously evolve these complex coordinations of structure ; to deny this seems to do no less than to affirm a start- ling paradox. Mr. Darwin explains the appearance of some structures, the utility of which is not apparent, by the existence of certain " laws of correlation." By these he means that certain parts or organs of the body are so related to other organs or parts, that when the first are modified by the action of "Natural Selection," or what not, the second are simul- taneously affected, and increase proportionally or possibly so decrease. Examples of such are the hair and teeth in the naked Turkish dog, the general deafness of white cats with blue eyes, the relation between the presence of more or less down on young birds when first hatched, and PEDICELLARIJ3. (Immensely enlarged.) 58 THE GENESIS OF SPECIES. [CHAP. the future color of their plumage," with many others. But the idea that the modification of any internal or external part of the body of an Echinus carries with it the effect of producing elongated, flexible, triradiate, snapping processes, is, to say the very least, fully as obscure and mysterious as what is here contended for, viz., the efficient presence of an unknown internal natural law or laws conditioning the evo- lution of new specific forms from preceding ones, modified by the action of surrounding conditions, by " Natural Se- lection," and by other controlling influences. The same difficulty seems to present itself in other ex- amples of exceptional structure and action. In the same Echinus, as in many allied forms, and also in some more or less remote ones, a very peculiar mode of development exists. The adult is not formed from the egg directly, but the egg gives rise to a creature which swims freely about, feeds, and is even somewhat complexly organized. Soon a small lump appears on one side of its stomach ; this en- larges, and, having established a communication with the exterior, envelops and appropriates the creature's stomach, with which it swims away and develops into the complete adult form, while the dispossessed individual perishes. Again, certain flies present a mode of development equally bizarre, though quite different. In these flies, the grub is, as usual, produced from the ovum, but this grub, instead of growing up into the adult in the ordinary way, undergoes a sort of liquefaction of a great part of its body, while certain patches of formative tissue, which are attached to the ramifying air-tubes, or tracheae (and which patches bear the name of " imaginal disks "), give rise to the legs, wings, eyes, etc., respectively ; and these severally-formed parts grow together, and build up the head and body by their mutual approximation. Such a process is unknown outside the class of insects, and inside that class it is only 22 "Origin of Species," 5th edit, 1869, p. 179. II.] INCIPIENT STRUCTURES. 59 known in a few of the two-winged flies. Now, how " Nat- ural Selection," or any " laws of correlation," can account for the gradual development of such an exceptional process of development — so extremely divergent from that of other insects — seems nothing less than inconceivable. Mr. Dar- win himself " gives an account of a very peculiar and ab- normal mode of development of a certain beetle, the sitaris, as described by M. Fabre. This insect, instead of at first appearing in its grub stage, and then, after a time, putting on the adult form, is at first active and furnished with six legs, two long antennae, and four eyes. Hatched in the nests of bees, it at first attaches itself to one of the males, and then crawls, when the opportunity offers, upon a female bee. When the female bee lays her eggs, the young sitaris springs upon them and devours them. Then, losing its eyes, legs, and antennae, and becoming rudimentary, it sinks into an ordinary grub-like form, and feeds on honey, ultimately undergoing another transformation, reacquiring its legs, etc., and emerging a perfect beetle ! That such a process should have arisen by the accumulation of minute accidental variations in structure and habit, appears to many minds, quite competent to form an opinion on the subject, absolutely incredible. It may be objected, perhaps, that these difficulties are difficulties of ignorance — that we cannot explain them be- cause we do not know enough of the animals. But it is here contended that this is not the case ; it is not that we merely fail to see how " Natural Selection " acted, but that there is a positive incompatibility between the cause as- signed and the results. It will be stated shortly what won- derful instances of coordination and of unexpected utility Mr. Darwin has discovered in orchids. The discoveries are not disputed or undervalued, but the explanation of their origin is deemed thoroughly unsatisfactory— utterly insuf- 23 " Origin of Species," 5th edit., p. 532. 60 THE GENESIS OF SPECIES. [CHAP. ficient to explain the incipient, infinitesimal beginnings of structures which are of utility only when they are consider- ably developed. Let us consider the mammary gland, or breast. Is it conceivable that the young of any animal was ever saved from destruction by accidentally sucking a drop of scarcely nutritious fluid from an accidentally hypertrophied cutaneous gland of its mother ? And, even if one was so, what chance was there of the perpetuation of such a variation ? On the hypothesis of " Natural Selection " itself, we must assume that up to that time the race had been well adapted to the surrounding conditions ; the temporary and accidental trial and change of conditions, which caused the so-sucking young one to be the " fittest to survive " under the supposed cir- cumstances, would soon cease to act, and then the progeny of the mother, with the accidentally hypertrophied, seba- ceous glands, would have no tendency to survive the far outnumbering descendants of the normal ancestral form. If, on the other hand, we assume the change of conditions not to have been temporary but permanent, and also assume that this permanent change of conditions was accidentally synchionous with the change of structure, we have a coin- cidence of very remote probability indeed. But if, again, we accept the presence of some harmonizing law simulta- neously determining the two changes, or connecting the second with the first by causation, then, of course, we re- move the accidental character of the coincidence. Again, how explain the external position of the male sexual glands in certain mammals? The utility of the modification, when accomplished, is problematical enough, and no less so the incipient stages of the descent. As was said in the first chapter, Mr. Darwin explains the brilliant plumage of the peacock or the humming-bird by the action of sexual selection : the more and more bril- liant males being selected by the females (which are thus II.] INCIPIENT STRUCTURES. 61 attracted) to become the fathers of the next generation, to which generation they tend to communicate their own bright nuptial vesture. But there are peculiarities of color and of form which it is exceedingly difficult to account for by any such action. Thus, among apes, the female is no- toriously weaker, and is armed with much less powerful canine tusks than the male. When we consider what is known of the emotional nature of these animals, and the periodicity of its intensification, it is hardly credible that a female would often risk life or limb through her admiration of a trifling shade of color, or an infinitesimally greater though irresistibly fascinating degree of wartiness.24 Yet the males of some kinds of ape are adorned with quite exceptionally brilliant local decoration, and the male orang is provided with remarkable, projecting, warty lumps of skin upon the cheeks. As we have said, the weaker female can hardly be supposed to have developed these by persevering and long-continued selection, nor can they be thought to tend to the preservation of the individual. On the contrary, the presence of this enlarged appendage must occasion a slight increase in the need of nutriment, and in so far must be a detriment, although its detrimental effect would not be worth speaking of except in relation to " Darwinism," according to which, " selection " has acted through unimaginable ages, and has ever tended to sup- press any useless development by the struggle for life.26 24 Mr. A. D. Bartlett, of the Zoological Society, informs me that at these periods female apes admit with perfect readiness the access of any males of different species. To be sure this is in confinement ; but the fact is, I think, quite -conclusive against any such sexual selection in a state of nature as would account for the local coloration referred to. 25 Mr. Darwin, in the last (fifth) edition of "Natural Selection," 1869, p. 102, admits that all sexual differences are not to be attributed to the agency of sexual selection, mentioning the wattle of carrier-pigeons, tuft of turkey-cock, etc. These characters, however, seem less inexplicable by sexual selection than those given in the text. THE GENESIS OF SPECIES. [CHAP. In poisonous serpents, also, we have structures which, at all events, at first sight, seem positively hurtful to those reptiles. Such are the rattle of the rattlesnake, and the expanding neck of the cobra, the former seeming to warn the ear of the intended victim, as the latter warns the eye. It is true we cannot perhaps demonstrate that the victims RATTLESNAKE. are alarmed and warned, but, on Darwinian principles, they certainly ought to be so. For the rashest and most incau- tious of the animals preyed on would always tend to fall victims, and the existing individuals being the long-de- scended progeny of the timid and cautious, ought to have an inherited tendency to distrust, among other things, both II.] INCIPIENT STRUCTURES. 63 " rattling " and " expanding " snakes. As to any power of fascination exercised by means of these actions, the most distinguished naturalists, certainly the most distin- guished erpetologists, entirely deny it, and it is opposed to the careful observations of those known to us.26 COBEA. (Copied, by permission, from Sir Andrew Smith? a '•'•Reptiles of South, Africa") The mode of formation of both the eye and the ear of the highest animals is such that, if it is (as most Darwini- ans assert processes of development to be) a record of the actual steps by which such structures were first evolved in antecedent forms, it almost amounts to a demonstration 26 1 am again indebted to the kindness of Mr. A. D. Bartlett, among others. That gentleman informs me that, so far from any mental emo- tion being produced in rabbits by the presence and movements of snakes, he has actually seen a male and female rabbit satisfy the sexual instinct in that presence, a rabbit being seized by a snake when in cottu. 64 THE GENESIS OF SPECIES. [CHAP. that those steps were never produced by " Natural Selec- tion." The eye is formed by a simultaneous and corresponding ingrowth of one part and outgrowth of another. The skin in front of the future eye becomes depressed, the depres- sion increases and assumes the form of a sac, which changes into the aqueous humor and lens. An outgrowth of brain-substance, on the other hand, forms the retina, while a third process is a lateral ingrowth of connective tissue, which afterward changes into the vitreous humor of the eye. The internal ear is formed by an involution of the in- tegument, and not by an outgrowth of the brain. But tis- sue, in connection with it, becomes in part changed, thus forming the auditory nerve, which places the tegumentary sac in direct communication with the brain itself. Now, these complex and simultaneous coordinations could never have been produced by infinitesimal begin- nings, since, until so far developed as to effect the requi- site junctions, they are useless. But the eye and ear when fully developed present conditions which are hopelessly dif- ficult to reconcile with the mere action of " Natural Selec- tion." The difficulties with regard to the eye had been well put by Mr. Murphy, especially that of the concordant result of visual development springing from different start- ing-points and continued on by independent roads. He says,27 speaking of the beautiful structure of the perfect eye, " The higher the organization, whether of an entire organism or of a single organ, the greater is the number of the parts that cooperate, and the more perfect is their cooperation ; and consequently, the more necessity there is for corresponding variations to take place in all the cooperating parts at once, and the more useless will be any variation whatever unless it is accompanied by correspond- 27 " Habit and Intelligence," vol. i., p. 319. II.] INCIPIENT STRUCTURES. 65 ing variations in the cooperating parts ; while it is obvious that the greater the number of variations which are needed in order to effect an improvement, the less will be the probability of their all occurring at once. It is no reply to this to say, what is no doubt abstractedly true, that what- ever is possible becomes probable, if only time enough be allowed. There are improbabilities so great that the com- mon-sense of mankind treats them as impossibilities. It is not, for instance, in the strictest sense of the word, im- possible that a poem and a mathematical proposition should be obtained by the process of shaking letters out of a box ; but it is improbable to a degree that cannot be distin- guished from impossibility ; and the improbability of ob- taining an improvement in an organ by means of several spontaneous variations, all ' occurring together, is an im- probability of the same kind. If we suppose that any single variation occurs on the average once in m times, the probability of that variation occurring in any individual will be — and suppose that x variations must concur in order to make an improvement, then the probability of the necessary vari- ations all occurring together will be Now suppose, what I think a moderate proposition, that the value of m is 1,000, and the value of x is 10, then — JL _L_ J_- m* ~ iOOO1"0 ~~ 1055' A number about ten thousand times as great as the number of waves of light that have fallen on the earth since histori- cal time began. And it is to be further observed, that no improvement will give its possessor a certainty of surviving 66 THE GENESIS OF SPECIES. [CHAP and leaving offspring, but only an extra chancy the value of which it is quite impossible to estimate." This difficulty is, as Mr. Murphy points out, greatly intensified by the un- doubted fact that the wonderfully complex structure has been arrived at quite independently in beasts on the one hand and in cuttle-fishes on the other; while creatures of the insect and crab division present us with a third and quite separately developed complexity. As to the ear, it would take up too much space to de- scribe its internal structure ; " it must suffice to say that in its interior there is an immense series of minute rod-like bodies, termed fibres of Corti, having the appearance of a key-board, and each fibre being connected with a filament of the auditory nerve, these nerves being like strings to be struck by the keys, i. e., by the fibres of Corti. Moreover, this apparatus is supposed to be a key-board in function as well as in appearance, the vibration of each one fibre giving rise, it is believed, to the sensation of one particular tone, and combinations of such vibrations producing chords. It is by the action of this complex organ, then, that all the wonderful intricacy and beauty of Beethoven and Mozart come, most probably, to be perceived and appreciated. Now, it can hardly be contended that the preservation of any race of men in the struggle for life ever depended on such an extreme delicacy and refinement of the internal ear — a perfection only exercised in the enjoyment and ap- preciation of the most perfect musical performances. How, then, could either the minute incipient stages, or the final perfecting touches of this admirable structure, have been brought about by vague, aimless, and indefinite variations in all conceivable directions of an organ, suitable to en- able the rudest savage to minister to his necessities, but no more? 28 The reader may consult Huxley's " Lessons in Elementary Physi- ology," p. 204. II.] INCIPIENT STRUCTURES. 67 Mr. Wallace " makes an analogous remark with regard to the organ of voice in man — the human larynx. He says of singing : " The habits of savages give no indication of how this faculty could have been developed by Natural Se- lection, because it is never required or used by them. The singing of savages is a more or less monotonous howling, and the females seldom sing at all. Savages certainly never choose their wives for fine voices, but for rude health, and strength, and physical beauty. Sexual selection could not therefore have developed this wonderful power, which only comes into play among civilized people." Reverting once more to beauty of form and color, there is one manifestation of it for which no one can pretend that sexual selection can possibly account. The instance re- ferred to is that presented by bivalve shell-fish.30 Here we meet with charming tints and elegant forms and markings of no direct use to their possessors 31 in the struggle for life, and of no indirect utility as regards sexual selection, for fertilization takes place by the mere action of currents of water, and the least beautiful individual has fully as good a chance of becoming a parent as has the one which is the most favored in beauty of form and color. Again, the peculiar outline and coloration of certain orchids — notably of our own bee, fly, and spider orchids — seem hardly explicable by any action of " Natural Selec- tion." Mr. Darwin says very little on this singular resem- blance of flowers to insects, and what he does say seems hardly to be what an advocate of " Natural Selection " 29 " Natural Selection," p. 350. 30 Bivalve shell-fish are creatures belonging to the oyster, scallop, and cockle group, i. e., to the class Lamellibranchiata. 31 The attempt has been made to explain these facts as owing to " manner and symmetry of growth, and to color being incidental on the chemical nature of the constituents of the shell." But surely beauty depends on some such matters in all cases ! 68 THE GENESIS OF SPECIES. [CHAP. would require. Surely, for minute accidental indefinite va- riations to have built up such a striking resemblance to in- sects, we ought to find that the preservation of the plant, or the perpetuation of its race, depends almost constantly on relations between bees, spiders, and flies respectively and the bee, spider, and fly orchids.38 This process must have continued for ages constantly and perseveringly, and yet what is the fact ? Mr. Darwin tells us, in his worl^ on the " Fertilization of Orchids," that neither the spider nor the fly orchids are much visited by insects, while, with re- gard to the bee orchid, he says, " I have never seen an in- sect visit these flowers." And he shows how this species is even wonderfully and specially modified to effect self- fertilization. In the work just referred to Mr. Darwin gives a series of the most wonderful and minute contrivances by which the visits of insects are utilized for the fertilization of orchids — structures so wonderful that nothing could well be more so, except the attribution of their origin to minute, fortui- tous, and indefinite variation. The instances are too numerous and too long to quote, but in his " Origin of Species " 33 he describes two which must not be passed over. In one ( Coryanthes) the orchid has its lower lip enlarged into a bucket, above which stand two water-secreting horns. These latter replenish the bucket from which, when half-filled, the water overflows by a spout on one side. Bees visiting the flower fall into the bucket and crawl out at the spout. By the peculiar arrangement of the parts of the flower, the first bee which does so car- 32 It, has been suggested in opposition to what is here said, that there is no real resemblance, but that the likeness is "fanciful! " The denial, however, of the fact of a resemblance which has struck so many ob- servers, reminds one of the French philosopher's estimate of facts hostile to his theory — " Tant pis pour les faits ! " 33 Fifth edition, p. 236. II.] INCIPIENT STRUCTURES. 69 ries away the pollen-mass glued to his back, and then when he has his next involuntary bath in another flower, as he crawls out the pollen-mass attached to him comes in con- tact with the stigma of that second flower and fertilizes it. In the other example (Catasetum), when a bee gnaws a certain part of the flower, he inevitably touches a long deli- cate projection, which Mr. Darwin calls the antenna. " This antenna transmits a vibration to a certain membrane, which is instantly ruptured ; this sets free a spring by which the pollen-mass is shot forth like an arrow in the right direc- tion, and adheres by its viscid extremity to the back of the bee ! " Another difficulty, and one of some importance, is pre- sented by those communities of ants which have not only a population of sterile females, or workers, but two distinct and very different castes of such. Mr. Darwin believes that he has got over this difficulty by having found individuals intermediate in form and structure 34 between the two work- ing castes ; others may think that we have in this belief of Mr. Darwin, an example of the unconscious action of vo- lition upon credence. A vast number of difficulties similar to those which have been mentioned might easily be cited — those given, however, may suffice. There remains, however, to be noticed a very important consideration, which was brought forward in the North British Review for June, 1867, p. 286, namely, the neces- sity for the simultaneous modification of many individuals. This consideration seems to have escaped Mr. Darwin, for at p. 104 of his last (fifth) edition of " Natural Selection," he admits, with great candor, that until reading this arti- 34 Mr. Smith, of the Entomological department of the British Museum, has kindly informed me that the individuals intermediate in structure are very few in number — not more than five per cent. — compared with the number of distinctly differentiated individuals. Besides, in the Brazilian kinds these intermediate forms are wanting. 70 THE GENESIS OF SPECIES. [CHAP. cle he did not " appreciate how rarely single variations, whether slight or strongly marked, could be perpetuated." The North British Review (speaking of the supposition that a species is changed by the survival of a few individu- als in a century through a similar and favorable variation) says : " It is very difficult to see how this can be accom- plished, even when the variation is eminently favorable in- deed ; and still more difficult when the advantage gained is very slight, as must generally be the case. The advantage, whatever it may be, is utterly out-balanced by numerical inferiority. A million creatures are born; ten thousand survive to produce offspring. One of the million has twice as good a chance as any other of surviving ; but the chances are fifty to one against the gifted individuals being one of the hundred survivors. No doubt the chances are twice as great against any one other individual, but this does not prevent their being enormously in favor of some average in- dividual. However slight the advantage may be, if it is shared by half the individuals produced, it will probably be present in at least fifty-one of the survivors, and in a larger proportion of their offspring ; but the chances are against the preservation oi any one ' sport ' (i. e., sudden, marked . variation) in a numerous tribe. The vague use of an im- perfectly-understood doctrine of chance has led Darwinian supporters, first, to confuse the two cases above distin- guished ; and, secondly, to imagine that a very slight bal- ance in favor of some individual sport must lead to its per- petuation. All that can be said is that in the above ex- ample the favored sport would be preserved once in fifty times. Let us consider what will be its influence on the main stock when preserved. It will breed and have a pro- geny of say 100 ; now this progeny will, on the whole, be intermediate between the average individual and the sport. The odds in favor of one of this generation of the new breed will be, say one and a half to one, as compared with the II.] INCIPIENT STRUCTURES. 71 average individual; the odds in their favor will, therefore, be less than that of their parents; but owing to their greater number, the chances are that about one and a half of them would survive. Unless these breed together, a most improbable event, their progeny would again approach the average individual ; there would be 150 of them, and their superiority would be, say in the ratio of one in a quarter to one ; the probability would now be that nearly two of them would survive, and have 200 children, with an eighth superiority. Bather more than two of these would survive; but the superiority would again dwindle, until after a few generations it would no longer be observed, and would count for no more in the struggle for life than any of the hundred trifling advantages which occur in the ordi- nary organs. An illustration will bring this conception home. Suppose a white man to have been wrecked on an island inhabited by negroes, and to have established him- self in friendly relations with a powerful tribe, whose cus- toms he has learned. Suppose him to possess the physical strength, energy, and ability of a dominant white race, and let the food and climate of the island suit his constitution ; grant him every advantage which we can conceive a white to possess over the native ; concede that in the struggle for existence his chance of a long life will be much superior to that of the native chiefs ; yet from all these admissions, there does not follow the conclusion that, after a limited or unlimited number of generations, the inhabitants of the isl- and will be white. Our shipwrecked hero would probably become king ; he would kill a great many blacks in the struggle for existence ; he would have a great many wives and children." ..." In the first generation there will be some dozens of intelligent young mulattoes, much superior in average intelligence to the negroes. We might expect the throne for some generations to be occupied by a more or less yellow king ; but can any one believe that the whole 72 THE GENESIS OF SPECIES. [CHAP. island will gradually acquire a white, or even a yellow, pop- ulation?" " Darwin says that in the struggle for life a grain may turn the balance in favor of a given structure, which will then be preserved. But one of the weights in the scale of Nature is due to the number of a given tribe. Let there be 7,000 A's and 7,000 B's, representing two varieties of a given an- imal, and let all the B's, in virtue of a slight difference of structure, have the better chance of life by -^-^ Part- We must allow that there is a slight probability that the de- scendants of B will supplant the descendants of A; but let there be only 7,001 A's against 7,000 B's at first, and the chances are once more equal, while if there be 7,002 A's to start, the odds would be laid on the A's. True, they stand a greater chance of being killed ; but then they can better afford to be killed. The grain will only turn the scales when these are very nicely balanced, and an advantage in numbers counts for weight, even as an advantage in struct- ure. As the numbers of the favored variety diminish, so must its relative advantages increase, if the chance of its existence is to surpass the chance of its extinction, until hardly any conceivable advantage would enable the de- scendants of a single pair to exterminate the descendants of many thousands if they and their descendants are sup- posed to breed freely with the inferior variety, and so grad- ually lose their ascendency." Mr. Darwin himself says of the article quoted : " The justice of these remarks cannot, I think, be disputed. If, for instance, a bird of some kind could procure its food more easily by having its beak curved, and if one were born with its beak strongly curved, and which consequently flourished, nevertheless there would be a very poor chance of this one individual perpetuating its kind to the exclusion of the com- mon form." This admission seems almost to amount to a change of front in the face of the enemy ! II.] INCIPIENT STRUCTURES. 73 These remarks have been quoted at length because they so greatly intensify the difficulties brought forward in this chapter. If the most favorable variations have to contend with such difficulties, what must be thought as to the chance of preservation of the slightly-displaced eye in a sole or of the incipient development of baleen in a whale ? SUMMARY AND CONCLUSION. It has been here contended that a certain few facts, out of many which might have been brought forward, are incon- sistent with the origination of species by " Natural Selec- tion " only or mainly. Mr. Darwin's theory requires minute, indefinite, fortui- tous variations of all parts in all directions, and he insists that the sole operation of " Natural Selection " upon such is sufficient to account for the great majority of organic forms, with their most complicated structures, intricate mutual adaptations, and delicate adjustments. To this conception has been opposed the difficulties presented by such a structure as the form of the giraffe, which ought not to have been the solitary structure it is ; also the minute beginnings and the last refinements of pro- tective mimicry equally difficult or rather impossible to ac- count for by " Natural Selection." Again, the difficulty as to the heads of flat-fishes has been insisted on, as also the origin, and at the same time the constancy, of the limbs of the highest animals. Reference has also been made to the whalebone of whales, and to the impossibility of under- standing its origin through "Natural Selection" only; the same as regards the infant kangaroo, with its singular defi- ciency of power compensated for by maternal structures on the one hand, to which its own breathing-organs bear direct relation on the other. Again, the delicate and complex pedicellariae of Echinoderms, with a certain process of devel- opment (through a secondary larva) found in that class, 4 74 THE GENESIS OF SPECIES. [CHAP. together with certain other exceptional modes of develop- ment, have been brought forward. The development of color in certain apes, the hood of the cobra, and the rattle of the rattlesnake, have also been cited. Again, difficulties as to the process of formation of the eye and ear, and as to the fully-developed condition of those complex organs, as well as of the voice, have been considered. The beauty of certain shell-fish ; the wonderful adaptations of structure, and variety of form and resemblance, found in orchids ; together with the complex habits and social conditions of certain ants, have been hastily passed in review. When all these complications are duly weighed and considered, and when it is borne in mind how necessary it is for the permanence of a new variety that many individuals in each case should be simultaneously modified, the cumulative argument seema irresistible. The author of this book can say that, though by no means disposed originally to dissent from the theory of " Natural Selection," if only its difficulties could be solved, he has found each successive year that deeper consideration and more careful examination have more and more brought home to him the inadequacy of Mr. Darwin's theory to ac- count for the preservation and intensification of incipient, specific, and generic characters. That minute, fortuitous, and indefinite variations could have brought about such spe- cial forms and modifications as have been enumerated in this chapter, seems to contradict not imagination, but reason. That either many individuals among a species of butter- fly should be simultaneously preserved through a similar accidental and minute variation in one definite direction, when variations in many other directions would also pre- serve ; or that one or two so varying should succeed in sup- planting the progeny of thousands of other individuals, and that this should by no other cause be carried so far as to produce the appearance (as we have before stated) of spots II.] INCIPIENT STRUCTURES. 75 of fungi, etc. — are alternatives of an improbability so ex- treme as to be practically equal to impossibility. In spite of all the resources of a fertile imagination, the Darwinian, pure and simple, is reduced to the assertion of a paradox as great as any he opposes. In the place of a mere assertion of our ignorance as to the way these phe- nomena have been produced, he brings forward, as their explanation, a cause which it is contended in this work is demonstrably insufficient. Of course in this matter, as elsewhere throughout Nature, we have to do with the operation of fixed and constant natural laws, and the knowledge of these may before long be obtained by human patience or human genius ; but there is, it is believed, already enough evidence to show that these as yet unknown natural laws or law will never be resolved into the action of " Natural Selection," but will constitute or exemplify a mode and condition of organic action of which the Darwinian theory takes no account whatsoever. 76 THE GENESIS OF SPECIES. [CHAP. CHAPTER III. THE COEXISTENCE OF CLOSELY-SIMILAR STRUCTURES OP DIVERSE ORIGIN. Chances against Concordant Variations.— Examples of Discordant Ones.— Concordant Variations not unlikely on a non-Darwinian Evolutionary Hypothesis. — Placental and Implacental Mammals. — Birds and Reptiles. — Independent Origins of Similar Sense Organs.— The Ear— The Eye.— Other Coincidences.— Causes besides Natural Selection produce Concordant Variations in Certain Geographical Regions. — Causes besides Natural Selection produce Concordant Variations in Certain Zoological and Botanical Groups.— There are Homologous Parts not genetically related. — Harmony in respect of the Organic and Inorganic Worlds. — Summary and Conclusion. THE theory of " Natural Selection " supposes that the varied forms and structure of animals and plants have been built up merely by indefinite, fortuitous,1 minute variations in every part and in all directions — those variations only being preserved which are directly or indirectly useful to the individual possessing them, or necessarily correlated with such useful variations. On this theory the chances are almost infinitely great against the independent, accidental occurrence and pres- ervation of two similar series of minute variations result- ing in the independent development of two closely-similar forms. In all cases, no doubt (on this same theory), some adaptation to habit or need would gradually be evolved, but that adaptation would surely be arrived at by different roads. The organic world supplies us with multitudes of 1 By accidental variations Mr. Darwin does not, of course, mean to imply variations really due to " chance," but to utterly indeterminate antecedents. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 77 examples of similar functional results being attained by the most diverse means. Thus the body is sustained in the air by birds and by bats. In the first case it is so sustained by a limb in which the bones of the hand are excessively reduced, but which is provided with immense outgrowths from the skin — namely, the feathers of the wing. In the second case, however, the body is sustained in the air by a limb in which the bones of the hand are enormously in- WENG-BONES OF PTERODACTYL, BAT, AND BIRD. (Copied, by permission, from Mr. Andrew Murray's " Geographical Distribution of Mammals.'1'') creased in length, and so sustain a great expanse of naked skin, which is the flying membrane of the bat's wing. Cer- tain fishes and certain reptiles can also flit and take very prolonged jumps in the air. The flying-fish, however, takes these by means of a great elongation of the rays of the pectoral fins — parts which cannot be said to be of the same nature as the constituents of the wing of either the bat or the bird. The little lizard, which enjoys the formi- dable name of " flying-dragon," flits by means of a structure altogether peculiar — namely, by the liberation and great elongation of some of the ribs which support a fold of skin. In the extinct pterodactyls — which were truly flying rep- 78 THE GENESIS OF SPECIES. [CHAP. tiles — we meet with an approximation to the structure of the bat, but in the pterodactyl we have only one finger elongated in each hand : a striking example of how the very same function may be provided for by a modification similar in principle, yet surely manifesting the indepen- dence of its origin. When we go to lower animals, we find flight produced by organs, as the wings of insects, which are not even modified limbs at all ; or we find even the SKELETON OF THE FLYING-DRAGON. (Showing the elongated ribs which support the flitting organ.) function sometimes subserved by quite artificial means, as in the aerial spiders, which use their own threads to float with in the air. In the vegetable kingdom the atmosphere is often made use of for the scattering of seeds, by their being furnished with special structures of very different kinds. The diverse modes by which such seeds are dis- persed are well expressed by Mr. Darwin. He says : 2 52 " Origin of Species," 6th edit., p. 235. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 79 " Seeds are disseminated by their minuteness — by their capsule being converted into a light balloon-like envelope — by being embedded in pulp or flesh, formed of the most diverse parts, and rendered nutritious, as well as conspicu- ously colored, so as to attract and be devoured by birds — by having hooks and grapnels of many kinds and serrated awns, so as to adhere to the fur of quadrupeds — and by be- ing furnished with wings and plumes, as different in shape as elegant in structure, so as to be wafted by every breeze." Again, if we consider the poisoning apparatus pos- sessed by different animals, we find in serpents a perfo- rated— or, rather, very deeply-channelled — tooth. In wasps and bees the sting is formed of modified parts, accessory in reproduction. In the scorpion, we have the median ter- minal process of the body specially organized. In the spider, we have a specially-constructed antenna ; and final- ly in the centipede a pair of modified thoracic limbs. A CENTIPEDE. It would be easy to produce a multitude of such in- stances of similar ends being attained by dissimilar means, and it is here contended that by " the action of Natural 80 THE GENESIS OF SPECIES. [CHAP. Selection " only it is so improbable as to be practically im- possible for two exactly-similar structures to have ever been independently developed. It is so because the num- ber of possible variations is indefinitely great, and it is therefore an indefinitely great number to one against a similar series of variations occurring and being similarly preserved in any two independent instances. The difficulty here asserted applies, however, only to pure Darwinism, which makes use only of indirect modifi- cations through the survival of the fittest. Other theories (for example, that of Mr. Herbert Spen- cer) admit the direct action of conditions upon animals and plants — in ways not yet fully understood — there being con- ceived to be at the same time a certain peculiar but limited power of response and adaptation in each animal and plant so acted on. Such theories have not to contend against the difficulty proposed, and it is here urged that even very complex extremely similar structures have again and again been developed quite independently one of the other, and this because the process has taken place not by merely haphazard, indefinite variations in all directions, but by the concurrence of some other and internal natural law or laws cooperating with external influences and with "Natural Selection " in the evolution of organic forms. It must never be forgotten that to admit any such con- stant operation of any such unknown natural cause is to deny the purely Darwinian theory, which relies upon the survival of the fittest by means of minute fortuitous indefi- nite variations. Among many other obligations which the author has to acknowledge to Prof. Huxley are, the pointing out of this very difficulty, and the calling his attention to the striking resemblance between certain teeth of the dog and of the thylacine as one instance, and certain ornithic pe- culiarities of pterodactyls as another. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 81 Mammals3 are divisible into one great group, which comprises the immense majority of kinds termed, from their mode of reproduction, placental Mammals, and into another very much smaller group comprising the pouched- beasts or marsupials (which are the kangaroos, bandicoots, phalangers, etc., of Australia), and the true opossums of America, called implacental Mammals. Now, the placen- tal mammals are subdivided into various orders, among which are the flesh-eaters (Garni vora, i. e., cats, dogs, ot- ters, weasels, etc.), and the insect-eaters (Insectivora, i. e., moles, hedgehogs, shrew-mice, etc.). The marsupial mam- mals also present a variety of forms (some of which are carnivorous beasts, while others are insectivorous), so marked that it has been even proposed to divide them into orders parallel to the orders of placental beasts. The resemblance, indeed, is so striking as, on Darwinian principles, to suggest the probability of genetic affinity ; and it even led Prof. Huxley, in his Hunterian Lectures, in 1866, to promulgate the notion that a vast and widely-dif- fused marsupial fauna may have existed anteriorly to the TEETH OF TJROTBICHTTS AND PEBAMELE8 development of the ordinary placental, non-pouched beasts, and that the carnivorous, insectivorous, and herbivorous 3 1. e., warm-blooded animals which suckle their young, such as apes, bats, hoofed beasts, lions, dogs, bears, weasels, rats, squirrels, armadillos, sloths, whales, porpoises, kangaroos, opossums, etc. 82 THE GENESIS OF SPECIES. [CHAP. placentals may have respectively descended from the car- nivorous, insectivorous, and herbivorous marsupials. Among other points Prof. Huxley called attention to the resemblance between the anterior molars of the placen- tal dog with those of the marsupial thylacine. These, in- deed, are strikingly similar, but there are better examples still of this sort of coincidence. Thus it has often been re- marked that the insectivorous marsupials, e. g., ferameles, wonderfully correspond, as to the form of certain of the grinding teeth, with certain insectivorous placentals, e. g., Urotrichus. Again, the saltatory insectivores of Africa (Macrosce- lides) not only resemble the kangaroo family (Macropodidce) in their jumping habits and long hind-legs, but also in the structure of their molar teeth, and even further, as I have elsewhere * pointed out, in a certain similarity of the upper ,cutting teeth, or incisors. Now, these correspondences are the more striking when we bear in mind that a similar dentition is often put to very different uses. The food of different kinds of apes is very different, yet how uniform is their dental structure ! Again, who, looking at the teeth of different kinds of bears, would ever suspect that one kind was frugivorous, and another a devourer exclusively of animal food ? The suggestion made by Prof. Huxley was therefore one which had much to recommend it to Darwinians, though it has not met with any notable acceptance, and though he seems himself to have returned to the older no- tion, namely, that the pouched-beasts, or marsupials, are a special ancient offshoot from the great mammalian class. But, whichever view may be the correct one, we have in either case a number of forms similarly modified in har- mony with surrounding conditions, and eloquently proclaim- ing some natural plastic power, other than mere fortuitous 4 " Journal of Anatomy and Physiology " (1868), voL ii., p. 139. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 83 variation with survival of the fittest. If, however, the reader thinks that teeth are parts peculiarly qualified for rapid variation (in which view the author cannot concur), he is 'requested to suspend his judgment till he has con- sidered the question of the independent evolution of the highest organs of sense. If this seems to establish the existence of some other law than that of " Natural Selec- tion," then the operation of that other law may surely be also traced in the harmonious coordinations of dental form. The other difficulty, kindly suggested to me by the learned professor, refers to the structure of birds, and of extinct reptiles more or less related to them. The class of birds is one which is remarkably uniform in its organization. So much is this the case, that the best mode of subdividing the class is a problem of the greatest difficulty. Existing birds, however, present forms which, though closely resembling in the greater part of their struct- ure, yet differ importantly the one from the other. One form is exemplified by the ostrich, rhea, emeu, cassowary, apteryx, dinornis, etc. These are the struthious birds. All other existing birds belong to the second division, and are called (from the keel on the breast-bone) carinate birds. Now, birds and reptiles have such and so many points in common that Darwinians must regard the former as modified descendants of ancient reptilian forms. But on Darwinian principles it is impossible that the class of birds so uniform and homogeneous should have had a double rep- tilian origin. If one set of birds sprang from one set of rep- tiles, and another set of birds from another set of reptiles, the two sets could never, by " Natural Selection " only, have grown into such a perfect similarity. To admit such a phenomenon would be equivalent to abandoning the theory of " Natural Selection " as the sole origin of species. Now, until recently it has generally been supposed by 84: THE GENESIS OF SPECIES. [CHAP. evolutionists that those ancient flying reptiles, the ptero- dactyls, or forms allied to them, were the progenitors of the class of birds ; and certain parts of their structure espe- cially support this view. Allusion is here made to the blade-bone (scapula) and the bone which passes down from the shoulder-joint to the breast-bone (viz., the coracoid). These bones are such remarkable anticipations of the same parts in ordinary (i. e., carinate) birds that it is hardly pos- sible for a Darwinian not to regard the resemblance as due to community of origin. This resemblance was carefully pointed out by Prof. Huxley in his " Hunterian Course " for 1867, when attention was called to the existence in Di- morphodon macronyx of even that small process which in birds gives attachment to the upper end of the merry- thought. Also Mr. Seeley B has shown that in pterodac- tyls, as in birds, the optic lobes of the brain were placed low down on each side — " lateral and depressed." Never- theless, the view has been put forward and ably maintained by the same professor,6 as also by Prof. Cope in the United States, that the line of descent from reptiles to birds hajs not been from ordinary reptiles, through pterodactyl-like forms, to ordinary birds, but to the struthious ones from certain extinct reptiles termed Dinosauria ; one of the most familiarly known of which is the Iguanodon of the Weal- den formation. In these Dinosauria we find skeletal char- acters unlike those of ordinary (i. e., carinate) birds, but closely resembling in certain points the osseous structure of the struthious birds. Thus a difficulty presents itself as to the explanation of the three following relationships : (1) That of the Pterodactyls with carinate birds ; (2) that 5 See "Ann. and Mag. of Nat. Hist." for August, 1870, p. 140. 6 See " Proceedings of the Koyal Institution," vol. v., part iv,, p. 278 : Report of a Lecture delivered February 7, 1868. Also " Quarterly Jour- nal of the Geological Society," February, 1870. "Contributions to the Anatomy and Taxonomy of the Dinosauria." III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 85 of the Dinosauria with struthious birds; (3) that of the carinate and struthious birds with each other. Either birds must have had two distinct origins whence they grew to their present conformity, or the very same skeletal, and probably cerebral characters, must have spon- taneously and independently arisen. Here is a dilemma, either horn of which bears a threatening aspect to the exclusive supporter of " Natural Selection," and between which it seems somewhat difficult to choose. It has been suggested to me that this difficulty may be evaded by considering pterodactyls and carinate birds as independent branches from one side of an ancient common trunk, while similarly the Dinosauria and struthious birds are taken to be independent branches from the other side of the same common trunk ; the two kinds of birds resem- bling each other so much on account of their later develop- ment from that trunk as compared with the development of the reptilian forms. But to this it may be replied that the ancient common stock could not have had at one and the same time a shoulder structure of both kinds. It must have been that of the struthious birds or that of the cari- nate birds, or something different from both. If it was that of the. struthious birds, how did the pterodactyls and cari- nate birds independently arrive at the very same divergent structure ? If it was that of the carinate birds, how did the struthious birds and Dinosauria independently agree to differ ? Finally, if it was something different from either, how did the carinate birds and pterodactyls take on inde- pendently one special common structure when disagreeing in so many ; while the struthious birds, agreeing in many points with the Dinosauria, agree yet more with the cari- nate birds ? Indeed, by no arrangement of branches from a stem can the difficulty be evaded. Prof. Huxley seems inclined 7 to cut the Gordian knot 7 "Proceedings of Geological Society," November,. 1869, p. 38. 86 THE GENESIS OF SPECIES. [CHAP. by considering the shoulder structure of the pterodactyl as independently educed, and having relation to physiology only. This conception is one which harmonizes completely with the views here advocated, and with those of Mr. Her- bert Spencer, who also calls in direct modification to the aid of " Natural Selection." That merely minute, indefinite variations in all directions should unaided have indepen- dently built up the shoulder structure of the pterodactyls and carinate birds, and have laterally depressed their optic lobes, at a time so far back as the deposition of the Oolite THE ARCHEOPTEBYX (of the Oolite strata). strata,8 is a coincidence of the highest improbability ; but that an innate power and evolutionary law, aided by the corrective action of " Natural Selection," should have fur- nished like needs with like aids, is not at all improbable. The difficulty does not tell against the theory of evolution, but only against the specially Darwinian form of it. Now, this form has never been expressly adopted by Prof. Huxley ; 8 The archeopteryx of the oolite has the true carinate shoulder struct- III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 87 so far from it, in his lecture on this subject at the Royal Institution before referred to, he observes : 9 " I can testify, from personal experience, it is possible to have a complete faith in the general doctrine of evolution, and yet to hesi- tate in accepting the Nebular, or the Uniformitarian, or the Darwinian hypotheses in all their integrity and ful- ness." It is quite consistent, then, in the professor to explain the difficulty as he does ; but it would not be similarly so with an absolute and pure Darwinian. Yet stronger arguments of an analogous kind are, how- ever, to be derived from the highest organs of sense. In the most perfectly-organized animals — those, namely, which, like ourselves, possess a spinal column — the internal organs of hearing consist of two more or less complex membranous sacs (containing calcareous particles — otoliths), which are primitively or permanently lodged in two chambers, one on each side of the cartilaginous skull. The primitive cartila- ginous cranium supports and protects the base of the brain, and the auditory nerves pass from the brain into the cartila- ginous chambers to reach the auditory sacs. These com- plex arrangements of parts could not have been evolved by "Natural Selection," i. e., by minute accidental variations, except by the action of such through a vast period of time ; nevertheless, it was fully evolved at the time of the deposi- tion of the upper Silurian rocks. Cuttle-fishes ( Cephalopoda) are animals belonging to the molluscous primary division of the animal kingdom, which division contains animals formed upon a type of structure utterly remote from that on which the animals of the higher division provided with a spinal column are construct- ed. And indeed no transitional form (tending even to bridge over the chasm between these two groups) has ever 9 " Proceedings of the Royal Institution," vol. v., p. 279. THE GENESIS OF SPECIES. [CHAP. yet been discovered, either living or in a fossilized condi- tion.10 Nevertheless, in the two-gilled Cephalopods (Dibran- chiata) we find the brain supported and protected by a car- tilaginous cranium. In the base of this cranium are two cartilaginous chambers. In each chamber is a membranous sac containing an otolith, and the auditory nerves pass from CUTTLE-FISH. A. Ventral aspect. B. Dorsal aspect. the cerebral ganglia into the cartilaginous chambers to reach the auditory sacs. Moreover, it has been suggested by Prof. Owen that sinuosities between processes projecting from the inner wall of each chamber " seem to be the first rudiments of those which, in the higher classes (i. e., in animals with a spinal column), are extended in the form of 10 This remark is made without prejudice to possible affinities in the direction of the Ascidians — an affinity which, if real, would be irrelevant to the question here discussed. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 89 canals and spiral chambers, within the substance of the dense nidus of the labyrinth." 3 Here, then, we have a wonderful coincidence indeed ; two highly-complex auditory organs, marvellously similar in structure, but which must nevertheless have been devel- oped in entire and complete independence one of the other ! It would be difficult to calculate the odds against the independent occurrence and conservation of two such complex series of merely accidental and minute haphazard variations. And it can never be maintained that the sense of hearing could not be efficiently subserved otherwise than by such sacs, in cranial cartilaginous capsules so situ- ated in relation to the brain, etc. Our wonder, moreover, may be increased when we recollect that the two-gilled cephalopods have not yet been found below the lias, where they at once abound ; whereas the four-gilled cephalopods are Silurian forms. Moreover, the absence is in this case significant in spite of the imper- fection of the geological record, because when we consider how many individuals of various kinds of four-gilled cephal- opods have been found, it is fair to infer that at the least a certain small percentage of dibranchs would also have left traces of their presence had they existed. Thus it is probable that some four-gilled form was the progenitor of the dibranch cephalopods. Now, the four-gilled kinds (judging from the only existing form, the nautilus) had the auditory organ in a very inferior condition of development to what we find in the dibranch ; thus we have not only evidence of the independent high development of the organ in the former, but also evidence pointing toward a certain degree of comparative rapidity in its development. Such being the case with regard to the organ of hear- ing, we have another yet stronger argument with regard to 11 " Lectures on the Comp. Anat. of the Invertebrate Animals," 2d edit., 1855, p. 619 ; and Todd's " Cyclopaedia of Anatomy," vol. i., p. 554. 90 THE GENESIS OF SPECIES. [CHAP. the organ of sight, as has been well pointed out by Mr. J. J. Murphy.12 He calls attention to the fact that the eye must have been perfected in at least " three distinct lines of descent," alluding not only to the molluscous division of the animal kingdom, and the division provided with a spinal column, but also to a third primary division, namely, that which includes all insects, spiders, crabs, etc., which are spoken of as Annulosa, and the type of whose structure is as distinct from that of the molluscous type on the one hand, as it is from that of the type with a spinal column (i. e., the vertebrate type) on the other. In the cuttle-fishes we find an eye even more complete- ly constructed on the vertebrate type than is the ear. Sclerotic, retina, choroid, vitreous humor, lens, aqueous hu- mor, all are present. The correspondence is wonderfully complete, and there can hardly be any hesitation in saying that for such an exact, prolonged, and correlated series of similar structures to have been brought about in two inde- pendent instances by merely indefinite and minute acci- dental variations, is an improbability which amounts prac- tically to impossibility. Moreover, we have here again the same imperfection of the four-gilled cephalopod, as com- pared with the two-gilled, and therefore (if the latter pro- ceeded from the former) a similar indication of a certain comparative rapidity of development. Finally, and this is perhaps one of the most curious circumstances, the process of formation appears to have been, at least in some re- spects, the same in the eyes of these molluscous animals as in the eyes of vertebrates. For in these latter the cornea is at first perforated, while different degrees of perforation of the same part are presented by different adult cuttle- fishes— large in the calamaries, smaller in the octopods, and reduced to a minute foramen in the true cuttle-fish sepia. 12 See " Habit and Intelligence," voL i, p. 321. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 91 Some may be disposed to object that the conditions requisite for effecting vision are so rigid that similar results in all cases must be independently arrived at. But to this objection it may well be replied that Nature herself has demonstrated that there is no such necessity as to the de- tails of the process. For in the higher Annulosa, such as the dragon-fly, we meet with an eye of an unquestionably very high degree of efficiency, but formed on a type of structure only remotely comparable with that of the fish or the cephalopod. The last-named animal might have had an eye as efficient as that of a vertebrate, but formed on a distinct type, instead of being another edition, as it were, of the very same structure. In the beginning of this chapter examples have been given of the very diverse mode in which similar results have in many instances been arrived at; on the other hand, we have in the fish and the cephalopod not only the eye, but at one and the same time the ear also similarly evolved, yet with complete independence. Thus it is here contended that the similar and complex structures of both the highest organs of sense, as developed in the vertebrates on the one hand, and in the mollusks on the other, present us with residuary phenomena for which " Natural Selection " alone is quite incompetent to account ; and that these same phenomena must therefore be consid- ered as conclusive evidence for the action of some other natural law or laws conditioning the simultaneous and in- dependent evolution of these harmonious and concordant adaptations. Provided with this evidence, it may be now profitable to enumerate other correspondences, which are not perhaps in themselves inexplicable by Natural Selection, but which are more readily to be explained by the action of the un- known law or laws referred to — which action, as its neces- sity has been demonstrated in one case, becomes a priori probable in the others. 92 THE GENESIS OF SPECIES. [CHAP. Thus the great oceanic Mammalia — the whales — show striking resemblances to those prodigious, extinct, marine SKELETON OF AN ICHTHYOSAUBUS. reptiles, the Ichthyosauria, and this not only in structures readily referable to similarity of habit, but in such matters as greatly elongated premaxillary bones, together with the concealment of certain bones of the skull by other cranial bones. Again, the aerial mammals, the bats, resemble those fly- ing reptiles of the secondary epoch, the pterodactyls; not only to a certain extent in the breast-bone and mode of sup- porting the flying membrane, but also in the proportions of different parts of the spinal column and the hinder (pelvic) limbs Also bivalve shell-fish (i. e., creatures of the muscle, cockle, and oyster class, which receive their name from the body being protected by a double shell, one valve of which is placed on each side) have their two shells united by one or two powerful muscles, which pass directly across from one shell to the other, and which are termed " adductor muscles " because by their contraction they bring together the valves and so close the shell. Now there are certain animals which belong to the crab and lobster class (Crustacea) — a class constructed on an utterly different type from that on which the bivalve shell- fish are constructed — which present a very curious approxi- mation to both the form and, in a certain respect, the structure of true bivalves. Allusion is here made to certain III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 93 small Crustacea — certain phyllopods and ostracods — which have the hard outer coat of their thorax so modified as to look wonderfully like a bivalve shell, although its nature and composition are quite different. But this is by no means all — not only is there this external resemblance CTTHEEIDEA TOROSA. [An ostracod (Crustacean), externally like a bivalve shell-fish (Lamellibranch).] between the thoracic armor of the crustacean and the bivalve shell, but the two sides of the ostracod and phyllo- pod thorax are connected together also by an adductor muscle ! The pedicellariae of the echinus have been already spo- ken of, and the difficulty as to, their origin from minute, fortuitous, indefinite variations has been stated. But structures essentially similar (called avicularia, or " bird's- head processes") are developed from the surface of the compound masses of certain of the highest of the polyp- like animals (viz., the Polyzoa or, as they are sometimes called, the Bryozoa). These compound animals have scattered over the surface of their bodies minute processes, each of which is like the 94 THE GENESIS OF SPECIES. [CHAP. head of a bird, with an upper and lower beak, the whole supported on a slender neck. The beak opens and shuts at intervals, like the jaws of the pedicellariae of the echi- nus, and there is altogether, in general principle, a remark. POLYZOON WITH BIRD'S-HEAD PEOCE88E8. able similarity between the structures. Yet the echinus can have, at the best, none but the most distant genetic relationship with the Polyzoa. We have here again, III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 95 therefore, complex and similar organs of diverse and inde- pendent origin. BIRD'S-HEAD PROCESSES VERY GREATLY ENLARGED. In the highest class of animals (the Mammalia) we have almost always a placental mode of reproduction, i. e., the blood of the foetus is placed in nutritive relation with the blood of the mother by means of vascular prominences. No trace of such a structure exists in any bird or in any reptile, and yet it crops out again in certain sharks. There indeed it might well be supposed to end, but, marvellous as it seems, it reappears in very lowly creatures ; namely, in certain of the ascidians, sometimes called tunicaries or sea-squirts. Now, if we were to concede that the ascidians were the common ancestors 1S of both these sharks and of the higher mammals, we should be little, if any, nearer to an explana- tion of the phenomenon by means of " Natural Selection," for in the sharks in question the vascular prominences are developed from one fcetal structure (the umbilical vesicle), while in the the higher mammals they are developed from quite another part, viz., the allantois. So great, however, is the number of similar, but ap- parently independent structures, that we suffer from a per- fect embarras de richesses. Thus, for example, we have the convoluted windpipe of the sloth, reminding us of the condition of the windpipe in birds ; and in another mammal, 13 A view recently propounded by Kowalewsky. 96 THE GENESIS OF SPECIES. [CHAP. allied to the sloth, namely, the great ant-eater (Myrme- cophaga), we have again an ornithic character in its horny gizzard-like stomach. In man and the highest apes the caecum has a vermiform appendix, as it has also in the wombat ! Upper Figure — ANTECHTNUS MINTJTISSIMTTS (implacentaT). Lower Figure— Mus DELICATUXUS (plae&ntaf). Also the similar forms presented by the crowns of the teeth in some seals, in certain sharks, and in some extinct Cetacea, may be referred to ; as also the similarity of the beak in birds, some reptiles, in the tadpole, and cuttle- fishes. As to entire external form, may be adduced the wonderful similarity between a true mouse (Mus delicatu- lus) and a small marsupial, pointed out by Mr. Andrew III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 97 Murray in his work on the " Geographical Distributions of Mammals," p. 53, and represented in the frontispiece by figures copied from Gould's " Mammals of Australia ; " but instances enough for the present purpose have been already quoted. Additional reasons for believing that similarity of struct- ure is produced by other causes than merely by " Natural Selection" are furnished by certain facts of zoological geography, and by a similarity in the mode of variation being sometimes extended to several species of a genus, or even to widely-different groups ; while the restriction and the limitation of such similarity are often not less remarkable. Thus Mr. Wallace says,14 as to local influence : " Larger or smaller districts, or even single islands, give a special character to the majority of their Papilionidae. For in- stance: 1. The species of the Indian region (Sumatra, Java, and Borneo) are almost invariably smaller than the allied species inhabiting Celebes and the Moluccas. 2. The species of New Guinea and Australia are also, though in a less degree, smaller than the nearest species or varieties of the Moluccas. 3. In the Moluccas themselves the species of Amboyna are the largest. 4. The species of Celebes equal or even surpass in size those of Amboyna. 5. The species and varieties of Celebes possess a striking charac- ter in the form of the anterior wings, different from that of the allied species and varieties of all the surrounding islands. 6. Tailed species in India or the Indian region be- come tailless as they spread eastward through the Archi- pelago. 7. In Amboyna and Ceram the females of several species are dull-colored, while in the adjacent islands they are more brilliant." Again : 1B " In Amboyna and Ceram the female of the large and handsome Ornithoptera Helena has a large patch on the hind- wings constantly of a pale dull ochre or buff color ; while in the scarcely distinguish- 14 "Natural Selection," p. 167. 15 Ibid., p. 173. 98 THE GENESIS OF SPECIES. [€HAP. able varieties from the adjacent islands, of Bouru and New Guinea, it is of a golden yellow, hardly inferior in brilliancy to its color in the male sex. The female of Ornithoptera Priamus (inhabiting Amboyna and Ceram exclusively) is of a pale dusky-brown tint, while in all the allied species the same sex is nearly black, with contracted white mark- ings. As a third example, the female of Papilio Ulysses has the blue color obscured by dull and dusky tints, while in the closely-allied species from the surrounding islands, the faemles are of almost as brilliant an azure blue as the males. A parallel case to this is the occurrence, in the small islands of Goram, Matabello, Ke, and Aru, of several distinct species of Euploea and Diadema, having broad bands or patches of white, which do not exist in any of the allied species from the larger islands. These facts seem to indicate some local influence in modifying color, as unintelligible and almost as remarkable as that which has resulted in the modifications of form previously de- scribed." After endeavoring to explain some of the facts in a way to be noticed directly, Mr. Wallace adds : 16 " But even the conjectural explanation now given fails us in the other cases of local modification. Why the species of the Western Islands should be smaller than those farther east; why those of Amboyna should exceed in size those of Gilolo and New Guinea ; why the tailed species of India should begin to lose that appendage in the islands, and retain no trace of it on the borders of the Pacific ; and why, in three separate cases, the females of Amboyna species should be less gayly attired than the corresponding females of the sur- rounding islands, are questions which we cannot at present attempt to answer. That they depend, however, on some general principle is certain, because analogous facts have been observed in other parts of the world. Mr. Bates in- 16 "Natural Selection," p. 177. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 99 forms me that, in three distinct groups, Papilios, which, on the Upper Amazon, and in most other parts of South America, have spotless upper wings, obtain pale or white spots at Para and on the Lower Amazon, and also that the ^Eneas group of Papilios never have tails in the equatorial regions and the Amazon valley, but gradually acquire tails in many cases as they range toward the northern or southern tropic. Even in Europe we have somewhat similar facts, for the species and varieties of butterflies peculiar to the Island of Sardinia are generally smaller and more deeply colored than those of the main-land, and the same has been recently shown to be the case with the common tortoise- shell butterfly in the Isle of Man ; while Papilio Hospiton, peculiar to the former island, has lost the tail, which is a prominent feature of the closely-allied P. Machaon. " Facts of a similar nature to those now brought for- ward would no doubt be found to occur in other groups of insects, were local faunas carefully studied in relation to those of the surrounding countries ; and they seem to indi- cate that climate and other physical causes have, in some cases, a very powerful effect in modifying specific form and color, and thus directly aid in producing the endless variety of nature." With regard to butterflies of Celebes belonging to dif- ferent families, they present " a peculiarity of outline which distinguishes them at a glance from those of any other part of the world : " IT it is that the upper wings are generally more elongated and the anterior margin more curved. Moreover, there is, in most instances, near the base, an abrupt bend or elbow, which in some species is very con- spicuous. Mr. Wallace endeavors to explain this phenome- non by the supposed presence at some time of special per- secutors of the modified forms, supporting the opinion by the remark that small, obscure, very rapidly flying and mim- 17 " Malay Archipelago," vol. i., p. 439. 100 THE GENESIS OF SPECIES. [CHAP. icked kinds have not had the wing modified. Such an ene- my occasioning increased powers of flight, or rapidity in OUTLINES OP WINGS OF BUTTERFLIES OF CELEBES COMPARED WITH THOSE OF ALLIED SPECIES ELSEWHERE. Outer outline, PapiUo gigon, of Celebes. Inner outline, P. demoUon, of Singapore and Java.— 2. Outer outline, P. miletw, of Celebes. Inner outline, P. sarpedon India.— 3. Outer outline, Tachyris sarinda, Celebes. Inner outline, T. nero. turning, he adds, " one would naturally suppose to be an insectivorous bird ; but it is a remarkable fact that most of the genera of fly-catchers of Borneo and Java on the one III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 101 side, and of the Moluccas on the other, are almost entirely absent from Celebes. Their place seems to be supplied by the caterpillar-catchers, of which six or seven species are known from Celebes, and are very numerous in individuals. We have no positive evidence that these birds pursue but- terflies on the wing, but it is highly probable that they do so when other food is scarce. Mr. Bates suggested to me that the larger dragon-flies prey upon butterflies, but I did not notice that they were more abundant in Celebes than elsewhere." 18 Now, every opinion or conjecture of Mr. Wallace is worthy of respectful and attentive -consideration, but the explanation suggested and before referred to hardly seems a satisfactory one. What the past fauna of Celebes may have been is as yet conjectural. Mr. Wallace tells us that now there is a remarkable scarcity of fly-catchers, and that their place is supplied by birds of which it can only be said that it is " highly probable " that they chase butterflies " when other food is scarce." The quick eye of Mr. Wal- lace failed to detect them in the act, as also to note any unusual abundance of other insectivorous forms, which therefore, considering Mr. Wallace's zeal and powers of ohservation, we may conclude do not exist. Moreover, even if there ever has been an abundance of such, it is by no means certain that they would have succeeded in pro- ducing the conformation in question, for the effect of this peculiar curvature on flight is by no means clear. We have here, then, a structure hypothetically explained by an un- certain property induced by a cause the presence of which is only conjectural. Surely it is not unreasonable to class this instance with the others before given, in which a common modification of form or color coexists with a certain geographical distribu- tion quite independently of the destructive agencies of ani- 18 " Natural Selection," p. 177. 102 THE GENESIS OF SPECIES. [CHAP. mals. If physical causes connected with locality can abbre- viate or annihilate the tails of certain butterflies, why may not similar causes produce an elbow-like prominence on the wings of other butterflies ? There are many such instances of simultaneous modification. Mr. Darwin himself19 quotes Mr. Gould as believing that birds of the same species are more brightly colored under a clear atmosphere, than when living on islands or near the coast. Mr. Darwin also in- forms us that Wollaston is convinced that residence near the sea affects the color of insects ; and finally, that Moquin- Tandon gives a list of plants which, when growing near the sea-shore, have their leaves in some degree fleshy, though not so elsewhere. In his work on u Animals and Plants under Domestication," 20 Mr. Darwin refers to M. Costa as having (in Bull, de la Soc. Imp. d'Acdimat., tome viii., p. 351) stated that "young shells taken from the shores of England and placed in the Mediterranean at once altered their manner of growth, and formed prominent diverging rays like those on the shells of the proper Mediterranean oyster • " also to Mr. Meehan, as stating (Proc. Acad. Nat. JSc. of Philadelphia, Jan. 28, 1862) that " twenty-nine kinds of American trees all differ from their nearest European allies in a similar manner, leaves less toothed, buds and seeds smaller, fewer branchlets," etc. These are striking examples indeed ! But cases of simultaneous and similar modifications abound on all sides. Even as regards our own species there is a very generally admitted opinion that a new type has been developed in the United States, and this in about a couple of centuries only, and in a vast multitude of in- dividuals of diverse ancestry. The instances here given, however, must suffice, though more could easily be added. It may be well now to turn to groups presenting similar variations, not through, but independently of, geographical 19 « Origin of Species," 5th edit., p. 166. 20 Vol. ii., p. 280. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 1Q3 distribution, and, as far as we know, independently of con- ditions other than some peculiar nature and tendency (as yet unexplained) common to members of such groups, which nature and tendency seem to induce them to vary in certain definite lines or directions which are different in THE GEEAT SHIELDED GRASSHOPPER. different groups. Thus with regard to the group of in- sects, of which the walking leaf is a member, Mr. Wallace observes : 21 " The whole family 22 of the Phasmidae, or spectres, to which this insect belongs, is more or less imi- tative, and a great number of the species are called ' walk- ing-stick insects,' from their singular resemblance to twigs and branches." Again, Mr. Wallace 23 tells us of no less than four kinds 21 See " Natural Selection," p. 64. 22 The Italics are not Mr. Wallace's. 23 "Malay Archipelago," vol. ii., p. 150; and "Natural Selection," p. 104. 104 THE GENESIS OF SPECIES. [CHAP. of orioles, which birds mimic, more or less, four species of a genus of honey-suckers, the weak orioles finding their profit in being mistaken by certain birds of prey for the strong, active, and gregarious honey-suckers. Now, many other birds would be benefited by similar mimicry, which is none the less confined, in this part of the world, to the oriole genus. It is true that the absence of mimicry in other forms may be explained by their possessing some other (as TIIE SIX-SHAFTED BIKD OF PARADISE. yet unobserved) means of preservation. But it is neverthe- less remarkable, not so much that one species should mimic, as that no less than four should do so in different ways and degrees, all these four belonging to one and the same genus. In other cases, however, there is not even the help of protective action to account for the phenomenon. Thus we have the wonderful birds of Paradise,24 which agree in de- 84 See " Malay Archipelago," vol. ii., chap, xxxviii. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 105 veloping plumage unequalled in beauty, but a beauty which, as to details, is of different kinds, and produced in different ways in different species. To develop " beauty and singularity of plumage " is a character of the group, but not of any one definite kind, to be explained merely by inheritance. Again, we have the very curious horned flies,26 which THE LONG-TAILED BIED OF PARADISE. agree indeed in a common peculiarity, but in one singularly different in detail, in different species, and not known to have any protecting effect. Among plants, also, we meet with the same peculiarity. The great group of Orchids presents a number of species 25 Loc. cit., p. 314. 106 THE GENESIS OF SPECIES. [CHAP. THE RED BIRD OF PARADISE. which offer strange and bizarre approx- imations to differ- ent animal forms, and which have often the appear- ance of cases of mimicry, as it were in an incipient stage. The number of similar instances which could be brought forward from among ani- mals and plants is very great but the examples given are, III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 107 it is hoped, amply sufficient to point toward the conclusion which other facts will, it is thought, establish, viz., that there are causes operating (in the evocation of these har- monious diverging resemblances) other than "Natural Se- THE MAGNIFICENT BIRD OF PARADISE. lection," or heredity, and other even than merely geograph- ical, climatal, or any simply external conditions. 108 THE GENESIS OF SPECIES. [CHAP. Many cases have been adduced of striking likenesses between different animals, not due to inheritance ; but this should be the less surprising, in that the very same indi- vidual presents us with likenesses between different parts of its body (e. g., between the several joints of the back- bone), which are certainly not so explicable. This, how- ever, leads to a rather large subject, which will be spoken of in the eighth chapter of the present work. Here it will be enough to affirm (leaving the proof of the assertion till later) that parts are often homologous which have no di- rect genetic relationship — a fact which harmonizes well with the other facts here given, but which " Natural Se- lection," pure and simple, seems unable to explain. But surely the independent appearance of similar or- ganic forms is what we might expect, a priori, from the independent appearance of similar inorganic ones. As Mr. G. H. Lewes well observes : *6 f< We do not suppose the car- bonates and phosphates found in various parts of the globe — we do not suppose that the families of alkaloids and salts have any nearer kinship than that which consists in the similarity of their elements, and the conditions of their combination. Hence, in organisms, as in salts, morpho- logical identity may be due to a community of casual con- nection, rather than community of descent. " Mr. Darwin justly holds it to be incredible that indi- viduals identically the same should have been produced through Natural Selection from parents specifically dis- tinct, but he will not deny that identical forms may issue from parents genetically distinct, when these parent forms and the conditions "of production are identical. To deny this would be to deny the law of causation." Prof. Huxley has, however, suggested 27 that such min- eral identity may be explained by applying also to minerals 26 Fortnightly Review, New Series, vol. iii. (April, 1868), p. 372. 87 " Lay Sermons," p. 339. III.] INDEPENDENT SIMILARITIES OF STRUCTURE. 109 a law of descent ; that is, by considering such similar forms as the descendants of atoms which inhabited one special part of the primitive nebular cosmos, each considerable space of which may be supposed to have been under the influence of somewhat different conditions. Surely, however, there can be no real parity between the relationship of existing minerals to nebular atoms, and the relationship of existing animals and plants to the ear- liest organisms. In the first place, the latter have pro- duced others by generative multiplication, which mineral atoms never did. In the second, existing animals and plants spring from the living tissues of preceding animals and plants, while existing minerals spring from the chemi- cal affinity of separate elements. Carbonate of soda is not formed, by a process of reproduction, from other carbonate of soda, but directly by the suitable juxtaposition of car- bon, oxygen, and sodium. Instead of approximating animals and minerals in the mode suggested, it may be that they are to be approx- imated in quite a contrary fashion ; namely, by attributing to mineral species an internal innate power. For, as we must attribute to each elementary atom an innate power and tendency to form (under the requisite external con- ditions) certain unions with other atoms, so we may at- tribute to certain mineral species — as crystals — an innate power and tendency to exhibit (the proper conditions being supplied) a definite and symmetrical external form. The distinction between animals and vegetables on the one hand, and minerals on the other, is that, while in the or- ganic world close similarity is the result sometimes of in- heritance, sometimes of direct production independently of parental action, in the inorganic world the latter is the constant and only mode in which such similarity is pro- duced. When we come to consider the relations of species to 110 THE GENESIS OF SPECIES. [CHAP. space — in other words, the geographical distribution of organisms — it will be necessary to return somewhat to the subject of the independent origin of closely-similar forms, in regard to which some additional remarks will be found toward the end of the seventh chapter. In this third chapter an effort has been made to show that while on the Darwinian theory concordant variations are extremely improbable, yet Nature presents us with abundant examples of such ; the most striking of which are, perhaps, the higher organs of sense. Also that an im- portant influence is exercised by conditions connected with geographical distribution, but that a deeper-seated influence is at work, which is hinted at by those special tendencies in definite directions, which are the properties of certain groups. Finally, that these facts, when taken together, afford strong evidence that " Natural Selection " has not been the exclusive or predominant cause of the various or- ganic structural peculiarities. This conclusion has also been reenforced by the consideration of phenomena pre- sented to us by the inorganic world. IV.] MINUTE MODIFICATIONS. Ill CHAPTER IV. MINUTE AND GRADUAL MODIFICATIONS. There are Difficulties as to Minute Modifications, even if not fortuitous.— Examples of Sudden and Considerable Modifications of Different Kinds.— Prof. Owen's View.— Mr. "Wallace.— Prof. Huxley.— Objections to Sudden Changes.— Labyrintbodont.— Potto.— Cetacea.— As to Origin of Bird's Wing.— Tendrils of Climbing Plants.— Animals once supposed to be Connecting Links. — Early Specialization of Structure. — Macrauchenia.— Glyptodon.— Sabre-toothed Tiger.— Conclusion. NOT only are there good reasons against the acceptance of the exclusive operation of " Natural Selection " as the one means of specific origination, but there are difficulties in the way of accounting for such origination by the sole action of modifications which are infinitesimal and minute, whether fortuitous or not. Arguments may yet be advanced in favor of the view that new species have from time to time manifested them- selves with suddenness, and by modifications appearing at once (as great in degree as are those which separate Hip- parion from Equus), the species remaining stable in the intervals of such modifications : by stable being meant that their variations only extend for a certain degree in various directions, like oscillations in a stable equilibrium. This is the conception of Mr. Galton, * who compares the devel- opment of species with a many-facetted spheroid tumbling over from one facet, or stable equilibrium, to another. The existence of internal conditions in animals corresponding 1 " Hereditary Genius, an Inquiry into its Laws," etc. By Francis Galton, F. R. S. (London : Macmillan.) THE GENESIS OF SPECIES. [CHAP. with such facets is denied by pure Darwinians, but it is contended in this work, though not in this chapter, that something may also be said for their existence. The considerations brought forward in the last two chapters, namely, the difficulties with regard to incipient and closely-similar structures respectively, together with paleontological considerations to be noticed later, appear to point strongly in the direction of sudden and consider- able changes. This is notably the case as regards the young oysters already mentioned, which were taken from the shores of England and placed in the Mediterranean, and at once altered their mode of growth and formed prominent diverging rays, like those of the proper Mediter- ranean oyster; as also the twenty-nine kinds of American trees, all differing from their nearest European allies simi- larly— " leaves less toothed, buds and seeds smaller, fewer branchlets," etc. To these may be added other facts given by Mr. Darwin. Thus he says, that " climate, to a certain extent, directly modifies the form of dogs." '" The Rev. R. Everett found that setters at Delhi, though most carefully paired, yet had young with " nostrils more contracted, noses more pointed, size inferior, and limbs more slender." Again, cats at Mombas, on the coast of Africa, have short, stiff hairs, instead of fur ; and a cat at Algoa Bay, when left only eight weeks at Mombas, " un- derwent a complete metamorphosis, having parted with its sandy-colored fur." s The conditions of life seem to pro- duce a considerable effect on horses, and instances are given by Mr. Darwin of pony breeds * having independent- ly arisen in different parts of the world, possessing a cer- tain similarity in their physical conditions. Also changes due to climate may be brought about at once in a second generation, though no appreciable modification is shown 3 " Animals and Plants under Domestication," vol. i., p. 37. 8 Ibid., p. 47. 4 Ibid., p. 52. IV.] MINUTE MODIFICATIONS. 113 by the first. Thus " Sir Charles Lyell mentions that some Englishmen, engaged in conducting the operations of the Real del Monte Company in Mexico, carried out with them some greyhounds, of the best breed, to hunt the hares which abound in that country. It was found that the greyhounds could not support the fatigues of a long chase in this at- tenuated atmosphere, and, before they could come up with their prey, they lay down gasping for breath ; but these same animals have produced whelps, which have grown up, and are not in the least degree incommoded by the want of density in the air, but run down the hares with as much ease as do the fleetest of their race in this country." ' We have here no action of "Natural Selection;" it was not that certain puppies happened accidentally to be capable of enduring more rarefied air, and so survived, but the offspring were directly modified by the action of sur- rounding conditions. Neither was the change elaborated by minute modifications in many successive generations, but appeared at once in the second. With regard once more to sudden alterations of form, Nathusius is said to state positively as to pigs,6 that the re- sult of common experience and of his experiments was that rich and abundant food, given during youth, tends by some direct action to make the head broader and shorter. Curi- ous jaw appendages often characterize Normandy pigs, ac- cording to M. Eudes Deslongchamps. Richardson figures these appendages on the old " Irish greyhound pig," and they are said by Nathusius to appear occasionally in all the long-eared races. Mr. Darwin observes,7 " As no wild pigs are known to have analogous appendages, we have at pres- ent no reason to suppose that their appearance is due to 5 Carpenter's " Comparative Physiology," p. 987, quoted by Mr. J. J. Murphy, " Habit and Intelligence," vol. i., p. 171. 8 " Animals and Plants under Domestication," vol. i., p. 72. 7 Ibid., p. 76. 114 THE GENESIS OF SPECIES. [CHAP. reversion ; and if this be so, we are forced to admit tha somewhat complex, though apparently useless structures may be suddenly developed without the aid of selection." Again, " Climate directly affects the thickness of the skin and hair " of cattle.8 In the English climate an individual Porto Santo rabbit 9 recovered the proper color of its fur in rather less than four years. The effect of the climate of India on the turkey is considerable. Mr. Blyth 10 describes it as being much degenerated in size, " utterly incapable of rising on the wing," of a black color, and " with long pendulous appendages over the beak enormously de- veloped." Mr. Darwin again tells us that there has sud- denly appeared in a bed of common broccoli a peculiar va- riety, faithfully transmitting its newly-acquired and remark- able characters ; " also that there have been a rapid trans- formation and transplantation of American varieties of maize with a European variety ; " that certainly " the An- con and Manchamp breeds of sheep," and that (all but cer- tainly) Niata cattle, turnspit and pug dogs, jumper and frizzled fowls, short-faced tumbler pigeons, hook-billed ducks, etc., and a multitude of vegetable varieties, have suddenly appeared in nearly the same state as we now see them.13 Lastly, Mr. Darwin tells us that there has been an occasional development (in five distinct cases) in Eng- land of the " japanned " or " black-shouldered peacock," (Pavo nigripennis), a distinct species, according to Dr. Sclater,14 yet arising in Sir J. Trevelyan's flock composed entirely of the common kind, and increasing, " to the extinc- tion of the previously-existing breed."16 Mr. Darwin's only explanation of the phenomena (on the supposition of the 8 "Animals and Plants under Domestication," vol. i., p. 71. 9 Ibid., p. 114. 10 Quoted, ibid., p. 274. » Ibid., p. 324. 12 Ibid., p. 322. is Ibid-> voL iLj p< 414g 14 Proc. Zool. Soc. of London, April 24, I860. 15 " Animals and Plants under Domestication," vol. i., p. 291. IV.] MINUTE MODIFICATIONS. 115 species being distinct) is by reversion, owing to a supposed ancestral cross. But he candidly admits, " I have heard of no other such case in the animal or vegetable kingdom." On the supposition of its being only a variety, he observes, "The case is the most remarkable ever recorded of the abrupt appearance of a new form, which so closely re- sembles a true species, that it has deceived one of the most experienced of living ornithologists." As to plants, M. C. Naudin 16 has given the following instances of the sudden origination of apparently perma- nent forms : " The first case mentioned is that of a poppy, which took on a remarkable variation in its fruit — a crown of secondary capsules being added to the normal central capsule. A field of such poppies was grown, and M. Go'p- pert, with seed from this field, obtained still this monstrous form in great quantity. Deformities of ferns are sometimes sought after by fern-growers. They are now always ob- tained by taking spores from the abnormal parts of the monstrous fern ; from which spores ferns presenting the same peculiarities invariably grow. . . . The most remark- able case is that observed by Dr. Godron, of Nancy. In 1861 that botanist observed, among a sowing of Datura tatula, the fruits of which are very spinous, a single indi- vidual of which the capsule was perfectly smooth. The seeds taken from this plant all furnished plants having the character of this individual. The fifth and sixth generations are now growing without exhibiting the least tendency to revert to the spinous form. More remarkable still, when crossed with the normal Datura tatula, hybrids were pro- duced, which, in the second generation, reverted to the original types, as true hybrids do." There are, then, abundant instances to prove that con- siderable modifications may suddenly develop themselves, 16 Extracted by J. J. Murphy, voL i., p. 197, from the Quarterly Jour- nal of Science, of October, 1867, p. 527. 116 THE GENESIS OF SPECIES. [CHAP. either due to external conditions or to obscure internal causes in the organisms which exhibit them. Moreover, these modifications, from whatever cause arising, are capa- ble of reproduction — the modified individuals " breeding true." The question is, whether new species have been de- veloped by non-fortuitous variations which are insignifi- cant and minute, or whether such variations have been comparatively sudden, and of appreciable size and impor- tance ? Either hypothesis will suit the views here main- tained equally well (those views being opposed only to for- tuitous, indefinite variations), but the latter is the more re- mote from the Darwinian conception, and yet has much to be said in its favor. Prof. Owen considers, with regard to specific origina- tion, that natural history " teaches that the change would be sudden and considerable : it opposes the idea that species are transmitted by minute and slow degrees."" " An innate tendency to deviate from parental type, oper- ating through periods of adequate duration," being " the most probable nature, or way of operation of the secondary law, whereby species have been derived one from the other." 18 Now, considering the number of instances adduced of sudden modifications in domestic animals, it is somewhat startling to meet with Mr Darwin's dogmatic assertion that it is " a false belief " that natural species have often originated in the same abrupt manner. The belief may be false, but it is difficult to see how its falsehood can be posi- tively asserted. It is demonstrated by Mr. Darwin's careful weighings and measurements that, though little-used parts in domes- tic animals get reduced in weight and somewhat in size, 17 " Anatomy of Vertebrates," vol. iii., p. 795. 18 Ibid., p. 807. IV.] MINUTE MODIFICATIONS. 117 yet that they show no inclination to become truly " rudi- mentary structures." Accordingly he asserts 19 that such rudimentary parts are formed " suddenly by arrest of de- velopment " in domesticated animals, but in wild animals slowly. The latter assertion, however, is a mere assertion ; necessary, perhaps, for the theory of " Natural Selection," but as yet unproved by facts. But why should not these changes take place suddenly in a state of nature ? As Mr. Murphy says,80 " It may be true that we have no evidence of the origin of wild species in this way. But this is not a case in which negative evi- dence proves any thing. We have never witnessed the origin of a wild species by any process whatever ; and if a species were to come suddenly into being in the wild state, as the Ancon Sheep did under domestication, how could you ascertain the fact ? If the first of a newly-begotten species were found, the fact of its discovery would tell nothing about its origin. Naturalists would register it as a very rare species, having been only once met with, but they would have no means of knowing whether it were the first or the last of its race." To this Mr. Wallace has replied (in his review of Mr. Murphy's work in Nature*1} , by objecting that sudden changes could very rarely be useful, because each kind of animal is a nicely-balanced and adjusted whole, any one sudden modification of which would in most cases be hurt- ful unless accompanied by other simultaneous and harmoni- ous modifications. If, however, it is not unlikely that there is an innate tendency to deviate at certain times, and under certain conditions, it is no more unlikely that that innate tendency should be a harmonious one, calculated to simul- taneously adjust the various parts of the organism to their 19 " Animals and Plants under Domestication," vol. ii., p. 318. 20 "Habit and Intelligence," vol. i., p. 344. 21 See December 2, 1869, vol. i., p. 132. 118 THE GENESIS OF SPECIES. [CHAP. new relations. The objection as to the sudden abortion of rudimentary organs may be similarly met. Prof. Huxley seems now disposed to accept the, at least occasional, intervention of sudden and considerable varia- tions. In his review of Prof. KollikerV3 criticisms, he MUCH EXLAEGBD HORIZONTAL SECTION OP THE TOOTH OF A LABTRINTHODON. himself says, 23 "We greatly suspect that she" (i.e., Na- ture) " does make considerable jumps in the way of varia- tion now and then, and that these saltations give rise to 22 " frber die Darwin'sche Schopfungstheorie : " ein Vortrag, von Kolliker; Leipzig, 1864. «» See " Lay Sermons," p. 342. IV.] MINUTE MODIFICATIONS. 119 some of the gaps which appear to exist in the series of known forms." In addition to the instances brought forward in the second chapter against the minute action of Natural Selec- tion, may be mentioned such structures as the wonderfully folded teeth of the labyrinthodonts. The marvellously com- plex structure of these organs is not merely unaccountable as due to " Natural Selection," but its production by insig- nificant increments of complexity is hardly less difficult to comprehend. Similarly the aborted index of the Potto (Perodicticus) is a structure not likely to have been induced by minute changes; while, as to "Natural Selection," the reduction of the fore-finger to a mere rudiment is inexplicable in- deed ! " How this mutilation can have aided in the strug- HAND OF THE POTTO (PEBODICTICUS), FEOM LIFE. gle for life, we must confess, baffles our conjectures on the subject ; for that any very appreciable gain to the individual can have resulted from the slightly-lessened degree of re- quired nourishment thence resulting (i. e., from the suppres- sion), seems to us to be an almost absurd proposition."24 Again, to anticipate somewhat, the great group of whales (Cetacea) was fully developed at the deposition of the Eocene strata. On the other hand, we may pretty safely conclude that these animals were absent as late as 514 " Anatomy of the Lemuroidea," by James Murie, M. D., and St. George Mivart. Trans. Zool. Soc., March, 1866, p. 91' 120 THE GENESIS OF SPECIES. [CHAP. the latest secondary rocks, so that their development could not have been so very slow, unless geological time is (al- though we shall presently see there are grounds to believe it is not) practically infinite. It is quite true that it is, in general, very unsafe to infer the absence of any animal forms during a certain geological period, because no re- mains of them have as yet been found in the strata then de- posited : but in the case of the Cetacea it is safe to do so ; for, as Sir Charles Lyell remarks,26 they are animals, the re- mains of which are singularly likely to have been preserved had they existed, in the same way that the remains were SKELETON OF A PLESIO8AFEF8. preserved of the Ichthyosauri and Plesiosauri, which ap- pear to have represented the Cetacea during the secondary geological period. As another example, let us take the origin of wings, such as exist in birds. Here we find an arm, the bones of the hand of which are atrophied and reduced in number, as compared with those of most other Vertebrates. Now, if the wing arose from a terrestrial or subaerial organ, this abortion of the bones could hardly have been serviceable — hardly have preserved individuals in the struggle for life. If it arose from an aquatic organ, like the wing of the pen- guin, we have then a singular divergence from the ordinary 25 " Principles of Geology,1' last edition, vol. i., p. 163. IV.] MINUTE MODIFICATIONS. vertebrate fin-limb. In the ichthyosaurus, in the plesio- saurus, in the whales, in the porpoises, in the seals, and in others, we have shortening of the bones, but no reduction in the number either of the fingers or of their joints, which are, on the contrary, multiplied in Cetacea and the ichthyo- saurus. And even in the turtles we have eight carpal bones and five digits, while no finger has less than two phalanges. It is difficult, then, to believe that the Avian limb was developed in any other way than by a compara- tively sudden modification of a marked and important kind. How, once more, can we conceive the peculiar actions of the tendrils of some climbing plants to have been pro- duced by minute modifications ? These, according to Mr. Darwin,28 oscillate till they touch an object, and then em- brace it. It is stated by that observer, that " a thread weighing no more than the thirty-second of a grain, if placed on the tendril of the Passiflora graeilis, will cause it to bend ; and merely to touch the tendril with a twig causes it to bend ; but if the twig is at once removed, the SKELETON OP AN ICHTHYOSAtTRTTS. tendril soon straightens itself. But the contact of other tendrils of the plant, or of the falling of drops of rain, do not produce these effects.27 But some of the zoological and anatomical discoveries of late years tend rather to diminish than to augment the evidence in favor of minute and grad- 06 Quarterly Journal of Science, 1866, pp. 257, 268. 97 "Habit and Intelligence," vol. i., p. 178. 6 122 THE GENESIS OF SPECIES. [CHAP. ual modification. Thus all naturalists now admit that cer- tain animals, which were at one time supposed to be con- necting links between groups, belong altogether to one group, and not at all to the other. For example, the aye- aye28 (Chiromys Madagascar iensis) was till lately con- sidered to be allied to the squirrels, and was often classed with them in the rodent order, principally on account of its dentition ; at the same time that its affinities to the lemurs and apes were admitted. The thorough investigation into THE AYE-AYE. its anatomy that has now been made, demonstrates that it has no more essential affinity to rodents than any other le- mur in e creature has. 28 This animal belongs to the order Primates, which includes man, the apes, and the lemurs. The lemurs are the lower kinds of the order, and differ much from the apes. They have their headquarters in the Island of Madagascar. The aye-aye is a lemur, but it differs singularly from all its congeners, and still more from all apes. In its dentition it strongly approximates to the rodent (rat, squirrel, and guinea-pig) order, as it has two cutting teeth above, and two below,' growing from perma- nent pulps, and in the adult condition has no canines. IV.] MINUTE MODIFICATIONS. 123 Bats were, by the earliest observers, naturally supposed to have a close relationship to birds, and cetaceans to fishes. It is almost superfluous to observe that all now agree that these mammals make not even an approach to either one or other of the two inferior classes. In the same way it has been recently supposed that those extinct flying saurians, the pterodactyls, had an affinity with birds more marked than any other known ani- mals. Now, Iwwever, as has been said earlier, it is con- tended that not only had they no such close affinity, but that other extinct reptiles had a far closer one. The amphibia (i. e., frogs, toads, and efts) were long considered (and are so still by some) to be reptiles, show- ing an affinity to fishes. It now appears that they form with the latter one great group — the ichfchyopsida of Prof. Huxley — which differs widely from reptiles ; while its two component classes (fishes and amphibians) are difficult to separate from each other in a thoroughly satisfactory man- ner. If we admit the hypothesis of gradual and minute mod- ification, the succession of organisms on this planet must have been a progress from the more general to the more special, and no doubt this has been the case in the majority of instances. Yet it cannot be denied that some of the most recently-formed fossils show a structure singularly more generalized than any exhibited by older forms ; while others are more specialized than are any allied creatures of the existing creation. A notable example of the former circumstance is offered by macrauchenia — a hoofed animal, which was at first sup- posed to be a kind of great llama (whence its name) — the llama being a ruminant, which, like all the rest, has two toes to each foot. Now hoofed animals are divisible into two very distinct series, according as the number of func- tional toes on each hind-foot is odd or even. And many 124 THE GENESIS OF SPECIES. [CHAP. other characters are found to go with this obvious one. Even the very earliest Ungulata show this distinction, which is completely developed and marked even in the Eocene palaeotherium and anoplotherium found in Paris by Cuvier. The former of these has the toes odd (perissodac- tyl), the other has them even (artiodactyl). Now, the macrauchenia, from the first relics of it which were found, was thought to belong, as has been said, to the even-toed division. Subsequent discoveries, however, seemed to give it an equal claim to rank among the pe- rissodactyl forms. Others, again, inclined the balance of probability toward the artiodactyl. Finally, it appears that this very recently extinct beast presents a highly-generalized type of structure, uniting in one organic form both artio- dactyl and perissodactyl characters, and that in a manner not similarly found in any other known creature living, or fossil. At the same time the differentiation of artiodactyl and perissodactyl forms existed as long ago as in the period of the Eocene ungulata, and that in a marked de- gree, as has been before observed. Again, no armadillo now living presents nearly so re- markable a specialty of structure as was possessed by the extinct glyptodon. In that singular animal the spinal col- umn had most of its joints fused together, forming a rigid cylindrical rod, a modification, as far as yet known, abso- lutely peculiar to it. In a similar way the extinct machairodus, or sabre- toothed tiger, is characterized by a more highly differ- entiated and specially carnivorous dentition than is shown by any predacious beast of the present day. The special- ization is of this kind : The grinding teeth (or molars) of beasts are divided into premolars and true molars. The premolars are molars which have deciduous vertical prede- cessors (or milk-teeth), and any which are in front of such, i. e., between such and the canine tooth. The true molars IV.] MINUTE MODIFICATIONS. 125 are those placed behind the molars having deciduous verti- cal predecessors. Now, as a dentition becomes more dis- DENTITION OF THE SABRE-TOOTHED TIGER (MACHAIRODUS). tinctly carnivorous, so the hindmost molars and the fore- most premolars disappear. In the existing cats this pro- cess is carried so far that in the upper jaw only one true molar is left on each side. In the machairodus there is no upper true molar at all, while the premolars are reduced to two, there being only these two teeth above, on each side, behind the canine. Now, with regard to these instances of early specializa- tion, as also with regard to the changed estimate of the degrees of affinity between forms, it is not pretended for a moment that such facts are irreconcilable with " Natural Selection." Nevertheless, they point in an opposite direc- tion. Of course not only is it conceivable that certain antique types arrived at a high degree of specialization and then disappeared ; but it is manifest they did do so. Still the fact of this early degree of excessive specialization tells to a certain, however small, extent against a progress through excessively minute steps, whether fortuitous or 126 THE GENESIS OF SPECIES. [CHAP. not ; as also does the distinctness of forms formerly sup- posed to constitute connecting links. For, it must not be forgotten that, if species have manifested themselves generally by gradual and minute modifications, then the absence, not in one, but in all cases, of such connecting links, is a phenomenon which remains to be accounted for. It appears then that, apart from fortuitous changes, there are certain difficulties in the way of accepting ex- tremely minute modifications of any kind, although these difficulties may not be insuperable. Something, at all events, is to be said in favor of the opinion that sudden and appreciable changes have, from time to time, occurred, however they may have been induced. Marked races have undoubtedly so arisen (some striking instances having been here recorded), and it is at least conceivable that such may be the mode of specific manifestation generally, the pos- sible conditions as to which will be considered in a later chapter. V.] SPECIFIC STABILITY. 127 CHAPTER V. AS TO SPECIFIC STABILITY. What is meant by the Phrase "Specific Stability;" such Stability to be expected a priori, or else Considerable Changes at once.— Kapidly-increasing Difficulty of in- tensifying Kace Characters ; Alleged Causes of this Phenomenon ; probably an In- ternal Cause cooperates. — A Certain Definiteness in Variations. — Mr. Darwin ad- mits the Principle of Specific Stability in Certain Cases of Unequal Variability. — The Goose.— The Peacock.— The Guinea-fowl.— Exceptional Causes of Variation under Domestication.— Alleged Tendency to Eeversion.— Instances.— Sterility of Hybrids.— Prepotency of Pollen of same Species, but of Different Kace.— Mortality in Young Gallinaceous Hybrids. — A Bar to Intermixture exists somewhere. — Guinea-pigs.— Summary and Conclusion. As was observed in the preceding chapters, arguments may yet be advanced in favor of the opinion that species are stable (at least in the intervals of their comparatively sudden successive manifestations) ; that the organic world consists, according to Mr. Galton's before-mentioned con- ception, of many faceted spheroids, each of which can re- pose upon any one facet, but, when too much disturbed, rolls over till it finds repose in stable equilibrium upon another and distinct facet. Something, it is here con- tended, may be urged, in favor of the existence of such facets — of such intermitting conditions of stable equilib- rium. A view as to the stability of species, in the intervals of change, has been well expressed in an able article, before quoted from, as follows : * "A given animal or plant ap- pears to be contained, as it were, within a sphere of varia- 1 North British Review, New Series, vol. vii., March, 1867, p. 282. 128 THE GENESIS OF SPECIES. [CHAP tion : one individual lies near one portion of the surface ; another individual, of the same species, near another part of the surface ; the average animal at the centre. Any in- dividual may produce descendants varying in any direction, but is more likely to produce descendants varying toward the centre of the sphere, and the variations in that direction will be greater in amount than the variations toward the surface." This might be taken as the representation of the normal condition of species (i. e., during the periods of re- pose of the several facets of the spheroids), on that view which, as before said, may yet be defended. Judging the organic world from the inorganic, we might expect, a priori, that each species of the former, like crys- tallized species, would have an approximate limit of form, and even of size, and at the same time that the organic, like the inorganic forms, would present modifications in correspondence with surrounding conditions ; but that these modifications would be, not minute and insignificant, but definite and appreciable, equivalent to the shifting of the spheroid on to another facet for support. Mr. Murphy says,2 " Crystalline formation is also de- pendent in a very remarkable way on the medium in which it takes place." " Beudant has found that common salt, crystallizing from pure water, forms cubes ; but if the water contains a little boracic acid, the angles of the cubes are truncated. And the Rev. E. Craig has found that carbon- ate of copper, crystallizing from a solution containing sul- phuric acid, forms hexagonal tubular prisms ; but if a little ammonia is added, the form changes to that of a long, rec- tangular prism, with secondary planes in the angles. If a little more ammonia is added, several varieties of rhombic octahedra appear ; if a little nitric acid is added, the rec- tangular prism appears again. The changes take place not by the addition of new crystals, but by changing the growth 2 " Habit and Intelligence," vol. i., p. 75. V.] SPECIFIC STABILITY. 129 of the original 'ones." These, however, may be said to be the same species, after all ; but recent researches by Dr. H. Charlton Bastian seem to show that modifications in the conditions may result in the evolution of forms so diverse as to constitute different organic species. Mr. Murphy observes 8 that " it is scarcely possible to doubt that the various forms of fungi which are character- istic of particular situations are not really distinct species, but that the same germ will develop into different forms, according to the soil on which it falls ; " but it is possible to interpret the facts differently, and it may be that these are the manifestations of really different and distinct spe- cies, developed according to the different and distinct cir- cumstances in which each is placed. Mr. Murphy quotes Dr. Carpenter * to the effect that " no Puccinia but the Puccinia rosce is found upon rose-bushes, and this is seen nowhere else ; Omygena exigua is said to be never seen but on the hoof of a dead horse ; and Isaria felina has only been observed upon the dung of cats, deposited in humid and obscure situations." He adds, " We can scarce- ly believe that the air is full of the germs of distinct spe- cies of fungi, of which one never vegetates until it falls on the hoof of a dead horse, and another, till it falls on cat's dung in a damp and dark place." This is true, but it does not quite follow that they are necessarily the same species, if, as Dr. Bastian seems to show, thoroughly different and distinct organic forms B can be evolved one from another by modifying the conditions. This observer has brought forward arguments and facts from which it would appear that such definite, sudden, and considerable transforma- tions may take place in the lowest organisms. If such is really the case, we might expect, a priori, to find in the 3 " Habit and Intelligence," vol. i., p. 202. 4 " Comparative Physiology," p. 214, note. 6 See Nature, June and July, 1870, Nos. 35, 36, 37, pp. 170, 193, 219. 130 THE GENESIS OF SPECIES. [CHAP. highest organisms a tendency (much more impeded and rare in its manifestations) to similarly appreciable and sudden changes, under certain stimuli ; but a tendency to continued stability, under normal and ordinary conditions. The proposition that species have, under ordinary circum- stances, a definite limit to their variability, is largely sup- ported by facts brought forward by the zealous industry of Mr. Darwin himself. It is unquestionable that the degrees of variation which have been arrived at in domestic ani- mals have been obtained more or less readily in a moderate amount of time, but that further development in certain desired directions is in some a matter of extreme difficulty, and in others appears to be all but, if not quite, an impos- sibility. It is also unquestionable that the degree of di- vergence which has been attained in one domestic species is no criterion of the amount of divergence which has been attained in another. It is contended on the other side that we have no evidence of any limits to variation other than those imposed by physical conditions, such, e. g., as those which determine the greatest degree of speed possible to any animal (of a given size) moving over the earth's sur- face ; also it is said that the differences in degree of change shown by different domestic animals depend in great meas- ure upon the abundance or scarcity of individuals subjected to man's selection, together with the varying direction and amount of his attention in different cases ; finally, it is said that the changes found in Nature are within the limits to which the variation of domestic animals extends — it being the case, that when changes of a certain amount have oc- curred to a species under nature, it becomes another species, or sometimes two or more other species by divergent varia- tions, each of these species being able again to vary and diverge in any useful direction. But the fact of the rapidly-increasing difficulty found in producing, by over such careful selection, any further ex- V.] SPECIFIC STABILITY. 131 treme in some change already carried very far (such as the tail of the " fantailed pigeon," or the crop of the " pouter"), is certainly, so far as it goes, on the side of the existence of definite limits to variability. It is asserted, in reply, that physiological conditions of health and life may bar any such further development. Thus, Mr. Wallace says6 of these developments : " Variation seems to have reached its limits in these birds. But so it has in nature. The fan- tail has not only more tail-feathers than any of the three hundred and forty existing species of pigeons, but more than any of the eight thousand known species of birds. There is, of course, some limit to the number of feathers of which a tail useful for flight can consist, and in the fan- tail we have probably reached that limit. Many birds have the oesophagus, or the skin of the neck, more or less dilata- ble, but in no known bird is it so dilatable as in the pouter pigeon. Here again the possible limit, compatible with a healthy existence, has probably been reached. In like man- ner, the difference in the size and form of the beak in the va- rious breeds of the domestic pigeon, is greater than that be- tween the extreme forms of beak in the various genera and sub-families of the whole pigeon tribe. From these facts, and many others of the same nature, we may fairly infer that, if rigid selection were applied to any organ, we could, in a comparatively short time, produce a much greater amount of change than that which occurs between species and spe- cies in a state of nature, since the differences which we do produce are often comparable with those which exist be- tween distinct genera or distinct families." But, in a domestic bird like the fantail, where Natural Selection does not come into play, the tail-feathers could hardly be limited by " utility for flight," yet two more tail- feathers could certainly exist in a fancy breed, if " utility for flight " were the only obstacle. It seems probable that the 6 " Natural Selection," p. 293. 132 THE GENESIS OF SPECIES. [CHAP. real barrier is an internal one in the nature of the organism, and the existence of such is just what is contended for in this chapter. As to the differences between domestic races being greater than those between species, or even genera, that is not enough for the argument. For, upon the theory of " Natural Selection " all birds have a common origin, from which they diverged by infinitesimal changes, so that we ought to meet with sufficient changes to warrant the belief that a hornbill could be produced from a humming- bird, proportionate time being allowed. But not only does it appear that there are barriers which oppose change in certain directions, but that there are posi- tive tendencies to development along certain special lines. In a bird which has been kept and studied like the pigeon, it is difficult to believe that any' remarkable spontaneous variations would pass unnoticed by breeders, or that they would fail to be attended to and developed by some one fancier or other. On the hypothesis of indefinite varia- bility, it is then hard to say why pigeons with bills like toucans, or with certain feathers lengthened like those of trogans, or those of birds of paradise, have never been pro- duced. This, however, is a question which may be settled by experiment. Let a pigeon be bred with a bill like a toucan's, and with the two middle tail-feathers lengthened like those of the king-bird of paradise, or even let indi- viduals be produced which exhibit any marked tendency of the kind, and indefinite variability shall be at once con- ceded. As yet, all the changes which have taken place in pigeons are of a few definite kinds only, such as may be well, con- ceived to be compatible with a species possessed of a cer- tain inherent capacity for considerable yet definite varia- tion, a capacity for the ready production of certain degrees of abnormality, which then cannot be further increased. Mr. Darwin himself has already acquiesced in the prop- V.] SPECIFIC STABILITY. 133 osition here maintained, inasmuch as he distinctly affirms the existence of a marked internal barrier to change in cer- tain cases. And if this is admitted in one case, the prin- ciple is conceded, and it immediately becomes probable that such internal barriers exist in all, although enclosing a much larger field for variation in some cases than in others. Mr. Darwin abundantly demonstrates the variabil- ity of dogs, horses, fowls, and pigeons, but he none the less shows clearly the very small extent to which the goose, the peacock, and the guinea-fowl have varied.7 Mr. Darwin at- tempts to explain this fact as regards the goose by the ani- mal being valued only for food and feathers, and from no pleasure having been felt in it on other accounts. He adds, however, at the end the striking remark,8 which concedes the whole position, " but the goose seems to have a sin- gularly inflexible organization" This is not the only place in which such expressions are used. He elsewhere makes use of phrases which quite harmonize with the con- ception of a normal specific constancy, but varying greatly and suddenly at intervals. Thus he speaks 9 of a whole organization seeming to have become plastic, and tending to depart from the parental type. That different organ- isms should have different degrees of variability, is only what might have been expected a priori from the exist- ence of parallel differences in inorganic species, some of these having but a single form, and others being poly- morphic. To return to the goose, however, it may be remarked that it is at least as probable that its fixity of character is the cause of the neglect, as the reverse. It is by no means unfair to assume that had the goose shown a tendency to vary similar in degree to the tendency to variation of the 7 " Animals and Plants under Domestication," vol. L, pp. 289-295. 8 " Origin of Species," 5th edit., 1869, p. 45. ' 9 Ibid., p. 13. 134 THE GENESIS OF SPECIES. [CHAP. fowl or pigeon, it would have received attention at once on that account. As to the peacock it is excused on the pleas (1), that the individuals maintained are so few in number, and (2) that its beauty is so great it can hardly be improved. But the individuals maintained have not been too few for the in- dependent origin of the black-shouldered form, or for the supplanting of the commoner one by it. As to any neglect in selection, it can hardly be imagined that with regard to this bird (kept as it is all but exclusively for its beauty), any spontaneous beautiful variation in color or form would have been neglected. On the contrary, it would have been seized upon with avidity and preserved with anxious care. Yet apart from the black-shouldered and white varieties, no tendency to change has been known to show itself. As to its being too beautiful for improvement, that is a proposi- tion which can hardly be maintained. Many consider the Javan bird as much handsomer than the common peacock, and it would be easy to suggest a score of improvements as regards either species. The guinea-fowl is excused, as being " no general favor- ite, and scarcely more common than the peacock ;" but Mr. Darwin himself shows and admits that it is a noteworthy instance of constancy under very varied conditions. These instances alone (and there are yet others) seem sufficient to establish the assertion that degree of change is different in different domestic animals. It is, then, some- what unwarrantable in any Darwinian to assume that all wild animals have a capacity for change similar to that ex- isting in some of the domestic ones. It seems more reason- able to assert the opposite, namely, that if, as Mr. Darwin says, the capacity for change is different in different domes- tic animals, it must surely be limited in those which have it least, and a fortiori limited in wild animals. Indeed, it cannot be reasonably maintained that wild V.] SPECIFIC STABILITY. 135 species certainly vary as much as do domestic races ; it is possible that they may do so, but at least this has not been yet shown. Indeed, the much greater degree of variation among domestic animals than among wild ones is asserted over and over again by Mr. Darwin, and his assertions are supported by an overwhelming mass of facts and instances. Of course it may be asserted that a tendency to indefi- nite change exists in all cases, and that it is only the circum- stances and conditions of life which modify the effects of this tendency to change so as to produce such different results in different cases. But assertion is not proof, and this assertion has not been proved. Indeed, it may be equally asserted (and the statement is more consonant with some of the facts given), that domestication in certain an- imals induces and occasions a capacity for change which is wanting in wild animals — the introduction of new causes occasioning new effects! For, though a certain degree of variability (normally, in all probability, only oscillation) ex- ists in all organisms, yet domestic ones are exposed to new and different causes of variability, resulting in such striking divergencies as have been observed. Not even in this latter case, however, is it necessary to believe that the variability is indefinite, but only that the small oscillations become in certain instances intensified into large and conspicuous ones. Moreover, it is possible that some of our domestic animals have been in part chosen and domesticated through possess- ing variability in an eminent degree. That each species exhibits certain oscillations of struct- ure is admitted on all hands. Mr. Darwin asserts that this is the exhibition of a tendency to vary which is absolutely indefinite. If this indefinite variability does exist, of course no more need be said. But we have seen that there are arguments a priori and a posteriori against it, while the occurrence of variations in certain domestic animals greater in degree than the differences between many wild species, 136 THE GENESIS OF SPECIES. [CHAP. is no argument in favor of its existence, until it can be shown that the causes of variability in the one case are the same as in the other. An argument against it, however, may be drawn from the fact that certain animals, though placed under the influence of those exceptional causes of variation to which domestic animals are subject, have yet never been known to vary, even in a degree equal to that in which certain wild kinds have been ascertained to vary. In addition to this immutability of character in some animals, it is undeniable that domestic varieties have little stability, and much tendency to reversion, whatever be the true explanation of such phenomena. In controverting the generally received opinion as to " reversion," Mr. Darwin has shown that it is not all breeds which in a few years revert to the original form ; but he has shown no more. Thus, the feral rabbits of Porto Santo, Jamaica, and the Falkland Islands, have not yet so reverted in those several localities.10 Nevertheless, a Porto Santo rabbit brought to England reverted in a manner the most striking, recovering the proper color of its fur " in rather less than four years." ] Again, the white silk fowl, in our climate, " reverts to the ordinary color of the common fowl in its skin and bones, due care having been taken to pre- vent any cross." ] This reversion taking place in spite of careful selection, is very remarkable. Numerous other instances of reversion are given by Mr. Darwin, both as regards plants and animals ; among others, the singular fact of bud reversion.13 The curiously-recurr- ring development of black sheep, in spite of the most care- ful breeding, may also be mentioned, though, perhaps, reversion has no part in the phenomenon. These facts seem certainly to tell in favor of limited 10 " Animals and Plants under Domestication," vol. L, p. 115. 11 Ibid., vol. L, p. 114. 12 Ibid., vol. i., p. 243 13 Ibid., vol. ii., p. 361. II.] SPECIFIC STABILITY. 137 variability, while the cases of non-reversion do not contra- dict it, as it is not contended that all species have the same tendency to revert, but rather that their capacities in this respect, as well as for change, are different in different kinds, so that often reversion may only show itself at the end of very long periods indeed. Yet some of the instances given as probable or possible causes of reversion by Mr. Darwin, can hardly be such. He cites, for example, the occasional presence of supernumerary digits in man.14 For this notion, however, he is not re- sponsible, as he rests his remark on the authority of a pas- sage published by Prof. Owen. Again, he refers 1B to " the greater frequency of a monster proboscis in the pig than in any other animal." But with the exception of the pe- culiar muzzle of the Saiga (or European antelope), the only known proboscidian Ungulates are the elephants and tapirs, and to neither of these has the pig any close affinity. It is rather in the horse than in the pig that we might look for the appearance of a reversionary proboscis, as both the elephants and the tapirs have the toes of the hind-foot of an odd number. It is true that the elephants are generally considered to form a group apart from both the odd and the even toed Ungulata. But of the two, their affinities with the odd-toed division are more marked. 16 Another argument in favor of the, at least intermitting, constancy of specific forms and of sudden modification, may be drawn from the absence of minute transitional forms, but this will be considered in the next chapter. 14 "Animals and Plants under Domestication," vol. ii., p. 16. 15 Ibid., vol. ii., p. 57. 16 This has been shown by my late friend Mr. H. N. Turner, Jr., in an excellent paper by him in the u Proceedings of the Zoological Society for 1849," p. 147. The untimely death, through a dissecting wound, of this most promising young naturalist, was a very great loss to zoological 138 THE GENESIS OF SPECIES. [CHAP. It remains now to notice in favor of specific stability, that the objection drawn from physiological difference be- tween " species " and " races " still exists unrefuted. Mr. Darwin freely admits difficulties regarding the ste- rility of different species when crossed, and shows satis- factorily that it could never have arisen from the action of " Natural Selection." He remarks 17 also : " With some few exceptions, in the case of plants, domesticated varieties, such as those of the dog, fowl, pigeon, several fruit-trees, and culinary vegetables, which differ from each other in ex- ternal characters more than many species, are perfectly fer- tile when crossed, or even fertile in excess, while closely- allied species are almost invariably in some degree sterile." Again, after speaking of " the general law of good being derived from the intercrossing of distinct individuals of the same species," and the evidence of the pollen of a distinct variety or race is prepotent over a flower's own pollen, adds the very significant remark, 18 " When distinct species are crossed, the case is directly the reverse, for a plant's own pollen is almost always prepotent over foreign pollen." Again he adds : " "I believe from observations commu- nicated to me by Mr. Hewitt, who has had great experience in hybridizing pheasants and fowls, that the early death of the embryo is a very frequent cause of sterility in first crosses. Mr. Salter has recently given the results of an examination of about five hundred eggs produced from various crosses between three species of Gallus and their hybrids. The majority of these eggs had been fertilized, and in the ma- jority of the fertilized eggs the embryos either had been partially developed and had then aborted, or had become nearly mature, but the young chickens had been unable to break through the shell. Of the chickens which were born, 17 "Animals and Plants under Domestication," vol. ii., p. 189. is "Origin of Species," 6th edit., 1869, p. 115. 19 Ibid., p. 322. V.] SPECIFIC STABILITY. 139 more than four-fifths died within the first few days, or at latest weeks, ' without any obvious cause, apparently from mere inability to live,' so that from five hundred eggs only twelve chickens were reared. The early death of hybrid embryos probably occurs in like manner with plants, at least it is known that hybrids raised from very distinct species are sometimes weak and dwarfed, and perish at an early age, of which fact Max Wichura has recently given some striking cases with hybrid willows." Mr. Darwin objects to the notion that there is any special sterility imposed to check specific intermixture and change, saying,20 " To grant to species the special power of producing hybrids, and then to stop their further propa- gation by different degrees of sterility, not strictly related to the facility of the first union between their parents, seems a strange arrangement." But this only amounts to saying that the author him- self would not have so acted had he been the Creator. A "strange arrangement" must be admitted anyhow, and all who acknowledge teleology at all, must admit that the strange arrangement was designed. Mr. Darwin says, as to the sterility of species, that the cause lies exclusively in their sexual constitution ; but all that need be affirmed is that sterility is brought about somehow, and it is undenia- ble that " crossing" is checked. All that is contended for is that there is a bar to the intermixture of species, but not of breeds ; and if the conditions of the generative products are that bar, it is enough for the argument, no special kind of barring action being contended for. He, however, attempts to account for the modification of the sexual products of species as compared with those of varieties, by the exposure of the former to more uniform conditions during longer periods of time than those to which varieties are exposed, and that as wild animals, when cap- 20 " Origin of Species," 5th edit., 1869, p. 314. 140 THE GENESIS OF SPECIES. [CHAP. tured, are often rendered sterile by captivity, so the influ- ence of union with another species may produce a similar effect. It seems to the author an unwarrantable assump- tion that a cross with what, on the Darwinian theory, can only be a slightly-diverging descendant of a common par- ent, should produce an effect equal to that of captivity, and consequent change of habit, as well as considerable modification of food. No clear case has been given by Mr. Darwin in which mongrel animals, descended from the same undoubted spe- cies, have been persistently infertile inter se / nor any clear case in which hybrids between animals, generally admitted to be distinct species, have been continually fertile inter se. It is true that facts are brought forward tending to establish the probability of the doctrine of Pallas, that spe- cies may sometimes be rendered fertile by domestication. But even if this were true, it would be no approximation toward proving the converse, i. e., that races and varieties may become sterile when wild. And whatever may be the preference occasionally shown by certain breeds to mate with their own variety, no sterility is recorded as resulting from unions with other varieties. Indeed, Mr. Darwin re- marks,21 " With respect to sterility from' the crossing of domestic races, I know of no well-ascertained case with ani- mals. This fact (seeing the great difference in structure between some breeds of pigeons, fowls, pigs, dogs, etc.) is extraordinary when contrasted with the sterility of many closely-allied natural species when crossed." It has been alleged that the domestic and wild guinea- pig do not breed together, but the specific identity of these forms is very problematical. Mr. A. D. Bartlett, superin- tendent of the Zoological Gardens, whose experience is so great, and observation so quick, believes them to be de- cidedly distinct species. 21 " Animals and Plants under Domestication," voL ii., p. 104. V.] SPECIFIC STABILITY. 141 Thus, then, it seems that a certain normal specific sta- bility in species, accompanied by occasional sudden and considerable modifications, might be expected a priori from what we know of crystalline inorganic forms and from what we may anticipate with regard to the lowest organic ones. This presumption is strengthened by the knowledge of the increasing difficulties which beset any attempt to indefinitely intensify any race characteristics. The obsta- cles to this indefinite intensification, as well as to certain lines of variation in certain cases, appear to be not only external, but to depend on internal causes or an internal cause. We have seen that Mr. Darwin himself implicitly admits the principle of specific stability in asserting the singular inflexibility of the organization of the goose. We have also seen that it is not fair to conclude that all wild races can vary as much as the most variable domestic ones. It has also been shown that there are grounds for believing in a tendency to reversion generally, as it is distinctly pres- ent in certain instances. Also that specific stability is con- firmed by the physiological obstacles which oppose them- selves to any considerable or continued intermixture of species, while no such barriers oppose themselves to the blending of varieties. All these considerations taken to- gether may fairly be considered as strengthening the belief that specific manifestations are relatively stable. At the same time the view advocated in this book does not depend upon, and is not identified with, any such stability. All that the author contends for is that specific manifestation takes place along certain lines, and according to law, and riot in an exceedingly minute, indefinite, and fortuitous manner. Finally, he cannot but feel justified, from all that has been brought forward, in reiterating the open- ing assertion of this chapter that something is still to be said for the view which maintains that species are stable, at least in the intervals of their comparatively rapid suc- cessive manifestations. 142 THE GENESIS OF SPECIES. [CHAP. CHAPTER VI. SPECIES AND TIME. Two Relations of Species to Time.— No Evidence of Past Existence of Minutely- intermediate Forms when such might be expected a priori. — Bats, Pterodac- tyls, Dinosauria, and Birds.— Ichthyosauria, Chelonia, and Anoura.— Horse An- cestry.—Labyrinthodonts and Trilobites.— Two Subdivisions of the Second Eela- tion of Species to Time. — Sir William Thomson's Views. — Probable Period re- quired for Ultimate Specific Evolution from Primitive Ancestral Forms. — Geo- metrical Increase of Time required for Eapidly-multiplying Increase of Structural Differences. — Proboscis Monkey. — Time required for Deposition of Strata neces- sary for Darwinian Evolution. — High Organization of Silurian Forms of Life. — Absence of Fossils in Oldest Eocks. — Summary and Conclusion. Two considerations present themselves with regard to the necessary relation of species to time if the theory of "Natural Selection" is valid and sufficient. The first is with regard to the evidences of the past ex- istence of intermediate forms, their duration and succession. The second is with regard to the total amount of time required for the evolution of all organic forms from a few original ones, and the bearing of other sciences on this question of time. As to the first consideration, evidence is as yet against the modification of species by " Natural Selection " alone, because not only are minutely transitional forms generally absent, but they are absent in cases where wTe might cer- tainly a priori have expected them to be present. Now it has been said : 1 "If Mr. Darwin's theory be true, the number of varieties differing one from another a 1 North British Review, New Series, vol. vii., March, 1867, p. 317. VL] SPECIES AND TIME. 143 very little must have been indefinitely great, so great indeed as probably far to exceed the number of individuals which have existed of any one variety. If this be true, it would be more probable that no two specimens preserved as fossils should be of one variety than that we should find a great many specimens collected from a very few varieties, provided, of course, the chances of preservation are equal for all individuals." " It is really strange that vast num- bers of perfectly similar specimens should be found, the chances against their perpetuation as fossils are so great ; but it is also very strange that the specimens should be so exactly alike as they are, if, in fact, they came and . vanished by a gradual change." A frl& QMM Mr. Darwin attempts 2 to show cause why we should believe a priori that intermediate varieties would exist in lesser numbers than the more extreme forms ; but though they would doubtless do so sometimes, it seems too much to assert that they would do so generally, still less univer- sally. Now little less than universal and very marked inferiority in numbers would account for the absence of certain series of minutely intermediate fossil specimens. The mass of paleontological evidence is indeed overwhelm- ingly against minute and gradual modification. It is true that when once an animal has obtained powers of flight its means of diffusion are indefinitely increased, and we might expect to find many relics of an aerial form and few of its antecedent state — with nascent wings just commencing their suspensory power. Yet had such a slow mode of origin, as Darwinians contend for, operated exclusively in all cases, it is absolutely incredible that birds, bats, and pterodactyls, should have left the remains they have, and yet not a single relic be preserved in any one instance of any of these different forms of wing in their incipient and relatively imperfect functional condition ! 2 "Origin of Species," 5th edit., 1869, p. 212. 144 THE GENESIS OF SPECIES. [CHAP. Whenever the remains of bats have been found they have presented the exact type of existing forms, and there is as yet no indication of the conditions of an incipient ele- vation from the ground. The pterodactyls, again, though a numerous group, are all true and perfect pterodactyls, though surely some of WING-BONES OF PTERODACTYL, BAT, AND BIRD. the many incipient forms, which on the Darwinian theory have existed, must have had a good chance of preservation. As to birds, the only notable instance in which discov- eries recently made appear to fill up an important hiatus, is the interpretation given by Prof. Huxley 3 to the remains of Dinosaurian reptiles, and which were noticed in the third chapter of this work. The learned professor has (as also has Prof. Cope in America) shown that in very impor- tant and significant points the skeletons of the Iguanodon and of its allies approach very closely to that existing in the ostrich, emeu, rhea, etc. He has given weighty rea- sons for thinking that the line of affinity between birds and 3 See also the Popular Science Review for July, 1868. VI.] SPECIES AND TIME. 145 reptiles passes to the birds last named from the Dinosauria rather than from the Pterodactyls, through Archeopteryx- like forms to the ordinary birds. Finally, he has thrown out the suggestion that the celebrated footsteps left by some extinct three-toed creatures on the very ancient sand- stone of Connecticut were made, not, as hitherto supposed, by true birds, but by more or less ornithic reptiles. But even supposing all that is asserted or inferred on this sub- ject to be fully proved, it would not approach to a demon- stration of specific origin by minute modification. And though it harmonizes well with " Natural Selection," it is equally consistent with the rapid and sudden development of new specific forms of life. Tndeed, Prof. Huxley, with a laudable caution and moderation too little observed by some Teutonic Darwinians, guarded himself carefully from any imputation of asserting dogmatically the theory of " Natural Selection," while upholding fully the doctrine of evolution. But, after all, it is by no means certain, though very probable, that the Connecticut footsteps were made by very ornithic reptiles, or extremely sauroid birds. And it must not be forgotten that a completely carinate 4 bird (the Archeopteryx) existed at a time, when, as yet, we have no evidence of some of the Dinosauria having come into being. Moreover, if the remarkable and minute similarity of the coracoid of a pterodactyl to that of a bird be merely the result of function, and no sign of genetic affinity, it is not inconceivable that pelvic and leg resemblances of Dinosau- ria to birds may be functional likewise, though such an ex- planation is, of course, by no means necessary to support the view maintained in this book. But the number of forms represented by many individ- uals, yet by no transitional ones, is so great, that only two 4 A bird with a keeled breastbone, such as almost all existing birds 146 THE GENESIS OF SPECIES. [CHAP. or three can be selected as examples. Thus those remark- able fossil reptiles, the Ichthyosauria and Plesiosauria, ex- THE AECHEOPTEKYX (OF THE OOLITE STRATA). tended, through the secondary period, probably over the greater part of the globe. Yet no single transitional form has yet been met with in spite of the multitudinous indi- viduals preserved. Again, with their modern representa- SKELETON OF AN ICHTHYOSAURUS. tives, the Cetacea, one or two aberrant forms alone have been found, but no series of transitional ones indicating minutely the line of descent. This group, the whales, is a very marked one, and it is curious, on Darwinian principles, VI.] SPECIES AND TIME. 147 that so few instances tending to indicate its mode of origin should have presented themselves. Here, as in the bats, we might surely expect that some relics of unquestionably incipient stages of its development would have been left. SKELETON OF A PLESIOSAUBIT8. The singular order Chelonia, including the tortoises, turtles, and terrapins (or fresh- water tortoises), is another instance of an extreme form without any, as yet known, transitional stages. Another group may be finally men- tioned, viz., the frogs and toads, anourous Batrachians, of which we have at present no relic of any kind linking them on to the Eft group on the one hand, or to reptiles on the other. The only instance in which an approach toward a series of nearly-related forms has been obtained is the existing horse, its predecessor Hipparion, and other extinct forms. But even here there is no proof whatever of modification by minute and infinitesimal steps ; a fortiori no approach to a proof of modification by " Natural Selection," acting upon indefinite fortuitous variations. On the contrary, the series is an admirable example of successive modification in one special direction along one beneficial line, and the teleologist must here be allowed to consider that one mo- tive of this modification (among probably an indefinite number of motives inconceivable to us) was the relation- 148 THE GENESIS OF SPECIES. [CHAP. ship in which the horse was to stand to the human inhabit- ants of this planet. These extinct forms, as Prof. Owen remarks,6 " differ from each other in a greater degree than do the horse, zebra, and ass," which are not only good zoological species as to form, but are species physiologi- cally, i. e., they cannot produce a race of hybrids fertile inter se. As to the mere action of surrounding conditions, the same professor remarks : a *' Any modification affecting the density of the soil might so far relate to the changes of limb-structure, as that a foot with a pair of small hoofs, dangling by the sides of the large one, like those behind the cloven hoof of the ox, would cause the foot of Hip- parion, e. g., and a fortiori the broader based three-hoofed foot of the Palaeothere, to sink less deeply into swampy soil, and be more easily withdrawn than the more concen- tratively simplified and specialized foot of the horse. Rhi- noceroses and zebras, however, tread together the arid plains of Africa in the present day ; and the horse has multiplied in that half of America where two or more kinds of tapir still exist. That the continents of the Eocene or Miocene periods were less diversified in respect of swamp and sward, pampas, or desert, than those of the Pliocene period, has no support from observation or anal- ogy." Not only, however, do we fail to find any traces of the incipient stages of numerous very peculiar groups of ani- mals, but it is undeniable that there are instances which appeared at first to indicate a gradual transition, yet which instances have been shown, by further investigation and dis- covery, not to indicate truly any thing of the kind. Thus at one time the remains of Labyrinthodonts, which, up till then, had been discovered, seemed to justify the opinion that, as time went on, forms had successively appeared 6 " Anatomy of Vertebrates," vol. iii., p. 792. 6 Ibid., p. 793. VI.] SPECIES AND TIME. 149 with more and more complete segmentation and ossifica- tion of the backbone, which, in the earliest forms, was (as it is in the lowest fishes now) a soft, continuous rod or notochord. Now, however, it is considered probable that the soft backboned Labyrinthodon Archegosaurus was an immature or larval form,7 while Labyrinthodonts, with com- pletely developed vertebrae, have been found to exist among the very earliest forms yet discovered. The same may be said regarding the eyes of the trilobites, some of the oldest forms having been found as well furnished in that respect as the very last of the group which has left its remains ac- cessible to observation. Such instances, however, as well as the way in which marked and special forms (as the Pterodactyls, etc., before referred to) appear at once in and similarly disappear from the geological record, are of course explicable on the Dar- winian theory, provided a sufficiently enormous amount of past time be allowed. The alleged extreme, and probably great, imperfection of that record may indeed be pleaded in excuse. But it is an excuse.8 Nor is it possible to deny 7 As a tadpole is the larval form oi a frog. 8 As Prof. Huxley, with his characteristic candor, fully admitted in his lecture on the Dinosauria before referred to. 150 THE GENESIS OF SPECIES. [CHAP. si the a priori probability of the preservation of at least a few minutely transitional forms in some instances if every species without exception has arisen exclusively by such minute and gradual transitions. It remains, then, to turn to the other considerations with regard to the relation of species to time : namely (1), as to the total amount of time allowable by other sciences for organic evolution ; and (2) the proportion existing, on Darwinian principles, between the time anterior to the ear- lier fossils, and the time since ; as evidenced by the pro- portion between the amount of evolutionary change during the latter epoch and that which must have occurred ante- riorly. Sir William Thomson has lately * advanced arguments from three distinct lines of inquiry, and agreeing in one ap- proximate result. The three lines of inquiry were — 1. The action of the tides upon the earth's rotation. 2. The prob- able length of time during which the sun has illuminated this planet ; and 3. The temperature of the interior of the earth. The result arrived at by these investigations is a conclusion that the existing state of things on the earth, life on the earth, all geological history showing continuity of life, must be limited within some such period of past time as one hundred million years. The first question which suggests itself, supposing Sir W. Thomson's views to be correct, is, Is this period any thing like enough for the evolution of all organic forms by " Natural Selection ? " The second is, Is this period any thing like enough for the deposition of the strata which must have been deposited if all organic forms have been evolved by minute steps, ac- cording to the Darwinian theory ? In the first place, as to Sir William Thomsom's views, the ^author of this book cannot presume to advance any opin- ion ; but the fact that they have not been refuted, pleads cal Society of Glasgow," vo 9 <' Transactions of the Geo •f- - • ./, < VI.] SPECIES AND TIME. 151 strongly in their favor when we consider how much they tell against the theory of Mr. Darwin. The last-named author only remarks that " many of the elements in the cal- culation are more or less doubtful." 10 and Prof. Huxley " does not attempt to refute Sir W. Thomson's arguments, but only to show cause for suspense of judgment, inasmuch as the facts may be capable of other explanations. Mr. Wallace, on the other hand,13 seems more disposed to accept them, and, after considering Sir William's objec- tions and those of Mr. Croll, puts the probable date of the beginning of the Cambrian deposits 13 at only twenty-four/ million years ago. On the other hand, he seems to consid^ er that specific change has been more rapid than generally \ supposed, and exceptionally stable during the last score or / so of thousand years. v Now, first, with regard to the time required for the evo- -fa i, lution of all organic forms by merely accidental, minute, ^ and fortuitous variations, the useful ones of which have fjf* ' / been preserved. ^ *4Ct***1 ^ Mr. Murphy 14 is distinctly of opinion that there has not fr fl been time enough. He says : " I am inclined to think that £^ 0 geological time is too short for the evolution of the higher/A^ forms of life out of the lower by that accumulation of im- perceptibly slow variations, to which alone Darwin cribes the whole process." " Darwin justly mentions the greyhound as being equal* .to any natural species in the perfect coordination of its parts, £ all adapted for extreme fleetness and for running down weak prey.' '' " Yet it is an artificial species (and not physiologically a species at alt), formed by long-con- 10 « Origin of Species," 5th edit., p. 354. 11 See his address to the Geological Society, on February 19, 1869. 12 See Nature, vol. L, p. 399, February 17, 1870. 13 Ibid., vol. i., p. 454. 14 " Habit and Intelligence," vol. i., p. 344. 152 THE GENESIS OF SPECIES. [CHAP. tinued selection under domestication; and there is no reason to suppose that any of the variations which have been selected to form it have been other than gradual and almost imperceptible. Suppose that it has taken five hun- dred years to form the greyhound out of his wolf-like an- , cestor. This is a mere guess, but it gives the order of the magnitude." Now, if so, " how long would it take to ob- tain an elephant from a protozoon, or even from a tadpole- like fish ? Ought it not to take much more than a million times as long ? " " Mr. Darwin 16 would compare with the natural origin of a species " unconscious selection, that is, the preservation of the most useful or beautiful animals, with no intention of modifying the breed." He adds : " But by this process of unconscious selection, various breeds have been sensibly changed in the course of two or three centuries." " Sensibly changed ! " but not formed into " new spe- cies." Mr. Darwin, of course, could not mean that species generally change so rapidly, which would be strangely at variance with the abundant evidence we have of the stabil- ity of animal forms as represented on Egyptian monuments and as shown by recent deposits. Indeed, he goes on to say : " Species, however, probably change much more slow- ly, and within the same country only a few change at the same time. This slowness follows from all the inhabitants of the same country being already so well adapted to each other, that places in the polity of Nature do not occur until after long intervals, when changes of some kind in the physical conditions, or through immigration, have occurred, and individual differences and variations of the right na- ture, by which some of the inhabitants might be better fitted to their new places under altered circumstances, might not at once occur." This is true, and not only will 15 " Habit and Intelligence," vol. i., p. 345. 16 " Origin of Species," 5th edit, p. 353. VI.] SPECIES AND TIME. 153 these changes occur at distant intervals, but it must be borne in mind that in tracing back an animal to a remote ^ ancestry, we pass through modifications of such rapidly-in- J creasing number and importance that a geometrical pro- ' gression can alone indicate the increase of periods which such profound alterations would require for their evolution through " Natural Selection " only. Thus let us take for an example the proboscis monkey of Borneo (Semnopithecus nasalis). According to Mr. Dar- win's own opinion, this form might have been " sensibly changed " in the course of two or three centuries. Accord- ing to this, to evolve it as a true and perfect species one thousand years would be a very moderate period. Let ten thousand years be taken to represent approximately the period of substantially constant conditions, during which no considerable change would be brought about. Now, it one thousand years may represent the period required for the evolution of the species S. nasalis, and of the other species of the genus Semnopithecus, ten times that period should, I think, be allowed for the differentiation of that genus, the African Cercopithecus, and the other genera of the family Simiidae — the differences between the genera being certainly more than tenfold greater than those between the species of the same genus. Again, we may perhaps interpose a period of ten thousand years' com- parative repose. For the differentiation of the families Simiidae and Cebidae — so very much more distinct and different than any two genera of either family — a period ten times greater should, I believe, be allowed than that required for the evolution of the subordinate groups. A similarly increasing ratio should be granted for the successive developments of the difference between the Lemuroid and the higher forms of primates ; for those between the original primate and other root-forms of placental mammals ; for those between 154 THE GENESIS OF SPECIES. [Cr. primary placental and implacental mammals, and perhaps also for the divergence of the most ancient stock of these and of the monotremes, for in all these cases modifications of structure appear to increase in complexity in at least that ratio. Finally, a vast period must be granted for the development of the lowest mammalian type from the prim- itive stock of the whole vertebrate sub-kingdom. Sup- posing this primitive stock to have arisen directly from a / very lowly-organized animal indeed (such as a nematoid : worm, or an ascidian, or a jelly-fish), yet it is not easy to believe that less than two thousand million years would be required for the totality of animal development by no other means than minute, fortuitous, occasional, and inter- mitting variations in all conceivable directions. If this be even an approximation to the truth, then there seem to be strong reasons for believing that geological time is not suffi- cient for such a process. i' The second question is, whether there has been time ugh for the deposition of the strata which must have n deposited, if all organic forms have been evolved rding to the Darwinian theory ? Now this may at first seem a question for geologists only, but, in fact, in this matter geology must in some re- " spects rather take its time from zoology than the reverse; Mr. Darwin's theory be true, past time, down to the deposition of the Upper Silurian strata, can have been but a very small fraction of that during which strata have been deposited. For when those Upper Silurian strata were / formed, organic evolution had already run a great part of \ - its course, perhaps the longest, slowest, and most difficult j part of that course. At that ancient epoch, not only were the vertebrate, molluscous,' and arthropod types distinctly and clearly differentiated, but highly-developed forms had been pro- ll ^uce(^ *n eacn °f tnese sub-kingdoms. Thus in the Verte- VI.] SPECIES AND. TIME. 155 brata there were fishes not belonging to the lowest but to the very highest groups which are known to have ever been developed, namely, the Elasmobranchs (the highly-organ- ized sharks and rays), and the Ganoids, a group now poorly represented, but for which the sturgeon may stand as a type, and which in many important respects more nearly resemble higher Vertebrata than do the ordinary or CUTTLE-FISH. A. Ventral aspect. B. Dorsal aspect. osseous fishes. Fishes in which the ventral fins are placed in front of the pectoral ones (i.e., jugular fishes) have been generally considered to be comparatively modern forms. But Prof. Huxley has kindly informed me that he has dis- covered a jugular fish in the Permian deposits. Among the molluscous animals we have members of the very highest known class, namely, the Cephalopods, or cuttle-fish class ; and among articulated animals we find Trilobites and Eurypterida, which do not belong to any 156 THE GENESIS OF SPECIES. [CHAP. incipient worm-like group, but are distinctly differentiated Crustacea of no low form. We have in all these animal types nervous systems differentiated on distinctly different patterns, fully-formed organs of circulation, digestion, excretion, and generation, complexly-constructed eyes and other sense organs ; in fact, all the most elaborate and complete animal structures built up, and not only once, for in the fishes and mollusca we have (as described in the third chapter of this work) the coincidence of the independently-developed organs of sense attaining a nearly similar complexity in two quite distinct forms. If, then, so small an advance has been made in fishes, mollusks, and anthropods, since the Upper Silurian deposits, it will probably be within the mark to consider that the period before those deposits (during which all these organs would, on the Darwinian theory, have slowly built up their different perfections and complexities) occupied time at least a hundredfold greater. Now it will be a moderate computation to allow 25,000,000 years for the deposition of the strata down to and including the Upper Silurian. If, then, the evolution- ary work done during this deposition only represents a hundredth part of the sum total, we shall require 2,500,000,000 (two thousand five hundred million) years for the complete development of the whole animal kingdom to its present state. Even one-quarter of this, however, would far exceed the time which physics and astronomy seem able to allow for the completion of the process. Finally, a difficulty exists as to the reason of the ab- sence of rich fossiliferous deposits in the oldest strata — if life was then as abundant and varied as, on the Darwinian theory, it must have been. Mr. Darwin himself admits 1T " the case at present must remain inexplicable ; and may be truly urged as a valid argument against the views" entertained in his book. 17 " Origin of Species," 5th edit., p. 381. VI.] SPECIES AND TIME. 157 Thus, then, we find a wonderful (and, on Darwinian principles, an all but inexplicable) absence of minutely transitional forms. All the most marked groups, bats, pterodactyls, chelonians, ichthyosauria, anoura, etc., appear at once upon the scene. Even the horse, the animal whose pedigree has been probably best preserved, affords no conclusive evidence of specific origin by infinitesimal, fortuitous variations ; while some forms, as the labyrintho- donts and trilobites, which seemed to exhibit gradual change, are shown by further investigation to do nothing of the sort. As regards the time required for evolution (whether estimated by the probably minimum period re- quired for organic change, or for the deposition of strata /-% which accompanied that change), reasons have been sug- --';••' gested why it is likely that the past^ history of the earth ( does not supply us with enough : First, because of the I . prodigious increase in the importance and number of .j*jp differences and modifications which we meet with as we ' L traverse successively greater and more primary zoological - .'/ groups ; and, secondly, because of the vast series of strata *<_ necessarily deposited if the period since the Lower Silurian ~f marks but a small fraction of the period of organic evolution. Finally, the absence or rarity of fossils in the oldest rocks is a point at present inexplicable, and not to be forgotten or neglected. Now all these difficulties are avoided if we admit that ..' ^ j . ../ new forms of animal life of all degrees of complexity ap- pear from time to time with comparative suddenness, be- * , , ,. , • . j ~~P — — &&**»& ing evolved according to laws in part depending on sur- rounding conditions, in part internal — similar to the way in which crystals (and, perhaps from recent researches, the lowest forms of life) build themselves up according to the ^/L^HA / internal laws of their component substance, and in harmony and correspondence with all environing influences and""*^ conditions. 158 THE GENESIS OF SPECIES. CHAP. CHAPTER VII. SPECIES AND SPACE. The Geographical Distribution of Animals presents Difficulties.— These not insur- mountable in themselves; harmonize with other Difficulties.— Fresh-water Fishes.— Forms common to Africa and India; to Africa and South America; to China and Australia; to North America and China; to New Zealand and South America; to South America and Tasmania; to South America and Australia. — Pleurodont Lizards. — Insectivorous Mammals. — Similarity of Euro- pean and Squth American Frogs. — Analogy between European Salmon and Fishes of New Zealand, etc. — An Ancient Antarctic Continent probable.— Other Modes of accounting for Facts of Distribution.— Independent Origin of Closely-similar Forms. — Conclusion. THE study of the distribution of animals over the earth's surface presents us with many facts having certain not unimportant bearings on the question of specific origin. Among these are instances which, at least at first sight, appear to conflict with the Darwinian theory of " Natural Selection." It is not, however, here contended that such facts do by any means constitute by themselves obstacles which cannot be got over. Indeed, it would be difficult to imagine any obstacles of the kind which could not be sur- mounted by an indefinite number of terrestrial modifica- tions of surface — submergences and emergences — junctions and separations of continents in all directions and combina- tions of any desired degree of frequency. All this being supplemented by the intercalation of armies of enemies, multitudes of ancestors of all kinds, and myriads of con- necting forms, whose raison d^etre may be simply their utility or necessity for the support of the theory of " Natu- ral Selection." VII.] SPECIES AND SPACE. 159 Nevertheless, when brought in merely to supplement and accentuate considerations and arguments derived from other sources, in that case difficulties connected with the geographical distribution of animals are not without sig- nificance, and are worthy of mention even though, by them- selves, they constitute but feeble and more or less easily explicable puzzles which could not alone suffice either to sustain or to defeat any theory of specific organization. Many facts as to the present distribution of animal life over the world are very readily explicable by the hypothe- sis of slight elevations and depressions of larger and smaller parts of its surface, but there are others the exist- ence of which it is much more difficult so to explain. The distribution either of animals possessing the power of flight, or of inhabitants of the ocean, is, of course, easily to be accounted for; the difficulty, if there is really any, must mainly be with strictly terrestrial animals of mod- erate or small powers of locomotion and with inhabit- ants of fresh water. Mr. Darwin himself observes,1 " In regard to fish, I believe that the same species never occur in the fresh waters of distant continents." Now, the au- thor is enabled by the labors and through the kindness of Dr. Giinther, to show that this belief cannot be maintained ; he having been so obliging as to call attention to the fol- lowing facts with regard to fish-distribution. These facts show that though only one species which is absolutely and exclusively an inhabitant of fresh water is as yet known to be found in distant continents, yet that in several other instances the same species is found in the fresh water of distant continents, and that very often the same genus is so distributed. The genus Mastacembelus belongs to a family of fresh- water Indian fishes. Eight species of this genus are de- 1 "Origin of Species," 5th edit. 1869, p. 463. 160 THE GENESIS OF SPECIES. [CHAP. scribed by Dr. Gunther in his catalogue.3 These forms ex- tend from Java and Borneo on the one hand, to Aleppo 011 the other. Nevertheless a new species (J£ cryptacanthus) has been described by the same author,3 which is an in- habitant of the Camaroon country of Western Africa. He observes : " The occurrence of Indian forms on the West Coast of Africa, such as Periophthalmus, Psettus, Masta- oembelus, is of the highest interest, and an almost new fact in our knowledge of the geographical distribution of fishes." Ophiocephalus, again, is a truly Indian genus, there being no less than twenty-five species,4 all from the fresh waters of the East Indies. Yet Dr. Gunther informs me that there is a species in the Upper Nile and in West Africa. The acanthopterygian family (Labyrinthici) contains nine fresh-water genera, and these are distributed between the East Indies and South and Central Africa. The Carp fishes (Cypronoids) are found in India, Africa, and Madagascar, but there are none in South America. Thus existing fresh-water fishes point to an immediate connection between Africa and India, harmonizing with what we learn from Miocene mammalian remains. On the other hand, the Characinidce (a family of the physostomous fishes) are found in Africa and South Amer- ica, and not in India, and even its component groups are so distributed, — namely, the Tetragonopterina* and the Hydrocyonina. 6 Again, we have similar phenomena in that almost ex- clusively fresh-water group the Siluroids. 2 See his Catalogue of Acanthopterygian Fishes in the British Mu- seum, vol. iii., p. 540. 3 Proc. Zool. Soc., 1867, p. 102, and Ann. Mag. of Nat. Hist. vol. xx., p. 110. 4 See Catalogue, vol. iii., p. 469. 5 Ibid., vol. v., p. 311. 6 Ibid., p. 345. VII.] SPECIES AND SPACE. 161 Thus the genera Glarias 7 Hetero branchus 8 are found both in Africa and the East Indies. Plotosus is found in Africa, India, and Australia, and the species P. anguillaris 9 has been brought from both China and Moreton Bay. Here, therefore, we have the same species in two distinct geographical regions. It is, however, a coast fish, which, though entering rivers, yet lives in the sea. Eutropius 10 is an African genus, but M obtusirostris comes from India. On the other hand, Amiurus is a North American form; but one species, A. Cantonensis,11 comes from China. The genus Gralaxias ia has at least one species common to New Zealand and South America, and one common to South America and Tasmania. In this genus we thus have an absolutely and completely fresh-water form of the very same species distributed between different and distinct geo- graphical regions. Of the lower fishes, a lamprey, Mordacia mordax™ is common to South Australia and Chili ; while another form of the same family, namely, G-eotria Chilensis™ is found not only in South America and Australia, but in New Zea- land also. These fishes, however, probably pass part of their lives in the sea. We thus certainly have several species which are com- mon to the fresh waters of distant continents, although it cannot be certainly affirmed that they are exclusively and entirely fresh-water fishes throughout all their lives except in the case of Gralaxias. Existing forms point to a close union between South America and Africa on the one hand, and between South America, Australia, Tasmania, and New Zealand, on the other; but these unions were not synchronous any more 7 See Catalogue, vol. iiL, p. 13. » Ibid., p. 21. 9 Ibid., vol. v., p. 24. »o Ibid., p. 62. » Ibid., p. 100. 12 Ibid., vol. vi., 208. 13 Ibid., vol. viii., p. 507. w Ibid., p. 509. 162 THE GENESIS OF SPECIES. [CHAP. than the unions indicated between India and Australia, China and Australia, China and North America, and India and Africa. Pleurodont lizards are such as have the teeth attached by their sides to the inner surface of the jaw, in contradis- tinction to acrodont lizards, which have the bases of their teeth anchylosed to the summit of the margin of the jaw. INNER SIDE OF LOWER JAW OF PLETJRODONT LIZARD. (Showing the teeth attached to the inner surface of its side.) Now pleurodont iguanian lizards abound in the South American region ; but nowhere else, and are not as yet known to inhabit any part of the present Continent of Africa. Yet pleurodont lizards, strange to say, are found in Mada- gascar. This is the more remarkable, inasmuch as we have no evidence yet of the existence in Madagascar of fresh- water fishes common to Africa and South America. Again, that remarkable island Madagascar is the home of very singular and special insectivorous beasts of the genera Centetes, Ericulus, and Echinops; while the only other member of the group to which they belong is Solen- odon, which is a resident in the West Indian Islands, Cuba, and Hayti. The connection, however, between the West Indies and Madagascar must surely have been at a time when the great lemurine group was absent ; for it is diffi- cult to understand the spread of such a form as Solenodon, and at the same time the non-extension of the active le- murs, or their utter extirpation, in such a congenial locality as the West Indian Archipelago. VII.] SPECIES AND SPACE. 163 The close connection of South America and Australia is demonstrated (on the Darwinian theory), not only from the marsupial fauna of both, but also from the frogs and toads which respectively inhabit those regions. A truly remarkable similarity and parallelism exist, however, be- tween certain of the same animals inhabiting Southwest- ern America and Europe. Thus Dr. Giinther has de- scribed 15 a frog from Chili by the name of cacotus, which singularly resembles the European bombinator. £-o"irep K&V et eVe/ca TOU eyfj/ero, ravra /*ej> eVciflrj airb rod avro/J-dTov ffvffr&VTa eirtTTjSeuos, oVa 8e ^] O'SJTWS airdbtero Kal air6\\vTai, Kaddirep 'EjU7re8o/cA.7}s Aeyei TO. /Joyyej//} /cai wSpOTrpwpa." — ARIST. Phys.t ii. c. 8. XII.] THEOLOGY AND EVOLUTION. 307 some that there is and can be absolutely nothing in physi- cal science which forbids them to regard those natural laws as acting with the Divine concurrence and in obedience to a creative fiat originally imposed on the primeval Cosmos, " in the beginning," by its Creator, its Upholder, and its Lord. 6, II^DEX. A. AARD-VAKK, 189. Absolute creation, 269. Acanthometrse, 201. Acrodont teeth, 162. Acts formerly moral, 210. Acts materially moral, 210. Adductor muscles, 92. Agassiz, Prof., 288. Aged, care of, 206. Aggregational theory, 177. Algoa Bay, cat of, 112. Allantois, 95. Amazons, butterflies of, 99. Amazons, cholera in the, 206. American butterflies, 41. American maize, 114. American monkeys, 241. Amiurus, 161. Amphibia, 128. Analogical relations, 171. Ancou sheep, 114, 117, 242. Andrew Murray, Mr., 96. Angora cats, 190. Animal's sufferings, 277. Ankle bones, 172. Annelids undergoing fission, 183, 226. Annulosa, eye of, 90. Anoplotherium, 124. Anteater, 97. Antechinus, 95. Antenna, of orchid, 69. Anthropomorphism, 274. Ape's sexual characters, 61. Apostles' Creed, 260. Appendages of lobster, 175. Appendages of Normandy pigs, 113. Appendages of turkey, 114. Appendix, vermiform, 96. Appreciation of Mr. Darwin, 22. Apteryx, 19, 83. Aqueous humor, 89. Aquinas, St. Thomas, 30, 280, 282. Archegosaurus, 149. Archeopteryx, 86. Arcturus, 207. Argyll, Duke of, 27, 293. Aristotle, 306. Armadillo, extinct kind, 124. Arthritis, rheumatic, 197. Artiodactyle foot, 124. Asa Gray, Dr., 270, 272, 277. Asceticism, 207. Ascidians, placental structure, 93. Assumptions of Mr. Darwin, 28. Astronomical objections, 150. Auditory organ, 86. Augustine, St., 30, 281. Aurelius, Marcus, 221. Avian limb, 121. Avicularia, 93. Axolotl, 179. Aye- Aye, 122. Aylesbury ducks, 249. BACKBONE, 149, 176. Bacon, Koger, 283. Baleen, 54. Bamboo insect, 45. Bandicoot, 80. Bartlett, Mr. A. D., 140, 249. Bartlett, Mr. E., 206. Basil, St., 30. Bastian, Dr. H. Charlton, 129, 234, 253, 283. Bat, wing of, 77. Bates, Mr., 41, 98, 101. Bats, 123. Beaks, 96. Beasts, sufferings of, 260. Beauty of shell-fish, 67. Bee orchid, 68. Bird, wings of, 77. Birds compared with reptiles, 83. BmTs-head processes, 90. Birds of Paradise, 104. Birth of individual and species, 14. Bivalves, 92. Black sheep, 136. Black-shouldered peacock, 114. Bladebone, 83. Blood-vessels, 196. INDEX. 309 Blyth, Mr., 114, 195. Bones of skull, 167. Bonnet, M., 232. Borwick, Mr., 212. "Boots" of pigeons, 195. Breathing, modified power of; 113. Breeding of lions, 249. B rill, 49. B roccoli, variety of, 114. Bryozoa, 93. Buclmer, Dr., 290. Budd, Dr. W., 198. Buffon, 232. Bull-dog's instinct, 276. Burt, Prof. Wilder, 195, 198. Butterflies, 41. Butterflies, Amazonian, 99. Butterflies, American, 41. Butterflies of Indian region, 97. Butterflies, tails of, 99. Butterfly, Leaf, 43. C. CACOTTTS, 163. Caecum, 96. Calamaries, 90. Cambrian deposits, 151. Cape ant-eater, 189. Care of aged, 206. Carinate birds, 83. Carnivora, 81. Carnivorous dentition, 124. Carp fishes, 160. Carpal bones, 120, 194. Carpenter, Dr., 129. Carpus, 192, 193. Cases of conscience, 215. Cassowary, 83. Cataseturn, 69. Causes of spread of Darwinism, 22. Cebus, 241. Celebes, butterflies of, 99. Centetes, 162. Centipede, 79, 173. Cephalopoda, 87. Ceroxylus laceratus, 48. Cetacea, 54, 97, 119, 122, 188. Chances against few individuals, 70. Characinidse, 160. Cheirogaleus, 172. Chetahs, 250. Chickens, mortality of hybrids, 138. Chioglossa, 179. Chiromys, 122. Cholera, 206. Choroid, 89. Chronic rheumatism, 197. Circumcision, 227. Clarias, 161. Climate, effects of, 112. Climbing plants, 122. Clock-thinking illustration, 265. Cobra, 62. Cockle, 92. Cod, 51. Colloidal matter, 283. Conceptions, symbolic, 267. Connecticut footsteps, 145. Connecting links, supposed, 122. Conscience, cases of, 215. Conscientious Papuan, 212. Cope, Prof., 84, 144. Coracoid, of birds and reptiles, 84. Cornea, 90. Cornelius & Lapide, 282. Correlation, laws of, 188. Corti, fibres of, 66, 296. Coryanthes, 68. Costa, M., 102. Cranial segments, 186. Creation, 261, 269 Creator, 27, 268. Creed, Apostles1, 260. Crocodile, 55. Croll, Mr., 151. Crustacea. 93, 174. Cry ptacan thus, 160. Crystalline matter, 283. Crystals of snow, 200. Cuttle-fishes, 87, 88. Curier, 124. Cyprinoids, 160. Cytheridea, 92. DANA, Prof., 163. Darwin, Mr. Charles, 14, 22, 25, 27, 33, 35, 39, 46, 48, 55, 57, 59, 60, 68, 69, 72, 78, 102, 108, 112, 114, 121, 133, 140, 143, 152, 156, 159, 164, 165, 195, 202, 204, 211, 223, 224, 229, 232, 233, 237, 248, 250, 268, 270, 274, 275, 292, 293. Datura tatula, 115. Delhi, days at, 112. Delpino, Signor, 227, 228, 230. Democritus, 232, 293, 306. Density of air for breathing, 113. Dentition, carnivorous, 124. Derivation, 254. Derivative creation, 268, 300. Design, 276. Devotion, 207. Dibranchiata, 88. Difficulties of problem of specific origin, 13. Digits, supernumerary, 137, 194. Digits, turtles, 121. Dimorphodon, 84. Dinornis, 83. Dinosauria, 85. Diseased pelvis, 197. Dissemination of seeds, 78. Doris, 184. Dotheboys Hall, 289. Dragon, the flying, 77, 172. Dragon-fly, 91. Droughts, 37. Duck-billed platypus, 189. Dugong, 54, 190. Duke of Argyll, 27, 293. Dyspepsia, 215. 310 INDEX. EAR, 8T. Ear, formation of, 63. Early specialization, 125. Echinodermata, 56. Echinoidea, 56. Echinops, 162. Echinorhinus, 186. Echinus, 55. Economy, Fuegian political, 206. Eczema, 197. Edentata, 188. Egyptian monuments, 152. Elasmobranchs, 155. Elbow and knee affections, 193. Empedocles, 306. Eocene ungulata, 125. Eolis, 184. Equus, 161. Ericulus, 162. Ethics, 202. Eudes Deslongchamps, 112. Eurypterida, 153, 185. Eutropius, 162. Everett, Eev. R., 112. Evolution requires geometrical increase of time, 153. Eye, 89. Eye, formation of, 64. Eyeoftrilobites, 149. F. FABRE, M., 59. Feather-legged breeds, 196. Feejeeans, 214. Fertilization of orchids, 68. " Fiat justitia, ruat coelum," 209. Fibres of Corti, 66,296. Final misery, 208. Finger of Potto, 119. Fish, flying, 77. Fishes, fresh-water, 159. Fishes, thoracic and jugular, 51, 155. Fixity of position of limbs, 51. Flat-fishes, 49, 180. Flexibility of bodily organization, of, 133. Flexibility of mind, 284. Flies, horned, 107. Flight of spiders, 78. Flounder, 50. Flower, Prof., 178, 248, 300. Fly, orchid, 68. Flying-dragon, 7T, 172. Flying-fish, 77. Foetal teeth of whales, 19. Food, effects on pigs, 113. Footsteps of Connecticut, 145. Foraminifera, 200. Formally moral acts, 210. Formation of eye and ear, 64. Forms, substantial, 200, 290. Four-gilled Oephalopods, 89. Fowls, white silk, 136. French theatrical audience, 213. Fresh-water fishes, 159. Frogs, Chilian and European, 163. Fuego, Terra del, 206. GrALAGO, 172. Galaxias, 161. Galeus vulgaris, 186. Galton, Mr. F., Ill, 127, 244. Gascoyen, Mr., 196. Gavials, 55. Gegenbaur, Prof., 190, 193. Gemmules, 223. Generative system, its sensitiveness, 250. Genesis of morals, 216. Geographical distribution, 158. Geographical distribution explained by Nat- ural Selection, 18. Geometrical increments of time, 153. Geotria, 161. Giraffe, neck of, 36. Gizzard-like stomach, 96. Glacial epoch, 164, Glyptodon, 124. Godron, Dr., 115. Goose, its inflexibility, 133, GOppert, Mr., 115. Gould, Mr., 102. Grasshopper, Great Shielded, 103. Gray, Dr. Asa, 270, 272, 277. Great Ant-eater, 116. Great Salamander, 186. Great Shielded Grasshopper, 103. Greyhounds in Mexico, 118. Greyhounds, time for evolution of, 152. Guinea-fowl, 134. Guinea-pig, 140. Gunther, Dr., 159, 160, 186. H. HAIRLESS DOGS, 188, 190. Hamilton, Sir William, 267. Harmony, musical, 66, 296. Heart in birds and reptiles, 172. Hegel, 232. Heliconidae, 41. Hell, 208. Heptanchus, 186. Herbert Spencer, Mr., 33, 40, 80, 86, 117, 180, 182, 184, 186, 199, 203, 216, 217, 219, 233, 243, 261, 262, 264, 267. Hessian flies, 184. Heterobranchus, 160. Hewitt, Mr., 138, 195. Hexanchus, 186. Hipparion, 111, 148. Homogeny, 172. Homology, bilateral or lateral, 170, 178. Homology, meaning of term, 19, 170. Homology, serial, 173. Homology, vertical, 179. Homoplasy, 173. Honey-auckers, 104. INDEX. 311 Hood of cobra, 62. Hook-billed ducks, 114. Hooker, Dr., 164. Horned flies, 10T. Horny plates, 53, 54. Horny stomach, 96. Human larynx, 67, 296. Humphry, Prof., 177. Hutton, Mr. E. Holt, 216, 21.. Huxley, Prof., 80, 82, 84, 85, 108, 117, 123, 144, 145, 151, 155, 177, 186, 187, 246, 263. Hybrids, mortality of, 138. Hydrocyonina, 160. Hyperphysical action, 269. Hyrax, 193. I. ICHTHYOPBIDA, 123. Ichthyosaurus, 92, 120, 146, 191. Ichthyosis, 198. Iguanodon, 84. Illegitimate symbolic conceptions, 267. Illustration by clock-thinking, 265. Imaginal disks, 58, 184. Implacental mammals, 81, 82. Independent origins, 167. Indian butterfly, 43. Indian region's butterflies, 96. Indians and cholera, 206. Individual, meaning of word, 14. Infirm, care of; 206. Influence, local, 96. Insect, walking-leaf, 48. Insects, walking-stick and bamboo, 45. Insectivora, 81. Insectivorous mammals, 162. Insectivorous teeth, 81. Instinct of bull-dog, 276. Intermediate forms, 142. Intuitions, primary, 267. Irregularities in blood-vessels, 196. Isaria felina, 130. JAPANNED PEACOCK, 114. Jews, 227. Joints of backbone, 171, 176. Jugular fishes, 51, 155. Julia Pastrana, 188. KALLIMA INACHIS, 44. Kallima paralekta, 44. Kangaroo, 54, 80. Kowalewsky, 95. Knee and elbow affections, 197. Kolliker, Prof., 118. LABTBINTHTCI, 160. Labyrinthodon, 118, 138. Lamarck, 15. Lankester, Mr. Eay, 167, 172. Larynx of kangaroo, 55. Larynx of man, 67, 296. Lateral homology, 178. Laws of correlation, 188. Leaf butterfly, 43. Legitimate symbolic conceptions, 267. Lens, 90. Lepidosteus, 186. Lepra, 197. Lewes, Mr. G. H., 108, 227, 229, 232. Louis, St., 221. Louis XV., 220. Louis XVI., 220. Limb genesis, 190. Limb muscles, 194. Limbs, fixity of position of, 51. Limbs of lobster, 175. Links, supposed connecting, 122. Lions, breeding, 249. Lions, diseased pelvis, 196. Llama, 123. Local influences, 97. Lobster, 174. Long-tailed bird of Paradise, 105. Lubbock, Sir John, 212, 219. Lyell, Sir Charles, on dogs, 113, 120. M. MACHAIKODTJS, 124. Macrauchenia, 124. Macropodidse, 82. Macroscelides, 82. Madagascar, 162, 166. Magnificent bird of Paradise, 106. Maize, American, 114. Mammals, 80. Mammary gland of kangaroo, 54. Mammary gland, origin of, 60. Man, origin of, 277. Man reveals God, 267. Man, voice of, 66. Manatee, 54, 190. Manchamp breed of sheep, 114. Manis, 189. Man's larynx, 67. Many simultaneous modifications, 69. Marcus Aurelius, 221. Martineau, Mr. James, 214, 261. Mastacembelus, 159. Materially moral acts, 210. Matter, crystalline and colloidal, 283. Meaning of word " individual," 14. Meaning of word "species," 14. Mechanical theory of spine, 178. Mediterranean oyster, 102, 112. Meehan, Mr., 102. Mexico, dogs in, 113. Mill, John Stuart, 28, 203, 207, 209. Mimicry, 20, 41. Miracle, 305. Molars, 124. Mole, 190. Moliere, 245. Mombas, cats at, 112. 312 INDEX. Monkeys, American, 241. Monster proboscis, 137. Moral acts, 210. Mordacia, 161. Murphy, Mr. J. J., 64, 66, 90, 117, 128, 129, 151, 200, 236, 294, 299. Murray, Mr. Andrew, 96. Mus delicatulus, 96. Muscles of limbs, 194. Mussel, 92. Myrmecophaga, 96. N. NASALIS. SEMNOPiTHECtrs, 153. Nathusius, 113. Natural Selection, shortly stated, 17. Naudin, M. C., 115. Nautilus, 89. Nebular evolution, 291. Neck of giraffe, 36. Newman, the Eev. Dr., 271, 285, 287, 304. New Zealand Crustacea, 164. New Zealand fishes, 161. Niata, cattle, 114. Nile fishes, 160. Normandy pig, 113. North American fish, 161. Nycticebus, 193. O. OBJECT of book, 17. Objections from astronomy, 150. Octopods, 90. Offensive remarks of Prof. Vogt, 25. Old, care of the, 206. Old Fuegian women, 206. Omygena, exigua, 129. Ophiocephalus, 160. Optic lobes of pterodactyls, 84. Orchids, 106. Orchids, Bee, etc., 68. Organ of hearing, 86. Organ of sight, 89. Organic polarities, 200. Origin of man, 294. Orioles, 104. Ornithoptera, 97. . Ornithorhynchus, 189. Orthoceratidse, 184, Orycteropus, 189. Ostracods, 92. Ostrich, 83. Otoliths, 87. Outlines of butterflies' wings, 100. Owen, Prof., 88, 116, 137, 233, 254, 291. Oyster of Mediterranean, 102, 112. Oysters, 92. P. PAGET, Mr. J., 197. Pateotherium, 124. Pallas, 140. Pangenesis, 31, 223. Pangolin, 190. Papilio Hospiton, 99. Papilio Machaon, 99. Papilio Ulysses, 98. Papilionid*, 97. Papuan morals, 212. Parthenogenesis, 233. Passiflora gracilis, 121. Pastrana, Julia, 188. Pathological polarities, 199. Pavo nigripennis 114. Peacock, black-shouldered, 114. Peacock inflexibility of, 133, Pedicellarite, 57. PeMs, diseased, 197. Pendulous appendages of turkey, 114i Perameles, 81. Periophthalmus, 160. Perissodactyl ungulates, 124. Permian, jugular fish, 155. Perodicticus, 119, 193. Phalangers, 80. Phasmidse, 103. PhyUopods, 93. Physical actions, 269. " Physiological units," 182, 234 Pigeons' " boots," 195. Placental mammals, 81. Placental reproduction, 95. Plants, tendrils of, 121. Plates of baleen, 53. Platypus, 189. Pleiades, 207. Plesiosaurus, 120, 147, 192. Pleurodont dentition, 162. Pleuronectidae, 49, 180. Plotosus, 161. Poisoning apparatus, 69. Poisonous serpents, 62. Polarities, organic, 199, 200. Political economy, Fuegiau, 206. Polyzoa, 93, 94. Pompadour, Madame de, 220. Poppy, variety of, 115. Porcupine, 190. Porto Santo rabbit, 114, 136. Potto, 119, 193. Pouched beasts, 80. Powell, the Rev. Baden, 276, 278, 303. Premolars, 124. Prepotency, 138. Primary intuitions, 267. Primitive man, 218. Problem of origin of kinds, 18. Proboscis monkey, 153. Proboscis of ungulates, 137. Processes, birdVhead, 93. Psettus, 160. Psoriasis, 197. Pterodactyls, compared with birds, 83. Pterodactyls, wing of, 77. Puccinia, 129. Purpose, 275. a. QXTASI-YEBTEBRAL theory of skuU, 186. INDEX. 313 R. BABBIT of Porto Santo, 114, 136. Eadial ossicle, 190. Karefied air, effect on dogs, 113. Eattlesnake, 61. Eed bird of Paradise, 106. Relations, analogical, 171. Eolations, homological, 170. Eeptiles compared with birds, 83. Eetina, 89. Eetrieving, virtue a kind of, 203, 219. Eeversion, cases of, 137. Eibs of Cetacea and Sirenia, 54. Eibs of flying-dragon, 77, 172. Eichardson's figures of pigs, 113. Eoger Bacon, 283. Eudimentary structures, 19, 116. SABRE-TOOTHED tiger, 124. St. Augustine, 30, 281, 282. St. Basil 30. St. Hilaire, M., 194. St. Thomas Aquinas, 30, 280, 282. Salamander, great, 186. Salter, Mr., 138. Salvia offlcinalis, 228. Balvia verticillata, 228. Scapula of birds and reptiles, 84. Schreber, 26. Sclerotic, 89. Scorpion, sting of, 79. Seals, 96. Sea-squirts, 95. Seeds, dissemination of, 79. Seely, Mr., on pterodactyls, 84. Segmentation of skull, 187. Segmentation of spine, 186. Segments, similar, 174. Self-existence, 268. Semnopithecus, 153. Sense, organ of, &4, 82, 88, 89. Sensitiveness of generative system, 250. Sepia, 90. Serpents, poisonous, 62. Sexual characters of apes, 61. Sexual selection, 60. Sharks, 96. Shell-fish, beauty of, 67. Shells of oysters, 102, 112. Shielded grasshopper, 102. Silurian strata, 154, 156. Simultaneous modifications, 69. Sirenia, 54. Sir John Lubbock, 212, 219. Sir William Thomson, 150. Sitaris, 59. Six-shafted bird of Paradise, 104. Skull bones, 167. Skull segments, 187. Sloth, windpipe of, 95. 14 Smithfield, wife-selling in, 213. Snow, crystals of, 200. Sole, 49. Solenodon, 162. Species, meaning of word, 14 Spelerpes, 179. Spencer, see Herbert Spencer. Spider orchid, 68. Spiders, flight of, 78. Spine of Glyptodon, 124. Spine, segmentation of, 186. Squalid*, 50. Squilla, 174. Sterility of hybrids, 139. Stings, 79. Straining action of baleen, 54. Struthious birds, 83, 165. Sturgeon, 186. Suarez, 31, 281. Substantial forms, 201, 290. Sufferings of beasts, 277. Supernatural action, 269. Supernatural action not to be looked for in Nature, 28. Supernumerary digits, 137, 196. Sylis, 183, 226. Symbolic conceptions, 267. Symmetrical diseases, 197. Syphilitic deposits, 197. T. TADPOLE^ beak, 96. Tails of butterflies, 99. Tapir, 137, 148. Tarsal.bones, 173, 212. Teeth of Cetacea, 96. Teeth of insectivora, 81. Teeth of kangaroo and Macroscelides, 82. Teeth of seals, 96. Teeth of sharks, 96. Teleology and evolution compatible, 291. Tendrils of climbing plants, 121. Tenia echinococcus, 184. Teratology, 187. Tetragonopterina, 160. Thomson, Sir William, 150. Thoracic fishes, 51. Thorax of crustaceans, 93. Thylacine, 80. Tierra del Fuego, 206. Tiger, sabre-toothed, 124. Time required for evolution, 142. Tope, 186. Trabeculse cranii, 186. Transitional forms, 142. Transmutationism, 257. Trevelyan, Sir J. Peacock, 114. Trilobites, 149, 155, 185. Tunicaries, 95. Turbot, 49. Turkey, effects of climate on, 114. Turkish dog, 57. Two-gilled cephalopoda, 89. ' Type, conformity to, 257. 314 INDEX. U. UMBILICAL vesicle, 95. Ungulate, 37, 123. Ungulata eocene, 124. Units, physiological, 182, 234. Unknowable, the, 261. Upper Silurian strata, 154, 156. Urotrichus, 81. V. VARIABILITY, different degrees of, 133. Vermiform appendix, 96. Vertebra of skull, 186. Vertebral column, 176, 185. Vertebrate limbs, 50, 177. ' Vertical homology, 179. Vesicle, umbilical, 95. "Vestiges of Creation," 15. View here advocated, 17. Vitreous humor, 89. Vogt, Prof., 25, 290. Voice of man, 67. Voltaire, 245. Wallace, Mr. Alfred, 14, 22, 38, 41, 42, 43, 48, 67, 97, 98, 100, 103, 117, 131, 205, 212, 241, 292, 297, 302. Weaver fishes, 51. Weitbrecht, 195. Whale, foetal teeth of, 19. Whale, mouth of; 53. Whalebone, 53. Whales, 92. White silk fowls, 136. Wife-selling, 213. Wild animals, their variability, 135. Wilder, Prof. Burt, 195, 198. Windpipe, 95. Wings of bats, birds, and pterodactyls, 77, Wing's of birds, origin of, 120. Wings of butterflies, outline of, 100. Wings of flying-dragon, 77, 172. Wings of humming-bird, 171. Wings of humming-bird hawk moth, 171. Wings of insects, 78. Wombat, 96. Women, old Fuegian, 206. Worms undergoing fission, 184, 226. Wyman, Dr. Jeffries, 199. WAGNER, J. A., 26. Wagner, Nicholas, 184. Walking leaf, 48. Walking-stick insect, 45. YORK MINSTER, a Fuegian, 211. Z. ZEBRAS, 148. Zoological Gardens, Superintendent o£ 140. THE ENI>. WOKKS OF HEEBEET SPENCEE, PUBLISHED BY D. 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Price, $2.50 III.— SOCIAL STATICS: OR THE CONDITIONS ESSENTIAL TO HUMAN HAPPINESS SPECIFIED, AND THE FIRST OF THEM DEVELOPED. 623 pages. Price, IV.— EDUCATION : INTELLECTUAL, MORAL, AND PHYSICAL. 283 pages. Price, $1.25 V.— CLASSIFICATION OF THE SCIENCES. 60 pages. Price, ... ..... $0.25 VI.— SPONTANEOUS GENERATION, &c. 16 pages. Price, . ... $0.25 n THE ORIGIN OF CIVILIZATION; OR, THE PRIMITIVE CONDITION OF MAN. By SIR JOHN LTJBBOCK, Bart, M, P., F. B, S. 38O IPages. Illustrated.. This interesting work is the fruit of many years' research by an accomplished naturalist, and one well trained in mod- ern scientific methods, into the mental, moral, and social con- dition of the lowest savage races. The want of a work of this kind had long been felt, and, as scientific methods are being more and more applied to questions of humanity, there has been increasing need of a careful and authentic work de- scribing the conditions of those tribes of men who are lowest in the scale of development. " This interesting work — for it is intensely so in its aim, scope, and the ability of its author — treats of what the scientists denominate anthropology^ or the natural history of the human species ; the complete science of man, body and soul, including sex, temperament, race, civilization, etc." — Provi- dence Press. " A work which is most comprehensive in its aim, and most admirable in its execution. The patience and judgment bestowed on the book are every- where apparent ; the mere list of authorities quoted giving evidence of wide and impartial reading. The work, indeed, is not only a valuable one on ac- count of the opinions it expresses, but it is also most serviceable as a book of reference. It offers an able and exhaustive table of a vast array of facts, which no single student could well obtain for himself, and it has not been made the vehicle for any special pleading on the part of the author."— London Athenaeum. " The book is no cursory and superficial review; it goes to the very heart of the subject, and embodies the results of all the later investigations. It is replete with curious and quaint information presented in a compact, luminous, and entertaining form." — Albany Evening Journal. " The treatment of the subject is eminently practical, dealing more with fact than theory, or perhaps it will be more just to say, dealing only with theory amply sustained by fact." — Detroit Free Press. "This interesting and valuable volume illustrates, to some extent, the way in which the modern scientific spirit manages to extract a considerable treasure from the chaff and refuse neglected or thrown aside by former in- quirers."— London Saturday Review. D. APPLETON & CO, Publishers. SPENCERS SYSTEM OF PHILOSOPHY. THE PHILOSOPHY OF EVOLUTION, By HERBERT SPENCER. This great system of scientific thought, the most original and important men- tal undertaking of the age, to which Mr. Spencer has devoted his life, is now well advanced, the published volumes being: First Principles, The Principles of Bi- ology, two volumes, and The Principles of Psychology, vol. i., which will bo shortly printed. This philosophical system differs from all its predecessors in being solidly based on the sciences of observation and induction ; in representing the order and course of Nature ; in bringing Nature and man, life, mind, and society, under one great law of action ; and in developing a method of thought which may serve for practical guidance in dealing with the affairs of life. That Mr. Spencer is the man for this great work will be evident from the following statements: " The only complete and systematic statement of the doctrine of Evolution with which I am acquainted is that contained in Mr. Herbert Spencer's ' System of Philosophy ; ' a work which should be carefully studied by all who desire to know whither scientific thought is tending."— T. H. HUXLEY. " Of all our thinkers, he is the one who has formed to himself the largest new scheme of a systematic philosophy." — Prof. MASSON. " If any individual influence is visibly encroaching on Mills in this country, it is his."— Ibid. "Mr. Spencer is one of the most vigorous as well as boldest '.tinkers that English speculation has yet produced."— JOHN STUART MILL. " One of the acutest metaphysicians of modern times."— Ibid. " One of our deepest thinkers."— Dr. JOSEPH D. HOOKEB. It is questionable if any thinker of finer calibre has appearo'l hi our coun- try."—GEORGE HENRY LEWES. "He alone, of all British thinkers, has organized a philosophy.'1— fl>id. "He is as keen an analyst as is known in the history of philouo^hy ; I do not except either Aristotle or Kant." — GEORGE RIPLEY. " If we were to give our own judgment, we should say that, since Newton, there has not in England been a philosopher of more remarkable speculative and systematizing talent than (in spite of some errors and some narrowness) Mr. Her- bert Spencer." — London Saturday Review. " We cannot refrain from offering our tribute of respect to one who, whether for the extent of his positive knowledge, or for the profundity of his speculative insight, has already achieved a name second to none in the whole rang*, of Eng- lish philosophy, and whose works will worthily sustain the credit of English thought in the present generation."— Westminster Seview. D. Appleton & Company's Publications. LAY SEEMO^S, ADDEESSES, AJSTD KEYIEWS, BY THOMAS HENRY HUXLEY. Cloth, 12mo. 390 pages. Price, $1.75 THIS is the latest and most popular of the works of this in- trepid and accomplished English thinker. The American edition of the work is the latest, and contains, in addition to the English edition, Professor Huxley's recent masterly address on " Spon- taneous Generation," delivered before the British Association for the Advancement of Science, of which he was president. The following is from an able article in the Independent : The " Lay Sermons, Addresses, and Reviews " is a book to be read by every one who would keep up with the advance of truth — as well by those who are hostile as those who are friendly to his conclusions. In it, scientific and philosophical topics are handled with consummate abil- ity. It is remarkable for purity of style and power of expression. No- where, in any modern work, is the advancement of the pursuit of that natural knowledge, which is of vital importance to bodily and mental well-being, so ably handled. Professor Huxley is undoubtedly the representative scientific man of the age. His reverence for the right and devotion to truth have estab- lished his leadership of modern scientific thought. He leads the beliefs and aspirations of the increasingly powerful body of the younger men of science. His ability for research is marvellous. There is possible no more equipoise of judgment than that to which he brings the phenomena of Nature. Besides, he is not a mere scientist. His is a popularized phi. losophy ; social questions have been treated by his pen in a manner most masterly. In his popular addresses, embracing the widest range of top- ics, he treads on ground with which he seems thoroughly familiar. There are those who hold the name of Professor Huxley as synony- mous with irreverence and atheism. Plato's was so held, and Galileo's, and Descartes's, and Newton's, and Faraday's. There can be no greater mistake. No man has greater reverence for the Bible than Huxley. No one more acquaintance with the text of Scripture. He believes there is definite government of the universe ; that pleasures and pains are distrib- uted in accordance with law ; and that the certain proportion of evil woven up in the life even of worms will help the man who thinks to bear his own share with courage. In the estimate of Professor Huxley's future influence upon science, his youth and health form a large element. He has just passed his forty, fifth year. If God spare his life, truth can hardly fall to be the gainer from a mind that is stored with knowledge of the laws of the Creator's operations, and that has learned to love all beauty and haU- *li rileness of Nature and art. THE ORIGIN OF SPECIES, By CHARLES DARWIN. A new American edition of " The Origin of Species," later than the latest English edition, has just been published, with the author's most recent COP- rections and additions. In the whole history of the progress of knowledge there is no case so re- markable of a system of doctrines, at first generally condemned as false and absurd, coming into general acceptance in the scientific world in a single decade From the following statements, the reader will infer the estimate that is now placed upon the man and his works by the highest authorities. " Personally and practically exercised in zoology, in minute anatomy, in geology ; a student of geographical distribution, not on maps and in museums only, but by long voyages and laborious collection ; having largely advanced each of these branches of science, and having spent many years in gathering and sifting materials for his present work, the store of accurately-registered facts upon which the author of the ' Origin of Species' is able to draw at will is prodigious." — Prof. T. H. HUXLEY. " Far abler men than myself may confess that they have not that untiring patience in accumulating, and that wonderful skill in using, large masses of facts of the most varied kind — that wide and accurate physiological knowl- edge— that acuteness in devising, that skill in carrying out experiments, and that admirable style of composition, at once clear, persuasive, and judicial, qualities which, in their harmonious combination, mark out Mr. Darwin as the man, perhaps of all men now living, best fitted for the great work he has undertaken and accomplished." — ALFRED RUSSELL WALLACE. In Germany these views are rapidly extending. Prof. GIEKIE, a distin- guished British geologist, attended the recent Congress of German Natural- ists and Physicians, at Innspruck, in which some eight hundred savants were present, and thus writes: "What specially struck me was the universal sway which the writings of Darwin now exercise over the German mind. You see it on every side, in private conversation, in printed papers, in all the many sections into which such a meeting as that at Innspruck divides. Darwin's name is often men- tioned, and always with the profoundest veneration. But even where no al- lusion is specially made to him, nay, even more markedly, where such allusion is absent, we see how thoroughly his doctrines have permeated the scientific mind, even in those departments of knowledge which might seem at first sight to be farthest from natural history. * You are still discussing in Eng- land,' said a German friend to me, ' whether or not the theory of Darwin can be true. We have got a long way beyond that here. His theory is now our common starting-point.' And, so far as my experience went, I found it to be so." CO. Wwks of Herbert Spencer published by D. .dppieton & Cfc. A NEW SYSTEM OF PHILOSOPHY. FIRST PRINCIPLES. *. VoL Large 12mo. 515 Pages. Price $2 50. CONTENTS : PART FIRST. — TJie Unknowable. ouaptei i. Religion and Science; II. Ultimate Religious ideas; III Ultimate Scientific Ideas ; IV. The Relativity of all Knowledge ; V Th# Reconciliation. PART SECOND. — Laws of the Knowable. I. Laws in General; EL The Law of Evolution; III. The same con- tinued ; IV. The Causes of Evolution ; V. Space, Time, Matter, Motion, and Force ; VI. The Indestructibility of Matter ; VII. The Continuity of Motion ; VIII. The Persistence of Force; IX. The Correlation and Equivalence of Forces; X. The Direction of Motion ; XI. The Rhythm of Motion ; XII. The Conditions Essential to Evolution ; XIII. The Instability of the homoge- neous ; XIV. The Multiplication of Effects ; XV. Differentiation *.nd Inte- gration ; XVI. Equilibration ; XVII. Summary and Conclusion. In the first part of this work Mr. Spencer defines the province, limits, and relations of religion and science, and determines the legitimate scope of philosophy. In part second he unfolds those fundamental principles which have been arrived at within the sphere of the knowable ; which are true of all orders of phenonema, and thus constitute the foundation of all philosophy. The law of Evolution, Mr. Spencer maintains to be universal, and he has here worked it out as the basis of his system. These First Principles are the foundation of a system of Philosophy bolder, more elaborate, and comprehensive perhaps, than any other which nat been hitherto designed in England. — British Quarterly Review. A work lofty in aim and remarkable in execution. — Cornhill Mayazint. In the works of Herbert Spencer we have the rudiments of a positive Theology, and an immense step toward the perfection of the science of Psy- chology.— Christian Examiner. If we mistake not, in spite of the very negative character of his owr. re- mits, be has foreshadowed some strong arguments for the doctrine of a poss- tre Christian Theology. — New Englander. As far as the frontiers of knowledge, where the Intellect may go, there tt BO living man whose guidance may more safely be trusted. — Works of Herbert Spencer published by D. Appleton & Co. ILLUSTRATIONS OF UNIVERSAL PROGRESS. A SERIES OF DISCUSSIONS. 1 Vol Large 12mo. 470 Pa«ea. Price $2.50. CONTENTS : American Notice of Spencer's New System of Philosophy. I, Progress : its Law and Cause. D. Manners and Fashion. HI. The Genesis of Science. IV. The Physiology of Laughter. V. The Origin and Function of Music. VL The Nebular Hypothesis. VIL Bain on the Emotions and the Will Fin. Illogical Geology. IX. The Development Hypothesis. X. The Social Organism. XI. Use and Beauty. XIL The Sources of Architectural Types. XIII. The Ose of Anthropomorphism. These Essays constitute a body of massive and original thought upon a large variety of important topics, and will be read with pleasure by all wlio appreciate a bold and powerful treatment of fundamental themes. Th« general thought which pervades this book is beyond doubt the most impor* tant that the human mind has yet reached. — N. Y. Independent. Those who have read the work on Education, will remember the ana- lytic tendency of the author's mind — his clear perception and admirable ex- position of nrst principles — his wide grasp of facts — his lucid and vigorous style, and the constant and controlling bearing of the discussion on practical results. These traits characterize all Mr. Spencer's writings, and mark, in aii eminent degree, the present volume. — N. Y. Tribune. We regard the distinguishing feature of this work to be the peculiarly Interesting character of its matter to the general reader. This is a great literary as welt as philosophic triumph. In the evolution of a system of Philosophy which demands serious attention, and a keen exercise of the in- tellect to fathom and appreciate, he has mingled much that is really popular »nd entertaining. — Rochester Democrat. Workt of Herbert Spencer punished by D. Afsp