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ABORTIVE OR RUDIMENTARY ORGANS

The abortive organs of naturalists


Parts of structure are said to be “abortive,” or when in a still lower state of development “rudimentary{486},” when the same reasoning power, which convinces us that in some cases similar parts are beautifully adapted to certain ends, declares that in others they are absolutely useless. Thus the rhinoceros, the whale{487}, etc., have, when young, small but properly formed teeth, which never protrude from the jaws; certain bones, and even the entire extremities are represented by mere little cylinders or points of bone, often soldered to other bones: many beetles have exceedingly minute but regularly formed wings lying under their wing-cases{488}, which latter are united never to be opened: many plants have, instead of stamens, mere filaments or little knobs; petals are reduced to scales, and whole flowers to buds, which (as in the feather hyacinth) never expand. Similar instances are almost innumerable, and are justly considered wonderful: probably not one organic being exists in which some part does not bear the stamp of inutility; for what can be clearer{489}, as far as our reasoning powers {232} can reach, than that teeth are for eating, extremities for locomotion, wings for flight, stamens and the entire flower for reproduction; yet for these clear ends the parts in question are manifestly unfit. Abortive organs are often said to be mere representatives (a metaphorical expression) of similar parts in other organic beings; but in some cases they are more than representatives, for they seem to be the actual organ not fully grown or developed; thus the existence of mammæ in the male vertebrata is one of the oftenest adduced cases of abortion; but we know that these organs in man (and in the bull) have performed their proper function and secreted milk: the cow has normally four mammæ and two abortive ones, but these latter in some instances are largely developed and even (??) give milk{490}. Again in flowers, the representatives of stamens and pistils can be traced to be really these parts not developed; Kölreuter has shown by crossing a diæcious plant (a Cucubalus) having a rudimentary pistil{491} with another species having this organ perfect, that in the hybrid offspring the rudimentary part is more developed, though still remaining abortive; now this shows how intimately related in nature the mere rudiment and the fully developed pistil must be.

Abortive organs, which must be considered as useless as far as their ordinary and normal purpose is concerned, are sometimes adapted to other ends{492}: thus the marsupial bones, which properly serve to support the young in the mother’s pouch, are present in the male and serve as the fulcrum for muscles connected only with male functions: in the {233} male of the marigold flower the pistil is abortive for its proper end of being impregnated, but serves to sweep the pollen out of the anthers{493} ready to be borne by insects to the perfect pistils in the other florets. It is likely in many cases, yet unknown to us, that abortive organs perform some useful function; but in other cases, for instance in that of teeth embedded in the solid jaw-bone, or of mere knobs, the rudiments of stamens and pistils, the boldest imagination will hardly venture to ascribe to them any function. Abortive parts, even when wholly useless to the individual species, are of great signification in the system of nature; for they are often found to be of very high importance in a natural classification{494}; thus the presence and position of entire abortive flowers, in the grasses, cannot be overlooked in attempting to arrange them according to their true affinities. This corroborates a statement in a previous chapter, viz. that the physiological importance of a part is no index of its importance in classification. Finally, abortive organs often are only developed, proportionally with other parts, in the embryonic or young state of each species{495}; this again, especially considering the classificatory importance of abortive organs, is evidently part of the law (stated in the last chapter) that the higher affinities of organisms are often best seen in the stages towards maturity, through which the embryo passes. On the ordinary view of individual creations, I think that scarcely any class of facts in natural history are more wonderful or less capable of receiving explanation.

{234}
The abortive organs of physiologists.

Physiologists and medical men apply the term “abortive” in a somewhat different sense from naturalists; and their application is probably the primary one; namely, to parts, which from accident or disease before birth are not developed or do not grow{496}: thus, when a young animal is born with a little stump in the place of a finger or of the whole extremity, or with a little button instead of a head, or with a mere bead of bony matter instead of a tooth, or with a stump instead of a tail, these parts are said to be aborted. Naturalists on the other hand, as we have seen, apply this term to parts not stunted during the growth of the embryo, but which are as regularly produced in successive generations as any other most essential parts of the structure of the individual: naturalists, therefore, use this term in a metaphorical sense. These two classes of facts, however, blend into each other{497}; by parts accidentally aborted, during the embryonic life of one individual, becoming hereditary in the succeeding generations: thus a cat or dog, born with a stump instead of a tail, tends to transmit stumps to their offspring; and so it is with stumps representing the extremities; and so again with flowers, with defective and rudimentary parts, which are annually produced in new flower-buds and even in successive seedlings. The strong hereditary tendency to reproduce every either congenital or slowly acquired structure, whether useful or injurious to the individual, has been shown in the first part; so that we need feel no surprise at these truly abortive {235} parts becoming hereditary. A curious instance of the force of hereditariness is sometimes seen in two little loose hanging horns, quite useless as far as the function of a horn is concerned, which are produced in hornless races of our domestic cattle{498}. Now I believe no real distinction can be drawn between a stump representing a tail or a horn or the extremities; or a short shrivelled stamen without any pollen; or a dimple in a petal representing a nectary, when such rudiments are regularly reproduced in a race or family, and the true abortive organs of naturalists. And if we had reason to believe (which I think we have not) that all abortive organs had been at some period suddenly produced during the embryonic life of an individual, and afterwards become inherited, we should at once have a simple explanation of the origin of abortive and rudimentary organs{499}. In the same manner as during changes of pronunciation certain letters in a word may become useless{500} in pronouncing it, but yet may aid us in searching for its derivation, so we can see that rudimentary organs, no longer useful to the individual, may be of high importance in ascertaining its descent, that is, its true classification in the natural system.
Abortion from gradual disuse.

There seems to be some probability that continued disuse of any part or organ, and the selection of individuals with such parts slightly less developed, would in the course of ages produce in {236} organic beings under domesticity races with such parts abortive. We have every reason to believe that every part and organ in an individual becomes fully developed only with exercise of its functions; that it becomes developed in a somewhat lesser degree with less exercise; and if forcibly precluded from all action, such part will often become atrophied. Every peculiarity, let it be remembered, tends, especially where both parents have it, to be inherited. The less power of flight in the common duck compared with the wild, must be partly attributed to disuse{501} during successive generations, and as the wing is properly adapted to flight, we must consider our domestic duck in the first stage towards the state of the Apteryx, in which the wings are so curiously abortive. Some naturalists have attributed (and possibly with truth) the falling ears so characteristic of most domestic dogs, some rabbits, oxen, cats, goats, horses, &c., &c., as the effects of the lesser use of the muscles of these flexible parts during successive generations of inactive life; and muscles, which cannot perform their functions, must be considered verging towards abortion. In flowers, again, we see the gradual abortion during successive seedlings (though this is more properly a conversion) of stamens into imperfect petals, and finally into perfect petals. When the eye is blinded in early life the optic nerve sometimes becomes atrophied; may we not believe that where this organ, as is the case with the subterranean mole-like Tuco-tuco «Ctenomys»{502}, is frequently impaired and lost, that in the course of generations the whole organ might become abortive, as it normally is in some burrowing quadrupeds having nearly similar habits with the Tuco-tuco?

{237} In as far then as it is admitted as probable that the effects of disuse (together with occasional true and sudden abortions during the embryonic period) would cause a part to be less developed, and finally to become abortive and useless; then during the infinitely numerous changes of habits in the many descendants from a common stock, we might fairly have expected that cases of organs becom«ing» abortive would have been numerous. The preservation of the stump of the tail, as usually happens when an animal is born tailless, we can only explain by the strength of the hereditary principle and by the period in embryo when affected{503}: but on the theory of disuse gradually obliterating a part, we can see, according to the principles explained in the last chapter (viz. of hereditariness at corresponding periods of life{504}, together with the use and disuse of the part in question not being brought into play in early or embryonic life), that organs or parts would tend not to be utterly obliterated, but to be reduced to that state in which they existed in early embryonic life. Owen often speaks of a part in a full-grown animal being in an “embryonic condition.” Moreover we can thus see why abortive organs are most developed at an early period of life. Again, by gradual selection, we can see how an organ rendered abortive in its primary use might be converted to other purposes; a duck’s wing might come to serve for a fin, as does that of the penguin; an abortive bone might come to serve, by the slow increment and change of place in the muscular fibres, as a fulcrum for a new series of muscles; the pistil{505} of the marigold might become abortive as a reproductive part, but be continued in its function of sweeping the pollen out of the anthers; for if in {238} this latter respect the abortion had not been checked by selection, the species must have become extinct from the pollen remaining enclosed in the capsules of the anthers.

Finally then I must repeat that these wonderful facts of organs formed with traces of exquisite care, but now either absolutely useless or adapted to ends wholly different from their ordinary end, being present and forming part of the structure of almost every inhabitant of this world, both in long-past and present times—being best developed and often only discoverable at a very early embryonic period, and being full of signification in arranging the long series of organic beings in a natural system—these wonderful facts not only receive a simple explanation on the theory of long-continued selection of many species from a few common parent-stocks, but necessarily follow from this theory. If this theory be rejected, these facts remain quite inexplicable; without indeed we rank as an explanation such loose metaphors as that of De Candolle’s{506}, in which the kingdom of nature is compared to a well-covered table, and the abortive organs are considered as put in for the sake of symmetry!

RECAPITULATION AND CONCLUSION

I will now recapitulate the course of this work, more fully with respect to the former parts, and briefly «as to» the latter. In the first chapter we have seen that most, if not all, organic beings, when taken by man out of their natural condition, and bred during several generations, vary; that is variation is partly due to the direct effect of the new external influences, and partly to the indirect effect on the reproductive system rendering the organization of the offspring in some degree plastic. Of the variations thus produced, man when uncivilised naturally preserves the life, and therefore unintentionally breeds from those individuals most useful to him in his different states: when even semi-civilised, he intentionally separates and breeds from such individuals. Every part of the structure seems occasionally to vary in a very slight degree, and the extent to which all kinds of peculiarities in mind and body, when congenital and when slowly acquired either from external influences, from exercise, or from disuse «are inherited», is truly wonderful. When several breeds are once formed, then crossing is the most fertile source of new breeds{507}. Variation {240} must be ruled, of course, by the health of the new race, by the tendency to return to the ancestral forms, and by unknown laws determining the proportional increase and symmetry of the body. The amount of variation, which has been effected under domestication, is quite unknown in the majority of domestic beings. In the second chapter it was shown that wild organisms undoubtedly vary in some slight degree: and that the kind of variation, though much less in degree, is similar to that of domestic organisms. It is highly probable that every organic being, if subjected during several generations to new and varying conditions, would vary. It is certain that organisms, living in an isolated country which is undergoing geological changes, must in the course of time be so subjected to new conditions; moreover an organism, when by chance transported into a new station, for instance into an island, will often be exposed to new conditions, and be surrounded by a new series of organic beings. If there were no power at work selecting every slight variation, which opened new sources of subsistence to a being thus situated, the effects of crossing, the chance of death and the constant tendency to reversion to the old parent-form, would prevent the production of new races. If there were any selective agency at work, it seems impossible to assign any limit{508} to the complexity and beauty of the adaptive structures, which might thus be produced: for certainly the limit of possible variation of organic beings, either in a wild or domestic state, is not known. It was then shown, from the geometrically increasing tendency of each species to multiply (as evidenced from what we know of mankind and {241} of other animals when favoured by circumstances), and from the means of subsistence of each species on an average remaining constant, that during some part of the life of each, or during every few generations, there must be a severe struggle for existence; and that less than a grain{509} in the balance will determine which individuals shall live and which perish. In a country, therefore, undergoing changes, and cut off from the free immigration of species better adapted to the new station and conditions, it cannot be doubted that there is a most powerful means of selection, tending to preserve even the slightest variation, which aided the subsistence or defence of those organic beings, during any part of their whole existence, whose organization had been rendered plastic. Moreover, in animals in which the sexes are distinct, there is a sexual struggle, by which the most vigorous, and consequently the best adapted, will oftener procreate their kind. A new race thus formed by natural selection would be undistinguishable from a species. For comparing, on the one hand, the several species of a genus, and on the other hand several domestic races from a common stock, we cannot discriminate them by the amount of external difference, but only, first, by domestic races not remaining so constant or being so “true” as species are; and secondly by races always producing fertile offspring when crossed. And it was then shown that a race naturally selected—from the variation being slower—from the selection steadily leading towards the same ends{510}, and from every new slight change in structure being adapted (as is implied by its selection){242} to the new conditions and being fully exercised, and lastly from the freedom from occasional crosses with other species, would almost necessarily be “truer” than a race selected by ignorant or capricious and short-lived man. With respect to the sterility of species when crossed, it was shown not to be a universal character, and when present to vary in degree: sterility also was shown probably to depend less on external than on constitutional differences. And it was shown that when individual animals and plants are placed under new conditions, they become, without losing their healths, as sterile, in the same manner and to the same degree, as hybrids; and it is therefore conceivable that the cross-bred offspring between two species, having different constitutions, might have its constitution affected in the same peculiar manner as when an individual animal or plant is placed under new conditions. Man in selecting domestic races has little wish and still less power to adapt the whole frame to new conditions; in nature, however, where each species survives by a struggle against other species and external nature, the result must be very different. Races descending from the same stock were then compared with species of the same genus, and they were found to present some striking analogies. The offspring also of races when crossed, that is mongrels, were compared with the cross-bred offspring of species, that is hybrids, and they were found to resemble each other in all their characters, with the one exception of sterility, and even this, when present, often becomes after some generations variable in degree. The chapter was summed up, and it was shown that no ascertained limit to the amount of variation is known; or could be predicted with due time and changes of condition granted. It was then admitted that although the production of new races, undistinguishable from {243} true species, is probable, we must look to the relations in the past and present geographical distribution of the infinitely numerous beings, by which we are surrounded—to their affinities and to their structure—for any direct evidence. In the third chapter the inheritable variations in the mental phenomena of domestic and of wild organic beings were considered. It was shown that we are not concerned in this work with the first origin of the leading mental qualities; but that tastes, passions, dispositions, consensual movements, and habits all became, either congenitally or during mature life, modified and were inherited. Several of these modified habits were found to correspond in every essential character with true instincts, and they were found to follow the same laws. Instincts and dispositions &c. are fully as important to the preservation and increase of a species as its corporeal structure; and therefore the natural means of selection would act on and modify them equally with corporeal structures. This being granted, as well as the proposition that mental phenomena are variable, and that the modifications are inheritable, the possibility of the several most complicated instincts being slowly acquired was considered, and it was shown from the very imperfect series in the instincts of the animals now existing, that we are not justified in prima facie rejecting a theory of the common descent of allied organisms from the difficulty of imagining the transitional stages in the various now most complicated and wonderful instincts. We were thus led on to consider the same question with respect both to highly complicated organs, and to the aggregate of several such organs, that is individual organic beings; and it was shown, by the same method of taking the existing most imperfect series, that we ought not at once to reject the theory, because we cannot trace the transitional {244} stages in such organs, or conjecture the transitional habits of such individual species. In the Second Part{511} the direct evidence of allied forms having descended from the same stock was discussed. It was shown that this theory requires a long series of intermediate forms between the species and groups in the same classes—forms not directly intermediate between existing species, but intermediate with a common parent. It was admitted that if even all the preserved fossils and existing species were collected, such a series would be far from being formed; but it was shown that we have not good evidence that the oldest known deposits are contemporaneous with the first appearance of living beings; or that the several subsequent formations are nearly consecutive; or that any one formation preserves a nearly perfect fauna of even the hard marine organisms, which lived in that quarter of the world. Consequently, we have no reason to suppose that more than a small fraction of the organisms which have lived at any one period have ever been preserved; and hence that we ought not to expect to discover the fossilised sub-varieties between any two species. On the other hand, the evidence, though extremely imperfect, drawn from fossil remains, as far as it does go, is in favour of such a series of organisms having existed as that required. This want of evidence of the past existence of almost infinitely numerous intermediate forms, is, I conceive, much the weightiest difficulty{512} on the theory of common descent; but I must think that this is due to ignorance necessarily resulting from the imperfection of all geological records. {245} In the fifth chapter it was shown that new species gradually{513} appear, and that the old ones gradually disappear, from the earth; and this strictly accords with our theory. The extinction of species seems to be preceded by their rarity; and if this be so, no one ought to feel more surprise at a species being exterminated than at its being rare. Every species which is not increasing in number must have its geometrical tendency to increase checked by some agency seldom accurately perceived by us. Each slight increase in the power of this unseen checking agency would cause a corresponding decrease in the average numbers of that species, and the species would become rarer: we feel not the least surprise at one species of a genus being rare and another abundant; why then should we be surprised at its extinction, when we have good reason to believe that this very rarity is its regular precursor and cause. In the sixth chapter the leading facts in the geographical distribution of organic beings were considered—namely, the dissimilarity in areas widely and effectually separated, of the organic beings being exposed to very similar conditions (as for instance, within the tropical forests of Africa and America, or on the volcanic islands adjoining them). Also the striking similarity and general relations of the inhabitants of the same great continents, conjoined with a lesser degree of dissimilarity in the inhabitants living on opposite sides of the barriers intersecting it—whether or not these opposite sides are exposed to similar conditions. Also the dissimilarity, though in a still lesser degree, in the inhabitants of different islands in the same archipelago, together with their similarity taken as a {246} whole with the inhabitants of the nearest continent, whatever its character may be. Again, the peculiar relations of Alpine floras; the absence of mammifers on the smaller isolated islands; and the comparative fewness of the plants and other organisms on islands with diversified stations; the connection between the possibility of occasional transportal from one country to another, with an affinity, though not identity, of the organic beings inhabiting them. And lastly, the clear and striking relations between the living and the extinct in the same great divisions of the world; which relation, if we look very far backward, seems to die away. These facts, if we bear in mind the geological changes in progress, all simply follow from the proposition of allied organic beings having lineally descended from common parent-stocks. On the theory of independent creations they must remain, though evidently connected together, inexplicable and disconnected. In the seventh chapter, the relationship or grouping of extinct and recent species; the appearance and disappearance of groups; the ill-defined objects of the natural classification, not depending on the similarity of organs physiologically important, not being influenced by adaptive or analogical characters, though these often govern the whole economy of the individual, but depending on any character which varies least, and especially on the forms through which the embryo passes, and, as was afterwards shown, on the presence of rudimentary and useless organs. The alliance between the nearest species in distinct groups being general and not especial; the close similarity in the rules and objects in classifying domestic races and true species. All these facts were shown to follow on the natural system being a genealogical system. In the eighth chapter, the unity of structure throughout large groups, in species adapted to the {247} most different lives, and the wonderful metamorphosis (used metaphorically by naturalists) of one part or organ into another, were shown to follow simply on new species being produced by the selection and inheritance of successive small changes of structure. The unity of type is wonderfully manifested by the similarity of structure, during the embryonic period, in the species of entire classes. To explain this it was shown that the different races of our domestic animals differ less, during their young state, than when full grown; and consequently, if species are produced like races, the same fact, on a greater scale, might have been expected to hold good with them. This remarkable law of nature was attempted to be explained through establishing, by sundry facts, that slight variations originally appear during all periods of life, and that when inherited they tend to appear at the corresponding period of life; according to these principles, in several species descended from the same parent-stock, their embryos would almost necessarily much more closely resemble each other than they would in their adult state. The importance of these embryonic resemblances, in making out a natural or genealogical classification, thus becomes at once obvious. The occasional greater simplicity of structure in the mature animal than in the embryo; the gradation in complexity of the species in the great classes; the adaptation of the larvæ of animals to independent powers of existence; the immense difference in certain animals in their larval and mature states, were all shown on the above principles to present no difficulty. In the «ninth» chapter, the frequent and almost general presence of organs and parts, called by naturalists abortive or rudimentary, which, though formed with exquisite care, are generally absolutely useless «was considered». «These structures,» though {248} sometimes applied to uses not normal,—which cannot be considered as mere representative parts, for they are sometimes capable of performing their proper function,—which are always best developed, and sometimes only developed, during a very early period of life,—and which are of admitted high importance in classification,—were shown to be simply explicable on our theory of common descent. Why do we wish to reject the theory of common descent? Thus have many general facts, or laws, been included under one explanation; and the difficulties encountered are those which would naturally result from our acknowledged ignorance. And why should we not admit this theory of descent{514}? Can it be shown that organic beings in a natural state are all absolutely invariable? Can it be said that the limit of variation or the number of varieties capable of being formed under domestication are known? Can any distinct line be drawn between a race and a species? To these three questions we may certainly answer in the negative. As long as species were thought to be divided and defined by an impassable barrier of sterility, whilst we were ignorant of geology, and imagined that the world was of short duration, and the number of its past inhabitants few, we were justified in assuming individual creations, or in saying with Whewell that the beginnings of all things are hidden from man. Why then do we feel so strong an inclination to reject this theory—especially when the actual case of any two species, or even of any two races, is adduced—and one is asked, have these two originally descended from the same parent womb? I believe it is because we are {249} always slow in admitting any great change of which we do not see the intermediate steps. The mind cannot grasp the full meaning of the term of a million or hundred million years, and cannot consequently add up and perceive the full effects of small successive variations accumulated during almost infinitely many generations. The difficulty is the same with that which, with most geologists, it has taken long years to remove, as when Lyell propounded that great valleys{515} were hollowed out [and long lines of inland cliffs had been formed] by the slow action of the waves of the sea. A man may long view a grand precipice without actually believing, though he may not deny it, that thousands of feet in thickness of solid rock once extended over many square miles where the open sea now rolls; without fully believing that the same sea which he sees beating the rock at his feet has been the sole removing power. Shall we then allow that the three distinct species of rhinoceros{516} which separately inhabit Java and Sumatra and the neighbouring mainland of Malacca were created, male and female, out of the inorganic materials of these countries? Without any adequate cause, as far as our reason serves, shall we say that they were merely, from living near each other, created very like each other, so as to form a section of the genus dissimilar from the African section, some of the species of which section inhabit very similar and some very dissimilar stations? Shall we say that without any apparent cause they were created on the same generic type with the ancient woolly rhinoceros of Siberia and of the other species which formerly inhabited the same main division of the world: that they were created, less {250} and less closely related, but still with interbranching affinities, with all the other living and extinct mammalia? That without any apparent adequate cause their short necks should contain the same number of vertebræ with the giraffe; that their thick legs should be built on the same plan with those of the antelope, of the mouse, of the hand of the monkey, of the wing of the bat, and of the fin of the porpoise. That in each of these species the second bone of their leg should show clear traces of two bones having been soldered and united into one; that the complicated bones of their head should become intelligible on the supposition of their having been formed of three expanded vertebræ; that in the jaws of each when dissected young there should exist small teeth which never come to the surface. That in possessing these useless abortive teeth, and in other characters, these three rhinoceroses in their embryonic state should much more closely resemble other mammalia than they do when mature. And lastly, that in a still earlier period of life, their arteries should run and branch as in a fish, to carry the blood to gills which do not exist. Now these three species of rhinoceros closely resemble each other; more closely than many generally acknowledged races of our domestic animals; these three species if domesticated would almost certainly vary, and races adapted to different ends might be selected out of such variations. In this state they would probably breed together, and their offspring would possibly be quite, and probably in some degree, fertile; and in either case, by continued crossing, one of these specific forms might be absorbed and lost in another. I repeat, shall we then say that a pair, or a gravid female, of each of these three species of rhinoceros, were separately created with deceptive appearances of true relationship, with the stamp of inutility on {251} some parts, and of conversion in other parts, out of the inorganic elements of Java, Sumatra and Malacca? or have they descended, like our domestic races, from the same parent-stock? For my own part I could no more admit the former proposition than I could admit that the planets move in their courses, and that a stone falls to the ground, not through the intervention of the secondary and appointed law of gravity, but from the direct volition of the Creator. Before concluding it will be well to show, although this has incidentally appeared, how far the theory of common descent can legitimately be extended{517}. If we once admit that two true species of the same genus can have descended from the same parent, it will not be possible to deny that two species of two genera may also have descended from a common stock. For in some families the genera approach almost as closely as species of the same genus; and in some orders, for instance in the monocotyledonous plants, the families run closely into each other. We do not hesitate to assign a common origin to dogs or cabbages, because they are divided into groups analogous to the groups in nature. Many naturalists indeed admit that all groups are artificial; and that they depend entirely on the extinction of intermediate species. Some naturalists, however, affirm that though driven from considering sterility as the characteristic of species, that an entire incapacity to propagate together is the best evidence of the existence of natural genera. Even if we put on one side the undoubted fact that some species of the same genus {252} will not breed together, we cannot possibly admit the above rule, seeing that the grouse and pheasant (considered by some good ornithologists as forming two families), the bull-finch and canary-bird have bred together. No doubt the more remote two species are from each other, the weaker the arguments become in favour of their common descent. In species of two distinct families the analogy, from the variation of domestic organisms and from the manner of their intermarrying, fails; and the arguments from their geographical distribution quite or almost quite fails. But if we once admit the general principles of this work, as far as a clear unity of type can be made out in groups of species, adapted to play diversified parts in the economy of nature, whether shown in the structure of the embryonic or mature being, and especially if shown by a community of abortive parts, we are legitimately led to admit their community of descent. Naturalists dispute how widely this unity of type extends: most, however, admit that the vertebrata are built on one type; the articulata on another; the mollusca on a third; and the radiata on probably more than one. Plants also appear to fall under three or four great types. On this theory, therefore, all the organisms yet discovered are descendants of probably less than ten parent-forms. Conclusion. My reasons have now been assigned for believing that specific forms are not immutable creations{518}. The terms used by naturalists of affinity, unity of type, adaptive characters, the metamorphosis and {253} abortion of organs, cease to be metaphorical expressions and become intelligible facts. We no longer look at an organic being as a savage does at a ship{519} or other great work of art, as at a thing wholly beyond his comprehension, but as a production that has a history which we may search into. How interesting do all instincts become when we speculate on their origin as hereditary habits, or as slight congenital modifications of former instincts perpetuated by the individuals so characterised having been preserved. When we look at every complex instinct and mechanism as the summing up of a long history of contrivances, each most useful to its possessor, nearly in the same way as when we look at a great mechanical invention as the summing up of the labour, the experience, the reason, and even the blunders of numerous workmen. How interesting does the geographical distribution of all organic beings, past and present, become as throwing light on the ancient geography of the world. Geology loses glory{520} from the imperfection of its archives, but it gains in the immensity of its subject. There is much grandeur in looking at every existing organic being either as the lineal successor of some form now buried under thousands of feet of solid rock, or as being the co-descendant of that buried form of some more ancient and utterly lost inhabitant of this world. It accords with what we know of the laws impressed by the Creator{521} on matter that the production and extinction of forms should, like the birth and death of individuals, be {254} the result of secondary means. It is derogatory that the Creator of countless Universes should have made by individual acts of His will the myriads of creeping parasites and worms, which since the earliest dawn of life have swarmed over the land and in the depths of the ocean. We cease to be astonished{522} that a group of animals should have been formed to lay their eggs in the bowels and flesh of other sensitive beings; that some animals should live by and even delight in cruelty; that animals should be led away by false instincts; that annually there should be an incalculable waste of the pollen, eggs and immature beings; for we see in all this the inevitable consequences of one great law, of the multiplication of organic beings not created immutable. From death, famine, and the struggle for existence, we see that the most exalted end which we are capable of conceiving, namely, the creation of the higher animals{523}, has directly proceeded. Doubtless, our first impression is to disbelieve that any secondary law could produce infinitely numerous organic beings, each characterised by the most exquisite workmanship and widely extended adaptations: it at first accords better with our faculties to suppose that each required the fiat of a Creator. There{524} is a [simple] grandeur in this view of life with its several powers of growth, reproduction and of sensation, having been originally breathed into matter under a few forms, perhaps into only one{525}, {255} and that whilst this planet has gone cycling onwards according to the fixed laws of gravity and whilst land and water have gone on replacing each other—that from so simple an origin, through the selection of infinitesimal varieties, endless forms most beautiful and most wonderful have been evolved.

References

See the extracts in Life and Letters of Charles Darwin, ii. p. 5. {2} The second volume,—especially important in regard to Evolution,—reached him in the autumn of 1832, as Prof. Judd has pointed out in his most interesting paper in Darwin and Modern Science. Cambridge, 1909. {3} Obituary Notice of C. Darwin, Proc. R. Soc. vol. 44. Reprinted in Huxley's Collected Essays. See also Life and Letters of C. Darwin, ii. p. 179. {4} See the extracts in the Life and Letters, ii. p. 5. {5} Life and Letters, i. p. 82. {6} Obituary Notice, loc. cit. {7} Darwin and Modern Science. {8} Huxley, Obituary, p. xi. {9} In this citation the italics are mine. {10} Journal of Researches, Ed. 1860, p. 394. {11} F. Darwin’s Life of Charles Darwin (in one volume), 1892, p. 166. {12} Life and Letters, i. p. 83. {13} Life and Letters, ii. p. 8. {14} Avestruz Petise, i.e. Rhea Darwini. {15} A bird. {16} Life and Letters, i. p. 84. {17} It contains as a fact 231 pp. It is a strongly bound folio, interleaved with blank pages, as though for notes and additions. His own MS. from which it was copied contains 189 pp. {18} Life and Letters, ii. p. 116. {19} Life and Letters, ii. p. 10. {20} Life and Letters, ii. p. 146. {21} J. Linn. Soc. Zool. iii. p. 45. {22} It is evident that Parts and Chapters were to some extent interchangeable in the author’s mind, for p. 1 (of the MS. we have been discussing) is headed in ink Chapter I, and afterwards altered in pencil to Part I. {23} On p. 23 of the MS. of the Foundations is a reference to the “back of p. 21 bis”: this suggests that additional pages had been interpolated in the MS. and that it may once have had 37 in place of 35 pp. {24} Life and Letters, i. p. 153. {25} Life and Letters, i. p. 84. {26} In the footnotes to the Essay of 1844 attention is called to similar passages. {27} Life and Letters, ii. p. 15. {28} The passage is given in the Life and Letters, ii. p. 124. {29} The extract consists of the section on Natural Means of Selection, p. 87. {30} Life and Letters, i. p. 84. {31} Life and Letters, ii. p. 18. {32} Mrs Darwin’s brother. {33} After Mr Strickland’s name comes the following sentence, which has been erased, but remains legible. “Professor Owen would be very good; but I presume he would not undertake such a work.” {34} The words “several years ago, and” seem to have been added at a later date. {35} Life and Letters, ii. p. 9. {36} Evidently a memorandum that an example should be given. {37} The importance of exposure to new conditions for several generations is insisted on in the Origin, Ed. i. p. 7, also p. 131. In the latter passage the author guards himself against the assumption that variations are “due to chance,” and speaks of “our ignorance of the cause of each particular variation.” These statements are not always remembered by his critics. {38} Cf. Origin, Ed. i. p. 10, vi. p. 9, “Young of the same litter, sometimes differ considerably from each other, though both the young and the parents, as Müller has remarked, have apparently been exposed to exactly the same conditions of life.” {39} This is paralleled by the conclusion in the Origin, Ed. i. p. 8, that “the most frequent cause of variability may be attributed to the male and female reproductive elements having been affected prior to the act of conception.” {40} The meaning seems to be that there must be some variability in the liver otherwise anatomists would not speak of the ‘beau ideal’ of that organ. {41} The position of the following passage is uncertain. “If individuals of two widely different varieties be allowed to cross, a third race will be formed—a most fertile source of the variation in domesticated animals. «In the Origin, Ed. i. p. 20 the author says that “the possibility of making distinct races by crossing has been greatly exaggerated.”» If freely allowed, the characters of pure parents will be lost, number of races thus «illegible» but differences «?» besides the «illegible». But if varieties differing in very slight respects be allowed to cross, such small variation will be destroyed, at least to our senses,—a variation [clearly] just to be distinguished by long legs will have offspring not to be so distinguished. Free crossing great agent in producing uniformity in any breed. Introduce tendency to revert to parent form.” {42} The swamping effect of intercrossing is referred to in the Origin, Ed. i. p. 103, vi. p. 126. {43} A discussion on the intercrossing of hermaphrodites in relation to Knight’s views occurs in the Origin, Ed. i. p. 96, vi. p. 119. The parallelism between crossing and changed conditions is briefly given in the Origin, Ed. i. p. 267, vi. p. 391, and was finally investigated in The Effects of Cross and Self-Fertilisation in the Vegetable Kingdom, 1876. {44} There is an article on the vis medicatrix in Brougham’s Dissertations, 1839, a copy of which is in the author’s library. {45} This is the classification of selection into methodical and unconscious given in the Origin, Ed. i. p. 33, vi. p. 38. {46} This passage, and a similar discussion on the power of the Creator (p. 6), correspond to the comparison between the selective capacities of man and nature, in the Origin, Ed. i. p. 83, vi. p. 102. {47} i.e. they are individually distinguishable. {48} See Origin, Ed. i. p. 133, vi. p. 165. {49} When the author wrote this sketch he seems not to have been so fully convinced of the general occurrence of variation in nature as he afterwards became. The above passage in the text possibly suggests that at this time he laid more stress on sports or mutations than was afterwards the case. {50} The author may possibly have taken the case of the woodpecker from Buffon, Histoire Nat. des Oiseaux, T. vii. p. 3, 1780, where however it is treated from a different point of view. He uses it more than once, see for instance Origin, Ed. i. pp. 3, 60, 184, vi. pp. 3, 76, 220. The passage in the text corresponds with a discussion on the woodpecker and the mistletoe in Origin, Ed. i. p. 3, vi. p. 3. {51} This illustration occurs in the Origin, Ed. i. pp. 90, 91, vi. pp. 110, 111. {52} See Origin, Ed. i. p. 83, vi. p. 102, where the word Creator is replaced by Nature. {53} Note in the original. “Good place to introduce, saying reasons hereafter to be given, how far I extend theory, say to all mammalia—reasons growing weaker and weaker.” {54} See Origin, Ed. i. pp. 62, 63, vi. p. 77, where similar reference is made to De Candolle; for Malthus see Origin, p. 5. {55} This may possibly refer to the amount of destruction going on. See Origin, Ed. i. p. 68, vi. p. 84, where there is an estimate of a later date as to death-rate of birds in winter. “Calculate robins” probably refers to a calculation of the rate of increase of birds under favourable conditions. {56} In the Origin, Ed. i. pp. 64, 65, vi. p. 80, he instances cattle and horses and certain plants in S. America and American species of plants in India, and further on, as unexpected effects of changed conditions, the enclosure of a heath, and the relation between the fertilisation of clover and the presence of cats (Origin, Ed. i. p. 74, vi. p. 91). {57} Origin, Ed. i. p. 74, vi. p. 91. “It has been observed that the trees now growing on ... ancient Indian mounds ... display the same beautiful diversity and proportion of kinds as in the surrounding virgin forests.” {58} The simile of the wedge occurs in the Origin, Ed. i. p. 67; it is deleted in Darwin’s copy of the first edition: it does not occur in Ed. vi. {59} In a rough summary at the close of the Essay, occur the words:—“Every creature lives by a struggle, smallest grain in balance must tell.” {60} Cf. Origin, Ed. i. p. 77, vi. p. 94. {61} This is a repetition of what is given at p. 6. {62} Compare Origin, Ed. i. p. 41, vi. p. 47. “I have seen it gravely remarked, that it was most fortunate that the strawberry began to vary just when gardeners began to attend closely to this plant. No doubt the strawberry had always varied since it was cultivated, but the slight varieties had been neglected.” {63} Here we have the two types of sexual selection discussed in the Origin, Ed. i. pp. 88 et seq., vi. pp. 108 et seq. {64} It is not obvious why the author objects to “chance” or “external conditions making a woodpecker.” He allows that variation is ultimately referable to conditions and that the nature of the connexion is unknown, i.e. that the result is fortuitous. It is not clear in the original to how much of the passage the two ? refer. {65} The meaning is “That sterility is not universal is admitted by all.” {66} See Var. under Dom., Ed. 2, i. p. 388, where the garden forms of Gladiolus and Calceolaria are said to be derived from crosses between distinct species. Herbert’s hybrid Crinums are discussed in the Origin, Ed. i. p. 250, vi. p. 370. It is well known that the author believed in a multiple origin of domestic dogs. {67} The argument from gradation in sterility is given in the Origin, Ed. i. pp. 248, 255, vi. pp. 368, 375. In the Origin, I have not come across the cases mentioned, viz. crocus, heath, or grouse and fowl or peacock. For sterility between closely allied species, see Origin, Ed. i. p. 257, vi. p. 377. In the present essay the author does not distinguish between fertility between species and the fertility of the hybrid offspring, a point on which he insists in the Origin, Ed. i. p. 245, vi. p. 365. {68} Ackermann (Ber. d. Vereins f. Naturkunde zu Kassel, 1898, p. 23) quotes from Gloger that a cross has been effected between a domestic hen and a Tetrao tetrix; the offspring died when three days old. {69} No doubt the sexual cells are meant. I do not know on what evidence it is stated that the mule has bred. {70} The sentence is all but illegible. I think that the author refers to forms usually ranked as varieties having been marked as species when it was found that they were sterile together. See the case of the red and blue Anagallis given from Gärtner in the Origin, Ed. i. p. 247, vi. p. 368. {71} In the Origin, Ed. i. p. 258, where the author speaks of constitutional differences in this connexion, he specifies that they are confined to the reproductive system. {72} The sensitiveness of the reproductive system to changed conditions is insisted on in the Origin, Ed. i. p. 8, vi. p. 10. The ferret is mentioned, as being prolific in captivity, in Var. under Dom., Ed. 2, ii. p. 90. {73} Lindley’s remark is quoted in the Origin, Ed. i. p. 9. Linnæus’ remark is to the effect that Alpine plants tend to be sterile under cultivation (see Var. under Dom., Ed. 2, ii. p. 147). In the same place the author speaks of peat-loving plants being sterile in our gardens,—no doubt the American bog-plants referred to above. On the following page (p. 148) the sterility of the lilac (Syringa persica and chinensis) is referred to. {74} The author probably means that the increase in the petals is due to a greater food supply being available for them owing to sterility. See the discussion in Var. under Dom., Ed. 2, ii. p. 151. It must be noted that doubleness of the flower may exist without noticeable sterility. {75} I have not come across this case in the author’s works. {76} For the somewhat doubtful case of the cheetah (Felis jubata) see Var. under Dom., Ed. 2, ii. p. 133. I do not know to what fact “pig in India” refers. {77} This sentence should run “on which depends their incapacity to breed in unnatural conditions.” {78} This sentence ends in confusion: it should clearly close with the words “refused to breed” in place of the bracket and the present concluding phrase. {79} The author doubtless refers to the change produced by the summation of variation by means of selection. {80} The meaning of this sentence is made clear by a passage in the MS. of 1844:—“Until man selects two varieties from the same stock, adapted to two climates or to other different external conditions, and confines each rigidly for one or several thousand years to such conditions, always selecting the individuals best adapted to them, he cannot be said to have even commenced the experiment.” That is, the attempt to produce mutually sterile domestic breeds. {81} This passage is to some extent a repetition of a previous one and may have been intended to replace an earlier sentence. I have thought it best to give both. In the Origin, Ed. i. p. 141, vi. p. 176, the author gives his opinion that the power of resisting diverse conditions, seen in man and his domestic animals, is an example “of a very common flexibility of constitution.” {82} In the Origin, Ed. i. Chs. I. and V., the author does not admit reproduction, apart from environment, as being a cause of variation. With regard to the cumulative effect of new conditions there are many passages in the Origin, Ed. i. e.g. pp. 7, 12, vi. pp. 8, 14. {83} As already pointed out, this is the important principle investigated in the author’s Cross and Self-Fertilisation. Professor Bateson has suggested to me that the experiments should be repeated with gametically pure individuals. {84} In the Origin a chapter is given up to “difficulties on theory”: the discussion in the present essay seems slight even when it is remembered how small a space is here available. For Tibia &c. see p. 48. {85} This may be interpreted “The general structure of a bat is the same as that of non-flying mammals.” {86} That is truly winged fish. {87} The terrestrial woodpecker of S. America formed the subject of a paper by Darwin, Proc. Zool. Soc., 1870. See Life and Letters, vol. iii. p. 153. {88} The same proviso occurs in the Origin, Ed. i. p. 207, vi. p. 319. {89} The tameness of the birds in the Galapagos is described in the Journal of Researches (1860), p. 398. Dogs and rabbits are probably mentioned as cases in which the hereditary fear of man has been lost. In the 1844 MS. the author states that the Cuban feral dog shows great natural wildness, even when caught quite young. {90} In the Origin, Ed. i. p. 207, vi. p. 319, he refuses to define instinct. For Lord Brougham’s definition see his Dissertations on Subjects of Science etc., 1839, p. 27. {91} See James Hogg (the Ettrick Shepherd), Works, 1865, Tales and Sketches, p. 403. {92} This refers to the tailor-bird making use of manufactured thread supplied to it, instead of thread twisted by itself. {93} Often lost applies to instinct: birds get wilder is printed in a parenthesis because it was apparently added as an after-thought. Nest without roof refers to the water-ousel omitting to vault its nest when building in a protected situation. {94} In the MS. of 1844 is an interesting discussion on faculty as distinct from instinct. {95} At this date and for long afterwards the inheritance of acquired characters was assumed to occur. {96} Part II. is here intended: see the Introduction. {97} The meaning is that the attitude assumed in shamming is not accurately like that of death. {98} This refers to the transandantes sheep mentioned in the MS. of 1844, as having acquired a migratory instinct. {99} In the Origin, Ed. i. p. 209, vi. p. 321, Mozart’s pseudo-instinctive skill in piano-playing is mentioned. See Phil. Trans., 1770, p. 54. {100} In the discussion on bees’ cells, Origin, Ed. i. p. 225, vi. p. 343, the author acknowledges that his theory originated in Waterhouse’s observations. {101} The hawfinch-and Sylvia-types are figured in the Journal of Researches, p. 379. The discussion of change of form in relation to change of instinct is not clear, and I find it impossible to suggest a paraphrase. {102} I should interpret this obscure sentence as follows, “No such opposing law is known, but in all works on the subject a law is (in flat contradiction to all known facts) assumed to limit the possible amount of variation.” In the Origin, the author never limits the power of variation, as far as I know. {103} In Var. under Dom. Ed. 2, ii. p. 263, the Dahlia is described as showing sensitiveness to conditions in 1841. All the varieties of the Dahlia are said to have arisen since 1804 (ibid. i. p. 393). {104} In the original MS. the heading is: Part III.; but Part II. is clearly intended; for details see the Introduction. I have not been able to discover where § IV. ends and § V. begins. {105} This passage corresponds roughly to the conclusion of the Origin, see Ed. i. p. 482, vi. p. 661. {106} A similar passage occurs in the conclusion of the Origin, Ed. i. p. 481, vi. p. 659. {107} See Origin, Ed. i. p. 312, vi. p. 453. {108} See Origin, Ed. i. pp. 280, 281, vi. p. 414. The author uses his experience of pigeons for examples for what he means by intermediate; the instance of the horse and tapir also occurs. {109} The absence of intermediate forms between living organisms (and also as regards fossils) is discussed in the Origin, Ed. i. pp. 279, 280, vi. p. 413. In the above discussion there is no evidence that the author felt this difficulty so strongly as it is expressed in the Origin, Ed. i. p. 299,—as perhaps “the most obvious and gravest objection that can be urged against my theory.” But in a rough summary written on the back of the penultimate page of the MS. he refers to the geological evidence:—“Evidence, as far as it does go, is favourable, exceedingly incomplete,—greatest difficulty on this theory. I am convinced not insuperable.” Buckland’s remarks are given in the Origin, Ed. i. p. 329, vi. p. 471. {110} That the evidence of geology, as far as it goes, is favourable to the theory of descent is claimed in the Origin, Ed. i. pp. 343-345, vi. pp. 490-492. For the reference to net in the following sentence, see Note 1, p. 48, {Link:Note 161} of this Essay. {111} See Origin, Ed. i. p. 288, vi. p. 422. “The remains that do become embedded, if in sand and gravel, will, when the beds are upraised, generally be dissolved by the percolation of rain-water.” {112} The position of the following is not clear:—“Think of immense differences in nature of European deposits,—without interposing new causes,—think of time required by present slow changes, to cause, on very same area, such diverse deposits, iron-sand, chalk, sand, coral, clay!” {113} The paragraph which ends here is difficult to interpret. In spite of obscurity it is easy to recognize the general resemblance to the discussion on the importance of subsidence given in the Origin, Ed. i. pp. 290 et seq., vi. pp. 422 et seq. {114} See Note 3, p. 27. {115} Compare Origin, Ed. i. p. 298, vi. p. 437. “We shall, perhaps, best perceive the improbability of our being enabled to connect species by numerous, fine, intermediate, fossil links, by asking ourselves whether, for instance, geologists at some future period will be able to prove that our different breeds of cattle, sheep, horses, and dogs have descended from a single stock or from several aboriginal stocks.” {116} The sudden appearance of groups of allied species in the lowest known fossiliferous strata is discussed in the Origin, Ed. i. p. 306, vi. p. 446. The gradual appearance in the later strata occurs in the Origin, Ed. i. p. 312, vi. p. 453. {117} Compare Origin, Ed. i. p. 307, vi. p. 448. {118} I have interpreted as Sandstone a scrawl which I first read as Sea; I have done so at the suggestion of Professor Judd, who points out that “footprints in the red sandstone were known at that time, and geologists were not then particular to distinguish between Amphibians and Reptiles.” {119} This refers to Cuvier's discovery of Palæotherium &c. at Montmartre. {120} This simile is more fully given in the Origin, Ed. i. p. 310, vi. p. 452. “For my part, following out Lyell’s metaphor, I look at the natural geological record, as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a short chapter has been preserved; and of each page, only here and there a few lines. Each word of the slowly-changing language, in which the history is supposed to be written, being more or less different in the interrupted succession of chapters, may represent the apparently abruptly changed forms of life, entombed in our consecutive, but widely separated formations.” Professor Judd has been good enough to point out to me, that Darwin’s metaphor is founded on the comparison of geology to history in Ch. i. of the Principles of Geology, Ed. i. 1830, vol. i. pp. 1-4. Professor Judd has also called my attention to another passage,—Principles, Ed. i. 1833, vol. iii. p. 33, when Lyell imagines an historian examining “two buried cities at the foot of Vesuvius, immediately superimposed upon each other.” The historian would discover that the inhabitants of the lower town were Greeks while those of the upper one were Italians. But he would be wrong in supposing that there had been a sudden change from the Greek to the Italian language in Campania. I think it is clear that Darwin’s metaphor is partly taken from this passage. See for instance (in the above passage from the Origin) such phrases as “history ... written in a changing dialect”—“apparently abruptly changed forms of life.” The passage within [ ] in the above paragraph:—“Lyell’s views as far as they go &c.,” no doubt refers, as Professor Judd points out, to Lyell not going so far as Darwin on the question of the imperfection of the geological record. {121} On rarity and extinction see Origin, Ed. i. pp. 109, 319, vi. pp. 133, 461. {122} In the Origin, Ed. i. p. 346, vi. p. 493, the author begins his discussion on geographical distribution by minimising the effect of physical conditions. He lays great stress on the effect of barriers, as in the present Essay. {123} Note in the original, “Would it be more striking if we took animals, take Rhinoceros, and study their habitats?” {124} Note by Mr A. R. Wallace. “The want of similarity referred to, is, between the mountains of Brazil and Guiana and those of the Andes. Also those of the Indian peninsula as compared with the Himalayas. In both cases there is continuous intervening land. “The islands referred to were, no doubt, the Galapagos for dissimilarity from S. America; our own Islands as compared with Europe, and perhaps Java, for similarity with continental Asia.” {125} The arguments against multiple centres of creation are given in the Origin, Ed. i. p. 352, vi. p. 499. {126} In the Origin, Ed. i. p. 366, vi. p. 516, the author does not give his views on the distribution of alpine plants as original but refers to Edward Forbes’ work (Geolog. Survey Memoirs, 1846). In his autobiography, Darwin refers to this. “I was forestalled” he says, “in only one important point, which my vanity has always made me regret.” (Life and Letters, i. p. 88.) {127} «The following is written on the back of a page of the MS.» Discuss one or more centres of creation: allude strongly to facilities of dispersal and amount of geological change: allude to mountain-summits afterwards to be referred to. The distribution varies, as everyone knows, according to adaptation, explain going from N. to S. how we come to fresh groups of species in the same general region, but besides this we find difference, according to greatness of barriers, in greater proportion than can be well accounted for by adaptation. «On representive species see Origin, Ed. i. p. 349, vi. p. 496.» This very striking when we think of cattle of Pampas, plants «?» &c. &c. Then go into discussion; this holds with 3 or 4 main divisions as well as the endless minor ones in each of these 4 great ones: in these I chiefly refer to mammalia &c. &c. The similarity of type, but not in species, in same continent has been much less insisted on than the dissimilarity of different great regions generically: it is more striking. «I have here omitted an incomprehensible sentence.» Galapagos Islands, Tristan d’Acunha, volcanic islands covered with craters we know lately did not support any organisms. How unlike these islands in nature to neighbouring lands. These facts perhaps more striking than almost any others. [Geology apt to affect geography therefore we ought to expect to find the above.] Geological-geographical distribution. In looking to past times we find Australia equally distinct. S. America was distinct, though with more forms in common. N. America its nearest neighbour more in common,—in some respects more, in some less allied to Europe. Europe we find «?» equally European. For Europe is now part of Asia though not «illegible». Africa unknown,—examples, Elephant, Rhinoceros, Hippopotamus, Hyaena. As geology destroys geography we cannot be surprised in going far back we find Marsupials and Edentata in Europe: but geology destroys geography. {128} Rincon in Spanish means a nook or corner, it is here probably used to mean a small farm. {129} The following is written across the page: “No one would expect a set of similar varieties to be produced in the different countries, so species different.” {130} «The following passage seems to have been meant to follow here.» The parent of an organism, we may generally suppose to be in less favourable condition than the selected offspring and therefore generally in fewer numbers. (This is not borne out by horticulture, mere hypothesis; as an organism in favourable conditions might by selection be adapted to still more favourable conditions.) Barrier would further act in preventing species formed in one part migrating to another part. {131} «The following notes occur on the back of the page.» Number of species not related to capabilities of the country: furthermore not always those best adapted, perhaps explained by creationists by changes and progress. «See p. 34, note 1.» Although creationists can, by help of geology, explain much, how can he explain the marked relation of past and present in same area, the varying relation in other cases, between past and present, the relation of different parts of same great area. If island, to adjoining continent, if quite different, on mountain summits,—the number of individuals not being related to capabilities, or how &c.—our theory, I believe, can throw much light and all facts accord. {132} See Origin, Ed. i. p. 390, vi. p. 543. {133} On oscillation see Origin, Ed. i. p. 291, vi. p. 426. {134} «From the back of MS.» Effect of climate on stationary island and on continent, but continent once island. Moreover repeated oscillations fresh diffusion when non-united, then isolation, when rising again immigration prevented, new habitats formed, new species, when united free immigration, hence uniform characters. Hence more forms «on?» the island. Mountain summits. Why not true species. First let us recall in Part I, conditions of variation: change of conditions during several generations, and if frequently altered so much better [perhaps excess of food]. Secondly, continued selection [while in wild state]. Thirdly, isolation in all or nearly all,—as well to recall advantages of. [In continent, if we look to terrestrial animal, long continued change might go on, which would only cause change in numerical number «? proportions»: if continued long enough might ultimately affect all, though to most continents «there is» chance of immigration. Some few of whole body of species must be long affected and entire selection working same way. But here isolation absent, without barrier, cut off such «illegible». We can see advantage of isolation. But let us take case of island thrown up by volcanic agency at some distances, here we should have occasional visitants, only in few numbers and exposed to new conditions and «illegible» more important,—a quite new grouping of organic beings, which would open out new sources of subsistence, or «would» control «?» old ones. The number would be few, can old have the very best opportunity. «The conquest of the indigenes by introduced organisms shows that the indigenes were not perfectly adapted, see Origin, Ed. i. p. 390.» Moreover as the island continued changing,—continued slow changes, river, marshes, lakes, mountains &c. &c., new races as successively formed and a fresh occasional visitant. If island formed continent, some species would emerge and immigrate. Everyone admits continents. We can see why Galapagos and C. Verde differ «see Origin, Ed. i. p. 398»], depressed and raised. We can see from this repeated action and the time required for a continent, why many more forms than in New Zealand «see Origin, Ed. i. p. 389 for a comparison between New Zealand and the Cape» no mammals or other classes «see however, Origin, Ed. i. p. 393 for the case of the frog». We can at once see how it comes when there has been an old channel of migration,—Cordilleras; we can see why Indian Asiatic Flora,—[why species] having a wide range gives better chance of some arriving at new points and being selected, and adapted to new ends. I need hardly remark no necessity for change. Finally, as continent (most extinction «?» during formation of continent) is formed after repeated elevation and depression, and interchange of species we might foretell much extinction, and that the survivor would belong to same type, as the extinct, in same manner as different part of same continent, which were once separated by space as they are by time «see Origin, Ed. i. pp. 339 and 349». As all mammals have descended from one stock, we ought to expect that every continent has been at some time connected, hence obliteration of present ranges. I do not mean that the fossil mammifers found in S. America are the lineal successors «ancestors» of the present forms of S. America: for it is highly improbable that more than one or two cases (who will say how many races after Plata bones) should be found. I believe this from numbers, who have lived,—mere «?» chance of fewness. Moreover in every case from very existence of genera and species only few at one time will leave progeny, under form of new species, to distant ages; and the more distant the ages the fewer the progenitors. An observation may be here appended, bad chance of preservation on rising island, the nurseries of new species, appeal to experience «see Origin, Ed. i. p. 292». This observation may be extended, that in all cases, subsiding land must be, in early stages, less favourable to formation of new species; but it will isolate them, and then if land recommences rising how favourable. As preoccupation is bar to diffusion to species, so would it be to a selected variety. But it would not be if that variety was better fitted to some not fully occupied station; so during elevation or the formation of new stations, is scene for new species. But during elevation not favourable to preservation of fossil (except in caverns «?»); when subsidence highly favourable in early stages to preservation of fossils; when subsidence, less sediment. So that our strata, as general rule will be the tomb of old species (not undergoing any change) when rising land the nursery. But if there be vestige will generally be preserved to future ages, the new ones will not be entombed till fresh subsidence supervenes. In this long gap we shall have no record: so that wonderful if we should get transitional forms. I do not mean every stage, for we cannot expect that, as before shown, until geologists will be prepared to say that although under unnaturally favourable condition we can trace in future ages short-horn and Herefordshire «see note 2, p. 26». {135} After “organs” is inserted, apparently as an afterthought:—“no, and instance metamorphosis, afterwards explicable.” {136} For analogical resemblances see Origin, Ed. i. p. 427, vi. p. 582. {137} “Practically when naturalists are at work, they do not trouble themselves about the physiological value of the characters.... If they find a character nearly uniform,... they use it as one of high value,” Origin, Ed. i. p. 417, vi. p. 573. {138} “We are cautioned ... not to class two varieties of the pine-apple together, merely because their fruit, though the most important part, happens to be nearly identical,” Origin, Ed. i. p. 423, vi. p. 579. {139} The whole of this passage is obscure, but the text is quite clear, except for one illegible word. {140} «The exact position of the following passage is uncertain:» “just as it is not likely every present breed of fancy birds and cattle will propagate, only some of the best.” {141} This suggests that the author was not far from the principle of divergence on which he afterwards laid so much stress. See Origin, Ed. i. p. 111, vi. p. 134, also Life and Letters, i. p. 84. {142} That is to say the same conditions occurring in different parts of the globe. {143} The position of the following is uncertain, “greyhound and racehorse have an analogy to each other.” The same comparison occurs in the Origin, Ed. i. p. 427, vi. p. 583. {144} Air is evidently intended; in the MS. water is written twice. {145} Written between the lines occurs:—“extend to birds and other classes.” {146} Written between the lines occurs:—“many bones merely represented.” {147} In the Origin, Ed. i. p. 434, vi. p. 595, the term morphology is taken as including unity of type. The paddle of the porpoise and the wing of the bat are there used as instances of morphological resemblance. {148} The sentence is difficult to decipher. {149} In the Origin, Ed. i. p. 436, vi. p. 598, the author speaks of the “general pattern” being obscured in the paddles of “extinct gigantic sea-lizards.” {150} See Origin, Ed. i. p. 437, vi. p. 599. {151} The following passage seems to have been meant to precede the sentence beginning “These facts”:—“It is evident, that when in each individual species, organs are metamorph. a unity of type extends.” {152} This is, I believe, the first place in which the author uses the words “theory of descent.” {153} The sentence should probably run, “Let us take the case of the vertebrata: if we assume them to be descended from one parent, then by this theory they have been altered &c.” {154} That is “we should call it a morphological fact.” {155} In the Origin, Ed. i. p. 438, vi. p. 602, the author, referring to the expressions used by naturalists in regard to morphology and metamorphosis, says “On my view these terms may be used literally.” {156} See Origin, Ed. i. p. 439, vi. p. 605. {157} In the Origin, Ed. i. p. 440, vi. p. 606, the author argues that the “loop-like course of the arteries” in the vertebrate embryo has no direct relation to the conditions of existence. {158} The following passages are written across the page:—“They pass through the same phases, but some, generally called the higher groups, are further metamorphosed. ? Degradation and complication? no tendency to perfection. ? Justly argued against Lamarck?” {159} An almost identical passage occurs in the Origin, Ed. i. p. 440, vi. p. 606. {160} The following: “Deaths of brothers «when» old by same peculiar disease” which is written between the lines seems to have been a memorandum which is expanded a few lines lower. I believe the case of the brothers came from Dr R. W. Darwin. {161} See the discussion to this effect in the Origin, Ed. i. pp. 443-4, vi. p. 610. The author there makes the distinction between a cause affecting the germ-cell and the reaction occurring at a late period of life. {162} Possibly the sentence was meant to end “is not visible till then.” {163} See Origin, Ed. i. pp. 444-5, vi. p. 611. The query appended to much less is justified, since measurement was necessary to prove that the greyhound and bulldog puppies had not nearly acquired “their full amount of proportional difference.” {164} «The following discussion, from the back of the page, is in large measure the same as the text.» I think light can be thrown on these facts. From the following peculiarities being hereditary, [we know that some change in the germinal vesicle is effected, which will only betray itself years after] diseases—man, goitre, gout, baldness, fatness, size, [longevity «illegible» time of reproduction, shape of horns, case of old brothers dying of same disease]. And we know that the germinal vesicle must have been affected, though no effect is apparent or can be apparent till years afterwards,—no more apparent than when these peculiarities appear by the exposure of the full-grown individual. «That is, “the young individual is as apparently free from the hereditary changes which will appear later, as the young is actually free from the changes produced by exposure to certain conditions in adult life.”» So that when we see a variety in cattle, even if the variety be due to act of reproduction, we cannot feel sure at what period this change became apparent. It may have been effected during early age of free life «or» fœtal existence, as monsters show. From arguments before used, and crossing, we may generally suspect in germ; but I repeat it does not follow, that the change should be apparent till life fully developed; any more than fatness depending on heredity should be apparent during early childhood, still less during fœtal existence. In case of horns of cattle, which when inherited must depend on germinal vesicle, obviously no effect till cattle full-grown. Practically it would appear that the [hereditary] peculiarities characterising our domestic races, therefore resulting from vesicle, do not appear with their full characters in very early states; thus though two breeds of cows have calves different, they are not so different,—grey-hound and bull-dog. And this is what is «to» be expected, for man is indifferent to characters of young animals and hence would select those full-grown animals which possessed the desirable characteristics. So that from mere chance we might expect that some of the characters would be such only as became fully apparent in mature life. Furthermore we may suspect it to be a law, that at whatever time a new character appears, whether from vesicle, or effects of external conditions, it would appear at corresponding time «see Origin, Ed. i. p. 444». Thus diseases appearing in old age produce children with do.,—early maturity,—longevity,—old men, brothers, of same disease—young children of do. I said men do not select for quality of young,—calf with big bullocks. Silk-worms, peculiarities which, appear in caterpillar state or cocoon state, are transmitted to corresponding states. The effect of this would be that if some peculiarity was born in a young animal, but never exercised, it might be inherited in young animal; but if exercised that part of structure would be increased and would be inherited in corresponding time of life after such training. I have said that man selects in full-life, so would it be in Nature. In struggle of existence, it matters nothing to a feline animal, whether kitten eminently feline, as long as it sucks. Therefore natural selection would act equally well on character which was fully «developed» only in full age. Selection could tend to alter no character in fœtus, (except relation to mother) it would alter less in young state (putting on one side larva condition) but alter every part in full-grown condition. Look to a fœtus and its parent, and again after ages fœtus and its «i. e. the above mentioned parents» descendant; the parent more variable «?» than fœtus, which explains all. {165} Some of these examples occur in Origin, Ed. i. pp. 450-51, vi. pp. 619-20. {166} The two following sentences are written, one down the margin, the other across the page. “Abortive organs eminently useful in classification. Embryonic state of organs. Rudiments of organs.” {167} I imagine the meaning to be that abortive organs are specific characters in contrast to monstrosities. {168} Minute hanging horns are mentioned in the Origin, Ed. i. p. 454, vi. p. 625, as occurring in hornless breeds of cattle. {169} Linum flavum is dimorphic: thyme gynodiæcious. It is not clear what point is referred to under Geranium pyrenaicum. {170} The author’s work on duck’s wings &c. is in Var. under Dom., Ed. 2, i. p. 299. {171} The words vis medicatrix are inserted after “useless,” apparently as a memorandum. {172} In the male florets of certain Compositæ the style functions merely as a piston for forcing out the pollen. {173} «On the back of the page is the following.» If abortive organs are a trace preserved by hereditary tendency, of organ in ancestor of use, we can at once see why important in natural classification, also why more plain in young animal because, as in last section, the selection has altered the old animal most. I repeat, these wondrous facts, of parts created for no use in past and present time, all can by my theory receive simple explanation; or they receive none and we must be content with some such empty metaphor, as that of De Candolle, who compares creation to a well covered table, and says abortive organs may be compared to the dishes (some should be empty) placed symmetrically! {174} The author doubtless meant that the complex relationships between organisms can be roughly represented by a net in which the knots stand for species. {175} Between the lines occurs:—“one «?» form be lost.” {176} The original sentence is here broken up by the insertion of:—“out of the dust of Java, Sumatra, these «?» allied to past and present age and «illegible», with the stamp of inutility in some of their organs and conversion in others.” {177} Between the lines occur the words:—“Species vary according to same general laws as varieties; they cross according to same laws.” {178} “A cross with a bull-dog has affected for many generations the courage and obstinacy of greyhounds,” Origin, Ed. i. p. 214, vi. p. 327. {179} The simile of the savage and the ship occurs in the Origin, Ed. i. p. 485, vi. p. 665. {180} In the Origin, Ed. i. p. 486, vi. p. 665, the author speaks of the “summing up of many contrivances”: I have therefore introduced the above words which make the passage clearer. In the Origin the comparison is with “a great mechanical invention,”—not with a work of art. {181} See a similar passage in the Origin, Ed. i. p. 487, vi. p. 667. {182} See the Origin, Ed. i. p. 488, vi. p. 668. {183} The following discussion, together with some memoranda are on the last page of the MS. “The supposed creative spirit does not create either number or kind which «are» from analogy adapted to site (viz. New Zealand): it does not keep them all permanently adapted to any country,—it works on spots or areas of creation,—it is not persistent for great periods,—it creates forms of same groups in same regions, with no physical similarity,—it creates, on islands or mountain summits, species allied to the neighbouring ones, and not allied to alpine nature as shown in other mountain summits—even different on different island of similarly constituted archipelago, not created on two points: never mammifers created on small isolated island; nor number of organisms adapted to locality: its power seems influenced or related to the range of other species wholly distinct of the same genus,—it does not equally effect, in amount of difference, all the groups of the same class.” {184} This passage is the ancestor of the concluding words in the first edition of the Origin of Species which have remained substantially unchanged throughout subsequent editions, “There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” In the 2nd edition “by the Creator” is introduced after “originally breathed.” {185} Compare the Origin, Ed. i. p. 481, vi. p. 659, “The difficulty is the same as that felt by so many geologists, when Lyell first insisted that long lines of inland cliffs had been formed, and great valleys excavated, by the slow action of the coast-waves.” {186} The cumulative effect of domestication is insisted on in the Origin, see e.g. Origin, Ed. i. p. 7, vi. p. 8. {187} This type of variation passes into what he describes as the direct effect of conditions. Since they are due to causes acting during the adult life of the organism they might be called individual variations, but he uses this term for congenital variations, e.g. the differences discoverable in plants raised from seeds of the same pod (Origin, Ed. i. p. 45, vi. p. 53). {188} «It is not clear where the following note is meant to come»: Case of Orchis,—most remarkable as not long cultivated by seminal propagation. Case of varieties which soon acquire, like Ægilops and Carrot (and Maize) a certain general character and then go on varying. {189} Here, as in the MS. of 1842, the author is inclined to minimise the variation occurring in nature. {190} This is more strongly stated than in the Origin, Ed. i. p. 30. {191} See Origin, Ed. i. p. 13. {192} Origin, Ed. i. p. 86, vi. p. 105. {193} It is interesting to find that though the author, like his contemporaries, believed in the inheritance of acquired characters, he excluded the case of mutilation. {194} This corresponds to Origin, Ed. i. p. 10, vi. p. 9. {195} Origin, Ed. i. p. 8, vi. p. 10. {196} For plasticity see Origin, Ed. i. pp. 12, 132. {197} Var. under Dom., Ed. ii. I. p. 393. {198} Selection is here used in the sense of isolation, rather than as implying the summation of small differences. Professor Henslow in his Heredity of Acquired Characters in Plants, 1908, p. 2, quotes from Darwin’s Var. under Dom., Ed. i. II. p. 271, a passage in which the author, speaking of the direct action of conditions, says:—“A new sub-variety would thus be produced without the aid of selection.” Darwin certainly did not mean to imply that such varieties are freed from the action of natural selection, but merely that a new form may appear without summation of new characters. Professor Henslow is apparently unaware that the above passage is omitted in the second edition of Var. under Dom., II. p. 260. {199} See the Essay of 1842, p. 3. {200} See Origin, Ed. i. p. 33, vi. p. 38. The evidence is given in the present Essay rather more fully than in the Origin. {201} Journal of Researches, Ed. 1860, p. 214. “Doggies catch otters, old women no.” {202} The effects of crossing is much more strongly stated here than in the Origin. See Ed. i. p. 20, vi. p. 23, where indeed the opposite point of view is given. His change of opinion may be due to his work on pigeons. The whole of the discussion on crossing corresponds to Chapter VIII of the Origin, Ed. i. rather than to anything in the earlier part of the book. {203} The parallelism between the effects of a cross and the effects of conditions is given from a different point of view in the Origin, Ed. i. p. 266, vi. p. 391. See the experimental evidence for this important principle in the author’s work on Cross and Self-Fertilisation. Professor Bateson has suggested that the experiments should be repeated with gametically pure plants. {204} The so-called Knight-Darwin Law is often misunderstood. See Goebel in Darwin and Modern Science, 1909, p. 419; also F. Darwin, Nature, Oct. 27, 1898. {205} Pallas’ theory is discussed in the Origin, Ed. i. pp. 253, 254, vi. p. 374. {206} See Darwin’s paper on the fertility of hybrids from the common and Chinese goose in Nature, Jan. 1, 1880. {207} Origin, Ed. i. p. 19, vi. p. 22. {208} Var. under Dom., Ed. ii. vol. II. p. 211. {209} This discussion corresponds to the Origin, Ed. i. pp. 11 and 143, vi. pp. 13 and 177. {210} See Origin, Ed. i. p. 7, vi. p. 7. {211} «Note in the original.» “Isidore G. St Hilaire insists that breeding in captivity essential element. Schleiden on alkalies. «See Var. under Dom., Ed. ii. vol. II. p. 244, note 10.» What is it in domestication which causes variation?” {212} «Note in the original.» “It appears that slight changes of condition «are» good for health; that more change affects the generative system, so that variation results in the offspring; that still more change checks or destroys fertility not of the offspring.” Compare the Origin, Ed. i. p. 9, vi. p. 11. What the meaning of “not of the offspring” may be is not clear. {213} In the Origin, Ed. i. p. 41, vi. p. 46 the question is differently treated; it is pointed out that a large stock of individuals gives a better chance of available variations occurring. Darwin quotes from Marshall that sheep in small lots can never be improved. This comes from Marshall’s Review of the Reports to the Board of Agriculture, 1808, p. 406. In this Essay the name Marshall occurs in the margin. Probably this refers to loc. cit. p. 200, where unshepherded sheep in many parts of England are said to be similar owing to mixed breeding not being avoided. {214} See Origin, Ed. i. p. 8, vi. p. 8. {215} See Origin, Ed. i. p. 42, vi. p. 48. {216} «Note in the original.» There are white peacocks. {217} «Note in the original.» There are varieties of asparagus. {218} In Chapter II of the first edition of the Origin Darwin insists rather on the presence of variability in a state of nature; see, for instance, p. 45, Ed. vi. p. 53, “I am convinced that the most experienced naturalist would be surprised at the number of the cases of variability ... which he could collect on good authority, as I have collected, during a course of years.” {219} See Origin, Ed. i. p. 44, vi. p. 52. {220} «Note in the original.» Here discuss what is a species, sterility can most rarely be told when crossed.—Descent from common stock. {221} «Note in the original.» Give only rule: chain of intermediate forms, and analogy; this important. Every Naturalist at first when he gets hold of new variable type is quite puzzled to know what to think species and what variations. {222} The author had not at this time the knowledge of the meaning of dimorphism. {223} «Note in original.» Compare feathered heads in very different birds with spines in Echidna and Hedgehog. «In Variation under Domestication, Ed. ii. vol. II. p. 317, Darwin calls attention to laced and frizzled breeds occurring in both fowls and pigeons. In the same way a peculiar form of covering occurs in Echidna and the hedgehog.» Plants under very different climate not varying. Digitalis shows jumps «?» in variation, like Laburnum and Orchis case—in fact hostile cases. Variability of sexual characters alike in domestic and wild. {224} A corresponding passage occurs in Origin, Ed. i. p. 83, vi. p. 101, where however Nature takes the place of the selecting Being. {225} The mistletoe is used as an illustration in Origin, Ed. i. p. 3, vi. p. 3, but with less detail. {226} «Note in original.» The selection, in cases where adult lives only few hours as Ephemera, must fall on larva—curious speculation of the effect «which» changes in it would bring in parent. {227} This section forms part of the joint paper by Darwin and Wallace read before the Linnean Society on July 1, 1858. {228} Occurs in Origin, Ed. i. p. 64, vi. p. 79. {229} Corresponds approximately with Origin, Ed. i. pp. 64-65, vi. p. 80. {230} This simile occurs in Origin, Ed. i. p. 67, not in the later editions. {231} «Note in the original.» In case like mistletoe, it may be asked why not more species, no other species interferes; answer almost sufficient, same causes which check the multiplication of individuals. {232} See Origin, Ed. i. pp. 104, 292, vi. pp. 127, 429. {233} Recognition of the importance of minute differences in the struggle occurs in the Essay of 1842, p. 8 note 3. {234} See Origin, Ed. i. p. 90, vi. p. 110. {235} These two forms of sexual selection are given in Origin, Ed. i. p. 87, vi. p. 107. The Guiana rock-thrush is given as an example of bloodless competition. {236} «Note in original.» Seals? Pennant about battles of seals. {237} In the Linnean paper of July 1, 1858 the final word is mate: but the context shows that it should be male; it is moreover clearly so written in the MS. {238} In the Origin the author would here have used the word variety. {239} The whole of p. 94 and 15 lines of p. 95 are, in the MS., marked through in pencil with vertical lines, beginning at “Races produced, &c.” and ending with “to these conditions.” {240} See Origin, Ed. i. p. 83, vi. p. 102. {241} In the present Essay there is some evidence that the author attributed more to sports than was afterwards the case: but the above passage points the other way. It must always be remembered that many of the minute differences, now considered small mutations, are the small variations on which Darwin conceived selection to act. {242} See Var. under Dom., Ed. ii. vol. II. p. 230. {243} «Note in the original.» If domestic animals are descended from several species and become fertile inter se, then one can see they gain fertility by becoming adapted to new conditions and certainly domestic animals can withstand changes of climate without loss of fertility in an astonishing manner. {244} See Suchetet, L’Hybridité dans la Nature, Bruxelles, 1888, p. 67. In Var. under Dom., Ed. ii. vol. II. hybrids between the fowl and the pheasant are mentioned. I can give no information on the other cases. {245} Origin, Ed. i. p. 250, vi. p. 370. {246} This was the position of Gärtner and of Kölreuter: see Origin, Ed. i. pp. 246-7, vi. pp. 367-8. {247} «Note in the original.» Yet this seems introductory to the case of the heaths and crocuses above mentioned. «Herbert observed that crocus does not set seed if transplanted before pollination, but that such treatment after pollination has no sterilising effect. (Var. under Dom., Ed. ii. vol. II. p. 148.) On the same page is a mention of the Ericaceæ being subject to contabescence of the anthers. For Crinum see Origin, Ed. i. p. 250: for Rhododenron and Calceolaria see p. 251.» {248} «Note in original.» Animals seem more often made sterile by being taken out of their native condition than plants, and so are more sterile when crossed. We have one broad fact that sterility in hybrids is not closely related to external difference, and these are what man alone gets by selection. {249} See Var. under Dom., Ed. ii. vol. II. p. 132; for the case of the cheetah see loc cit. p. 133. {250} Var. under Dom., Ed. ii. vol. II. p. 148. {251} Quoted in the Origin, Ed. i. p. 9. {252} See Var. under Dom., Ed. ii. vol. II. p. 147. {253} Var. under Dom., Ed. ii. vol. II. p. 89. {254} See Var. under Dom., Ed. ii. vol. II. p. 147. {255} Origin, Ed. i. p. 267, vi. p. 392. This is the principle experimentally investigated in the author’s Cross-and Self-Fertilisation. {256} Origin, Ed. i. p. 268, vi. p. 398. {257} «Notes in original.» Mere difference of structure no guide to what will or will not cross. First step gained by races keeping apart. «It is not clear where these notes were meant to go.» {258} Origin, Ed. i. p. 272, vi. p. 404. {259} This section seems not to correspond closely with any in the Origin, Ed. i.; in some points it resembles pp. 15, 16, also the section on analogous variation in distinct species, Origin, Ed. i. p. 159, vi. p. 194. {260} The law of compensation is discussed in the Origin, Ed. i. p. 147, vi. p. 182. {261} «Note in original.» Boitard and Corbié on outer edging red in tail of bird,—so bars on wing, white or black or brown, or white edged with black or «illegible»: analogous to marks running through genera but with different colours. Tail coloured in pigeons. {262} «Note in original.» Oxalis and Gentian. «In Gentians blue, yellow and reddish colours occur. In Oxalis yellow, purple, violet and pink.» {263} This section corresponds roughly to that on Hybrids and Mongrels compared independently of their fertility, Origin, Ed. i. p. 272, vi. p. 403. The discussion on Gärtner’s views, given in the Origin, is here wanting. The brief mention of prepotency is common to them both. {264} See Animals and Plants, Ed. ii. vol. I. p. 435. The phenomenon of Telegony, supposed to be established by this and similar cases, is now generally discredited in consequence of Ewart’s experiments. {265} The section on p. 109 is an appendix to the summary. {266} I do not know the authority for this statement. {267} In the Origin no limit is placed to variation as far as I know. {268} «Note in original.» History of pigeons shows increase of peculiarities during last years. {269} Compare an obscure passage in the Essay of 1842, p. 14. {270} «Note in original.» Certainly «two pages in the MS.» ought to be here introduced, viz., difficulty in forming such organ, as eye, by selection. «In the Origin, Ed. i., a chapter on Difficulties on Theory follows that on Laws of Variation, and precedes that on Instinct: this was also the arrangement in the Essay of 1842; whereas in the present Essay Instinct follows Variation and precedes Difficulties.» {271} A similar proviso occurs in the chapter on instinct in Origin, Ed. i. p. 207, vi. p. 319. {272} The discussion occurs later in Chapter VII of the Origin, Ed. i. than in the present Essay, where moreover it is fuller in some respects. {273} In the margin occurs the name of Poeppig. In Var. under Dom., Ed. ii. vol. I. p. 28, the reference to Poeppig on the Cuban dogs contains no mention of the wildness of their offspring. {274} «Note in original.» Several authors. {275} In the margin “Hogg” occurs as authority for this fact. For the reference, see p. 17, note 4. {276} In the Origin, Ed. i., he speaks more decidedly against the belief that instincts are hereditary habits, see for instance pp. 209, 214, Ed. vi. pp. 321, 327. He allows, however, something to habit (p. 216). {277} A suggestion of Hering’s and S. Butler’s views on memory and inheritance. It is not, however, implied that Darwin was inclined to accept these opinions. {278} Lord Brougham’s Dissertations on Subjects of Science, etc., 1839, p. 27. {279} This case is more briefly given in the Origin, Ed. i. p. 213, vi. p. 326. The simile of the butterfly occurs there also. {280} “A little dose, as Pierre Huber expresses it, of judgment or reason, often comes into play.” Origin, Ed. i. p. 208, vi. p. 320. {281} In the margin is written “Retriever killing one bird.” This refers to the cases given in the Descent of Man, 2nd Ed. (in 1 vol.) p. 78, of a retriever being puzzled how to deal with a wounded and a dead bird, killed the former and carried both at once. This was the only known instance of her wilfully injuring game. {282} See Origin, Ed. i. p. 214, vi. p. 327. {283} «Note in original.» Give some definition of instinct, or at least give chief attributes. «In Origin, Ed. i. p. 207, vi. p. 319, Darwin refuses to define instinct.» The term instinct is often used in «a» sense which implies no more than that the animal does the action in question. Faculties and instincts may I think be imperfectly separated. The mole has the faculty of scratching burrows, and the instinct to apply it. The bird of passage has the faculty of finding its way and the instinct to put it in action at certain periods. It can hardly be said to have the faculty of knowing the time, for it can possess no means, without indeed it be some consciousness of passing sensations. Think over all habitual actions and see whether faculties and instincts can be separated. We have faculty of waking in the night, if an instinct prompted us to do something at certain hour of night or day. Savages finding their way. Wrangel’s account—probably a faculty inexplicable by the possessor. There are besides faculties “means,” as conversion of larvæ into neuters and queens. I think all this generally implied, anyhow useful. «This discussion, which does not occur in the Origin, is a first draft of that which follows in the text, p. 123.» {284} A short discussion of a similar kind occurs in the Origin, Ed. i. p. 211, vi. p. 324. {285} This sentence agrees with the MS., but is clearly in need of correction. {286} This corresponds to Origin, Ed. i. p. 212, vi. p. 325. {287} This discussion is interesting in differing from the corresponding section of the Origin, Ed. i. p. 216, vi. p. 330, to the end of the chapter. In the present Essay the subjects dealt with are nest-making instincts, including the egg-hatching habit of the Australian bush-turkey. The power of “shamming death.” “Faculty” in relation to instinct. The instinct of lapse of time, and of direction. Bees’ cells very briefly given. Birds feeding their young on food differing from their own natural food. In the Origin, Ed. i., the cases discussed are the instinct of laying eggs in other birds’ nests; the slave-making instinct in ants; the construction of the bee’s comb, very fully discussed. {288} The distinction between faculty and instinct corresponds in some degree to that between perception of a stimulus and a specific reaction. I imagine that the author would have said that the sensitiveness to light possessed by a plant is faculty, while instinct decides whether the plant curves to or from the source of illumination. {289} «Note in the original in an unknown handwriting.» At the time when corn was pitched in the market instead of sold by sample, the geese in the town fields of Newcastle «Staffordshire?» used to know market day and come in to pick up the corn spilt. {290} «Note in original.» Macculloch and others. {291} I can find no reference to the transandantes sheep in Darwin’s published work. He was possibly led to doubt the accuracy of the statement on which he relied. For the case of the sheep returning to their birth-place see p. 17, note 4. {292} Origin, Ed. i. p. 224, vi. p. 342. {293} This is an expansion of an obscure passage in the Essay of 1842, p. 19. {294} The difficulties discussed in the Origin, Ed. i. p. 171, vi. p. 207, are the rarity of transitional varieties, the origin of the tail of the giraffe; the otter-like polecat (Mustela vison); the flying habit of the bat; the penguin and the logger-headed duck; flying fish; the whale-like habit of the bear; the woodpecker; diving petrels; the eye; the swimming bladder; Cirripedes; neuter insects; electric organs. Of these, the polecat, the bat, the woodpecker, the eye, the swimming bladder are discussed in the present Essay, and in addition some botanical problems. {295} In the Origin, Ed. vi. p. 275, the author replies to Mivart’s criticisms (Genesis of Species, 1871), referring especially to that writer’s objection “that natural selection is incompetent to account for the incipient stages of useful structures.” {296} «The following sentence seems to have been intended for insertion here» “and that each eye throughout the animal kingdom is not only most useful, but perfect for its possessor.” {297} Origin, Ed. i. p. 190, vi. p. 230. {298} This is one of the most definite statements in the present Essay of the possible importance of sports or what would now be called mutations. As is well known the author afterwards doubted whether species could arise in this way. See Origin, Ed. v. p. 103, vi. p. 110, also Life and Letters, vol. iii. p. 107. {299} See Origin, Ed. i. p. 210, vi. p. 322, where the question is discussed for the case of instincts with a proviso that the same argument applies to structure. It is briefly stated in its general bearing in Origin, Ed. i. p. 87, vi. p. 106. {300} «Note in original.» No one will dispute that the gliding is most useful, probably necessary for the species in question. {301} «Note in original.» Is this the Galeopithecus? I forget. «Galeopithecus “or the flying Lemur” is mentioned in the corresponding discussion in the Origin, Ed. i. p. 181, vi. p. 217, as formerly placed among the bats. I do not know why it is described as partly aquatic in its habits.» {302} In the Origin, Ed. vi. p. 221, the author modified the statement that it never climbs trees; he also inserted a sentence quoting Mr Hudson to the effect that in other districts this woodpecker climbs trees and bores holes. See Mr Darwin’s paper, Zoolog. Soc. Proc., 1870, and Life and Letters, iii. p. 153. {303} Note by the late Alfred Newton. Richardson in Fauna Boreali-Americana, i. p. 49. {304} «Note in original.» See Richardson a far better case of a polecat animal «Mustela vison», which half-year is aquatic. «Mentioned in Origin, Ed. i. p. 179, vi. p. 216.» {305} In the Origin the division of the work into Parts I and II is omitted. In the MS. the chapters of Part II are numbered afresh, the present being Ch. I of Pt. II. I have thought it best to call it Ch. IV and there is evidence that Darwin had some thought of doing the same. It corresponds to Ch. IX of Origin, Ed. i., Ch. X in Ed. vi. {306} In the Essay of 1842 the author uses astronomy in the same manner as an illustration. In the Origin this does not occur; the reference to the action of secondary causes is more general, e.g. Ed. i. p. 488, vi. p. 668. {307} It is interesting to find the argument from sterility given so prominent a place. In a corresponding passage in the Origin, Ed. i. p. 480, vi. p. 659, it is more summarily treated. The author gives, as the chief bar to the acceptance of evolution, the fact that “we are always slow in admitting any great change of which we do not see the intermediate steps”; and goes on to quote Lyell on geological action. It will be remembered that the question of sterility remained a difficulty for Huxley. {308} Similar statements occur in the Essay of 1842, p. 24, note 1, and in the Origin, Ed. i. p. 299. {309} In the Origin, Ed. i. p. 280, vi. p. 414 he uses his newly-acquired knowledge of pigeons to illustrate this point. {310} Compare the Origin, Ed. i. p. 281, vi. p. 414. {311} Origin, Ed. i. p. 301, vi. p. 440. {312} Origin, Ed. i. p. 329, vi. p. 471. {313} The structure of the Pachyderm leg was a favourite with the author. It is discussed in the Essay of 1842, p. 48. In the present Essay the following sentence in the margin appears to refer to Pachyderms and Ruminants: “There can be no doubt, if we banish all fossils, existing groups stand more separate.” The following occurs between the lines “The earliest forms would be such as others could radiate from.” {314} Origin, Ed. i. p. 307, vi. p. 448. {315} «Pencil insertion by the author.» The parent-forms of Mollusca would probably differ greatly from all recent,—it is not directly that any one division of Mollusca would descend from first time unaltered, whilst others had become metamorphosed from it. {316} Origin, Ed. i. p. 291, vi. p. 426. {317} «Note in original.» Reflect on coming in of the Chalk, extending from Iceland to the Crimea. {318} Origin, Ed. i. p. 282, vi. p. 416. {319} Origin, Ed. i. pp. 288, 300, vi. pp. 422, 438. {320} «Note in original.» Neither highest or lowest fish (i.e. Myxina «?» or Lepidosiren) could be preserved in intelligible condition in fossils. {321} Origin, Ed. i. p. 290, vi. p. 425. {322} See Origin, Ed. i. p. 310, vi. p. 452 for Lyell's metaphor. I am indebted to Prof. Judd for pointing out that Darwin’s version of the metaphor is founded on the first edition of Lyell’s Principles, vol. I. and vol. III.; see the Essay of 1842, p. 27. {323} See More Letters, vol. I. pp. 344-7, for Darwin’s interest in the celebrated observations of Hilgendorf and Hyatt. {324} This corresponds partly to Origin, Ed. i. p. 294, vi. p. 431. {325} Origin, Ed. i. p. 299, vi. p. 437. {326} This chapter corresponds to ch. X of Origin, Ed. i., vi. ch. XI, “On the geological succession of organic beings.” {327} Origin, Ed. i. p. 312, vi. p. 453. {328} In the margin the author has written “Lonsdale.” This refers to W. Lonsdale’s paper “Notes on the age of the Limestone of South Devonshire,” Geolog. Soc. Trans., Series 2, vol. V. 1840, p. 721. According to Mr H. B. Woodward (History of the Geological Society of London, 1907, p. 107) “Lonsdale’s ‘important and original suggestion of the existence of an intermediary type of Palæozoic fossils, since called Devonian,’ led to a change which was then ‘the greatest ever made at one time in the classification of our English formations’.” Mr Woodward’s quotations are from Murchison and Buckland. {329} «Note in original.» Better begin with this. If species really, after catastrophes, created in showers over world, my theory false. «In the above passage the author is obviously close to his theory of divergence.» {330} Opposite to this passage the author has written “d’Archiac, Forbes, Lyell.” {331} This passage, for which the author gives as authorities the names of Lyell, Forbes and Ehrenberg, corresponds in part to the discussion beginning on p. 313 of Origin, Ed. i., vi. p. 454. {332} The author gives Falconer as his authority: see Origin, Ed. i. p. 313, vi. p. 454. {333} This corresponds approximately to Origin, Ed. i. p. 317, vi. p. 458. {334} The case of Trigonia, a great Secondary genus of shells surviving in a single species in the Australian seas, is given as an example in the Origin, Ed. i. p. 321, vi. p. 463. {335} This point, on which the author laid much stress, is discussed in the Origin, Ed. i. p. 319, vi. p. 461. {336} Origin, Ed. i. p. 72, vi. p. 89. {337} This case does not occur in the Origin, Ed. {338} An almost identical sentence occurs in the Origin, Ed. i. p. 320, vi. p. 462. {339} Origin, Ed. i. p. 316, vi. p. 457. {340} Chapters XI and XII in the Origin, Ed. i., vi. chs. XII and XIII (“On geographical distribution”) show signs of having been originally one, in the fact that one summary serves for both. The geological element is not separately treated there, nor is there a separate section on “how far these laws accord with the theory, &c.” In the MS. the author has here written in the margin “If same species appear at two spot at once, fatal to my theory.” See Origin, Ed. i. p. 352, vi. p. 499 {341} This division of the land into regions does not occur in the Origin, Ed. i. {342} Origin, Ed. i. p. 346, vi. p. 493. {343} Opposite this passage is written “not botanically,” in Sir J. D. Hooker’s hand. The word palms is underlined three times and followed by three exclamation marks. An explanatory note is added in the margin “singular paucity of palms and epiphytes in Trop. Africa compared with Trop. America and Ind. Or.” «=East Indies». {344} This partly corresponds to Origin, Ed. i. p. 337, vi. p. 483. {345} On the general importance of barriers, see Origin, Ed. i. p. 347, vi. p. 494. {346} Origin, Ed. i. p. 348, vi. p. 495. {347} «Note in original.» The same laws seem to govern distribution of species and genera, and individuals in time and space. «See Origin, Ed. i. p. 350, vi. p. 497, also a passage in the last chapter, p. 146.» {348} Origin, Ed. i. p. 404, vi. p. 559. {349} Origin, Ed. i. p. 349, vi. p. 496. {350} The case of the ostrich (Rhea) occurs in the Origin, Ed. i. p. 349, vi. p. 496. {351} «Note in original.» There is a hare in S. America,—so bad example. {352} See Origin, Ed. i. p. 349, vi. p. 497. {353} For the general problem of Oceanic Islands, see Origin, Ed. i. p. 388, vi. p. 541. {354} This is an illustration of the general theory of barriers (Origin, Ed. i. p. 347, vi. p. 494). At i. p. 391, vi. p. 544 the question is discussed from the point of view of means of transport. Between the lines, above the words “with that land,” the author wrote “Cause, formerly joined, no one doubts after Lyell.” {355} Origin, Ed. i. p. 390, vi. p. 543. {356} See Origin, Ed. i. p. 397, vi. p. 552. {357} The Cape de Verde and Galapagos Archipelagoes are compared in the Origin, Ed. i. p. 398, vi. p. 553. See also Journal of Researches, 1860, p. 393. {358} In the Origin, Ed. i. p. 390, a strong point is made of birds which immigrated “with facility and in a body” not having been modified. Thus the author accounts for the small percentage of peculiar “marine birds.” {359} “The affinities of the St Helena flora are strongly South African.” Hooker’s Lecture on Insular Floras in the Gardeners’ Chronicle, Jan. 1867. {360} It is impossible to make out the precise form which the author intended to give to this sentence, but the meaning is clear. {361} This is no doubt true, the flora of the Sandwich group however has marked American affinities. {362} See Origin, Ed. i. p. 365, vi. p. 515. The present discussion was written before the publication of Forbes’ celebrated paper on the same subject; see Life and Letters, vol. I. p. 88. {363} The apparent breakdown of the doctrine of barriers is slightly touched on in the Origin, Ed. i. p. 365, vi. p. 515. {364} In the Origin, Ed. i. p. 375, vi. p. 526, the author points out that on the mountains at the Cape of Good Hope “some few representative European forms are found, which have not been discovered in the inter-tropical parts of Africa.” {365} See Hooker’s Lecture on Insular Floras in the Gardeners’ Chronicle, Jan. 1867. {366} In the margin the author has written “(Forbes).” This may have been inserted at a date later than 1844, or it may refer to a work by Forbes earlier than his Alpine paper. {367} See Origin, Ed. i. p. 367, vi. p. 517. {368} «Note in original.» Perhaps vitality checked by cold and so prevented germinating. «On the carriage of seeds by icebergs, see Origin, Ed. i. p. 363, vi. p. 513.» {369} A note by the author gives “many authors” apparently as authority for this statement. {370} Opposite to this passage, in the margin, the author has written:—“too hypothetical.” {371} The Cordillera is described as supplying a great line of invasion in the Origin, Ed. i. p. 378. {372} This is an approximation to the author’s views on trans-tropical migration (Origin, Ed. i. pp. 376-8). See Thiselton-Dyer’s interesting discussion in Darwin and Modern Science, p. 304. {373} See Hooker’s Lecture on Insular Floras in the Gardeners’ Chronicle, Jan. 1867. {374} «Note by the author.» Similarity of flora of coral islands easily explained. {375} On centres of creation see Origin, Ed. i. p. 352, vi. p. 499. {376} In the Journal of Researches, Ed. 1860, p. 124, the distribution of the Bizcacha is described as limited by the river Uruguay. The case is not I think given in the Origin. {377} In the Origin, Ed. i. a special section (p. 356, vi. p. 504) is devoted to Means of Dispersal. The much greater prominence given to this subject in the Origin is partly accounted for by the author’s experiments being of later date, i.e. 1855 (Life and Letters, vol. II. p. 53). The carriage of fish by whirlwinds is given in the Origin, Ed. i. p. 384, vi. p. 536. {378} The case of islands serving as halting places is given in the Origin, Ed. i. p. 357, vi. p. 505. But here the evidence of this having occurred is supposed to be lost by the subsidence of the islands, not merely by the extinction of the species. {379} “We find no inexplicable cases of the same mammal inhabiting distant points of the world.” Origin, Ed. i. p. 352, vi. p. 500. See also Origin, Ed. i. p. 393, vi. p. 547. {380} «Note by the author.» Many authors. «See Origin, Ed. i. p. 394, vi. p. 547.» {381} Nutria is the Spanish for otter, and is now a synonym for Lutra. The otter on the Atlantic coast is distinguished by minute differences from the Pacific species. Both forms are said to take to the sea. In fact the case presents no especial difficulties. {382} In Origin, Ed. i. p. 394, vi. p. 548, bats are mentioned as an explicable exception to this statement. {383} This reference is doubtless to Mydaus, a badger-like animal from the mountains of Java and Sumatra (Wallace, Geographical Distribution, ii. p. 199). The instance does not occur in the Origin but the author remarks (Origin, Ed. i. p. 376, vi. p. 527) that cases, strictly analogous to the distribution of plants, occur among terrestrial mammals. {384} See Origin, Ed. i. p. 313, vi. p. 454. {385} The comparison between New Zealand and the Cape is given in the Origin, Ed. i. p. 389, vi. p. 542. {386} In a corresponding discussion in the Origin, Ed. i. p. 393, vi. p. 546, stress is laid on the distribution of Batrachians not of reptiles. {387} The whole argument is given—more briefly than here—in the Origin, Ed. i. p. 394, vi. p. 547. {388} See Origin, Ed i. p. 393, vi. p. 547. The discussion is much fuller in the present Essay. {389} See Origin, Ed. i. p. 339, vi. p. 485. {390} In the Origin, Ed. i. p. 339, vi. p. 485, which corresponds to this part of the present Essay, the author does not make a separate section for such cases as the occurrence of fossil Marsupials in Europe (Origin, Ed. i. p. 340, vi. p. 486) as he does in the present Essay; see the section on Changes in geographical distribution, p. 177. {391} “We can understand how it is that all the forms of life, ancient and recent, make together one grand system; for all are connected by generation.” Origin, Ed. i. p. 344, vi. p. 491. {392} The word hyæna is erased. There appear to be no fossil Hyænidæ in S. America. {393} See note 1, p. 175, also Origin, Ed. i. p. 340, vi. p. 486. {394} «Note by the author.» And see Eocene European mammals in N. America. {395} «Note by the author.» All this requires much verification. {396} This point seems to be less insisted on in the Origin. {397} Origin, Ed. i. p. 356, vi. p. 504. {398} «Note by the author.» D'Orbigny shows that this is not so. {399} This instance occurs in the Essay of 1842, p. 32, but not in the Origin; though the importance of isolation is discussed (Origin, Ed. i. p. 104, vi. p. 127). {400} The meaning of the words within parenthesis is obscure. {401} It is unusual to find the author speaking of the selection of sports rather than small variations. {402} This brief discussion is represented in the Origin, Ed. i. by a much fuller one (pp. 356, 383, vi. pp. 504, 535). See, however, the section in the present Essay, p. 168.[Link: Page 168] {403} On the formation of new stations, see Origin, Ed. i. p. 292, vi. p. 429. {404} Origin, Ed. i. pp. 390, 400, vi. pp. 543, 554. {405} In the MS. some of the species ... nourishing quality is doubtfully erased. It seems clear that he doubted whether such a problematical supply of food would be likely to cause variation. {406} At this time the author clearly put more faith in the importance of sport-like variation than in later years. {407} Origin, Ed. i. p. 398, vi. p. 553. {408} See Origin, Ed. i. p. 403, vi. p. 558, where the author speaks of Alpine humming birds, rodents, plants, &c. in S. America, all of strictly American forms. In the MS. the author has added between the lines “As world has been getting hotter, there has been radiation from high-lands,—old view?—curious; I presume Diluvian in origin.” {409} See the comparison between the Malay Archipelago and the probable former state of Europe, Origin, Ed. i. p. 299, vi. p. 438, also Origin, Ed. i. p. 292, vi. p. 429. {410} Origin, Ed. i. p. 349, vi. p. 496. The arrangement of the argument in the present Essay leads to repetition of statements made in the earlier part of the book: in the Origin this is avoided. {411} Origin, Ed. i. p. 389, vi. p. 542. {412} Origin, Ed. i. p. 393, vi. p. 547. {413} Origin, Ed. i. pp. 350, 404, vi. pp. 498, 559. {414} Origin, Ed. i. p. 352, vi. p. 500. {415} Origin, Ed. i. p. 313, vi. p. 454. {416} Origin, Ed. i. p. 341, vi. p. 487. {417} Origin, Ed. i. p. 396, vi. p. 549. {418} Origin, Ed. i. p. 340, vi. p. 486. {419} Origin, Ed. i. p. 299, vi. p. 437. {420} “Nature may almost be said to have guarded against the frequent discovery of her transitional or linking forms,” Origin, Ed. i. p. 292. A similar but not identical passage occurs in Origin, Ed. vi. p. 428. {421} Origin, Ed. i. p. 291, vi. p. 426. {422} Origin, Ed. i. p. 288, vi. p. 422. {423} Origin, Ed. i. p. 289, vi. p. 423. {424} Origin, Ed. i. p. 300, vi. p. 439. {425} Ch. XIII of the Origin, Ed. i., Ch. XIV Ed. vi. begins with a similar statement. In the present Essay the author adds a note:—“The obviousness of the fact (i.e. the natural grouping of organisms) alone prevents it being remarkable. It is scarcely explicable by creationist: groups of aquatic, of vegetable feeders and carnivorous, &c., might resemble each other; but why as it is. So with plants,—analogical resemblance thus accounted for. Must not here enter into details.” This argument is incorporated with the text in the Origin, Ed. i. {426} Origin, Ed. i. p. 411, vi. p. 566. {427} Origin, Ed. i. p. 316, vi. p. 457. {428} Origin, Ed. i. p. 321, vi. p. 463. {429} In the Origin, Ed. i. this preliminary matter is replaced (pp. 411, 412, vi. pp. 566, 567) by a discussion in which extinction is also treated, but chiefly from the point of view of the theory of divergence. {430} Origin, Ed. i. p. 414, vi. p. 570. {431} Origin, Ed. i. p. 414, vi. p. 570. {432} These instances occur with others in the Origin, Ed. i. p. 416, vi. p. 572. {433} Origin, Ed. i. p. 418, vi. p. 574. {434} Origin, Ed. i. pp. 419, 440, vi. pp. 575, 606. {435} Origin, Ed. i. pp. 418, 425, vi. pp. 574, 581. {436} Origin, Ed. i. p. 413, vi. p. 569. {437} Origin, Ed. i. pp. 419, 427, vi. pp. 575, 582. {438} This is discussed from the point of view of divergence in the Origin, Ed. i. pp. 420, 421, vi. pp. 576, 577. {439} «Footnote by the author.» I discuss this because if Quinarism true, I false. «The Quinary System is set forth in W. S. Macleay’s Horæ Entomologicæ, 1821.» {440} In the corresponding passage in the Origin, Ed. i. p. 430, vi. p. 591, the term general is used in place of generic, and seems a better expression. In the margin the author gives Waterhouse as his authority. {441} Origin, Ed. i. p. 430, vi. p. 591. {442} In a corresponding passage in the Origin, Ed. i. p. 423, vi. p. 579, the author makes use of his knowledge of pigeons. The pseudo-genera among dogs are discussed in Var. under Dom., Ed. ii. vol. I. p. 38. {443} Origin, Ed. i. pp. 419, 427, vi. pp. 575, 582. {444} Origin, Ed. i. pp. 423, 427, vi. pp. 579, 583. {445} Origin, Ed. i. p. 423, vi. p. 579. {446} A general statement of the influence of conditions on variation occurs in the Origin, Ed. i. pp. 131-3, vi. pp. 164-5. {447} Origin, Ed. i. p. 423, vi. p. 579. In the margin Marshall is given as the authority. {448} Origin, Ed. i. p. 423, vi. p. 579. {449} The discussion here following corresponds more or less to the Origin, Ed. i. pp. 411, 412, vi. pp. 566, 567; although the doctrine of divergence is not mentioned in this Essay (as it is in the Origin) yet the present section seems to me a distinct approximation to it. {450} The author probably intended to write “groups separated by chasms.” {451} A similar discussion occurs in the Origin, Ed. i. p. 427, vi. p. 582. {452} Puffinuria berardi, see Origin, Ed. i. p. 184, vi. p. 221. {453} Origin, Ed. i. p. 430, vi. p. 591. {454} Origin, Ed. i. p. 434, vi. p. 595. Ch. VIII corresponds to a section of Ch. XIII in the Origin, Ed. i. {455} Origin, Ed. i. p. 434, vi. p. 596. In the Origin, Ed. i. these examples occur under the heading Morphology; the author does not there draw much distinction between this heading and that of Unity of Type. {456} See Origin, Ed. i. p. 436, vi. p. 599, where the parts of the flower, the jaws and palpi of Crustaceans and the vertebrate skull are given as examples. {457} The author here brings Unity of Type and Morphology together. {458} The solid-hoofed pigs mentioned in Var. under Dom., Ed. ii. vol. II. p. 424 are not Lincolnshire pigs. For other cases see Bateson, Materials for the Study of Variation, 1894, pp. 387-90. {459} In the margin C. Bell is given as authority, apparently for the statement about Plesiosaurus. See Origin, Ed. i. p. 436, vi. p. 598, where the author speaks of the “general pattern” being obscured in “extinct gigantic sea lizards.” In the same place the suctorial Entomostraca are added as examples of the difficulty of recognising the type. {460} Origin, Ed. i. p. 438, vi. p. 602. {461} Origin, Ed. i. p. 439, vi. p. 604. {462} The uselessness of the branchial arches in mammalia is insisted on in the Origin, Ed. i. p. 440, vi. p. 606. Also the uselessness of the spots on the young blackbird and the stripes of the lion-whelp, cases which do not occur in the present Essay. {463} In the Origin, Ed. i. pp. 442, 448, vi. pp. 608, 614 it is pointed out that in some cases the young form resembles the adult, e.g. in spiders; again, that in the Aphis there is no “worm-like stage” of development. {464} In the Origin, Ed. i. p. 449, vi. p. 618, the author speaks doubtfully about the recapitulation theory. {465} This corresponds to the Origin, Ed. i. p. 441, vi. p. 607, where, however, the example is taken from the Cirripedes. {466} Origin, Ed. i. p. 449, vi. p. 617. {467} This corresponds to the Origin, Ed. i. pp. 443-4, vi. p. 610: the “feline animal” is not used to illustrate the generalisation, but is so used in the Essay of 1842, p. 42. {468} Origin, Ed. i. p. 447, vi. p. 613. {469} In the margin is written “Get young pigeons”; this was afterwards done, and the results are given in the Origin, Ed. i. p. 445, vi. p. 612. {470} In the Origin, Ed. i. the corresponding passages are at pp. 8, 13, 443, vi. pp. 8, 15, 610. In the Origin, Ed. i. I have not found a passage so striking as that which occurs a few lines lower “that the germinal vesicle is impressed with some power which is wonderfully preserved, &c.” In the Origin this preservation is rather taken for granted. {471} «In the margin is written» Aborted organs show, perhaps, something about period «at» which changes supervene in embryo. {472} See p. 42, note 5. {473} The evidence is given in Var. under Dom., I. p. 316. {474} Origin, Ed. i. p. 444, vi. p. 610. {475} In Var. under Dom., Ed. ii. vol. I. p. 295, such eggs are said to be laid early in each season by the black Labrador duck. In the next sentence in the text the author does not distinguish the characters of the vegetable capsule from those of the ovum. {476} This seems to me to be more strongly stated here than in the Origin, Ed. i. {477} Origin, Ed. i. p. 444, vi. p. 611. {478} Origin, Ed. i. p. 441, vi. p. 607. {479} Compare Origin, Ed. i. p. 419, vi. p. 575. {480} «Note in original.» Scarcely possible to distinguish between non-development and retrograde development. {481} See p. 42, where the same illustration is used. {482} Var. under Dom., Ed. ii. vol. I. p. 452. {483} Origin, Ed. i. p. 441, vi. p. 607. {484} Origin, Ed. i. p. 449, vi. p. 617. {485} Origin, Ed. i. p. 449, vi. p. 618. {486} In the Origin, Ed. i. p. 450, vi. p. 619, the author does not lay stress on any distinction in meaning between the terms abortive and rudimentary organs. {487} Origin, Ed. i. p. 450, vi. p. 619. {488} Ibid. {489} This argument occurs in Origin, Ed. i. p. 451, vi. p. 619. {490} Origin, Ed. i. p. 451, vi. p. 619, on male mammæ. In the Origin he speaks certainly of the abortive mammæ of the cow giving milk,—a point which is here queried. {491} Origin, Ed. i. p. 451, vi. p. 620. {492} The case of rudimentary organs adapted to new purposes is discussed in the Origin, Ed. i. p. 451, vi. p. 620. {493} This is here stated on the authority of Sprengel; see also Origin, Ed. i. p. 452, vi. p. 621. {494} Origin, Ed. i. p. 455, vi. p. 627. In the margin R. Brown's name is given apparently as the authority for the fact. {495} Origin, Ed. i. p. 455, vi. p. 626. {496} Origin, Ed. i. p. 454, vi. p. 625. {497} In the Origin, Ed. i. p. 454, vi. p. 625, the author in referring to semi-monstrous variations adds “But I doubt whether any of these cases throw light on the origin of rudimentary organs in a state of nature.” In 1844 he was clearly more inclined to an opposite opinion. {498} Origin, Ed. i. p. 454, vi. p. 625. {499} See Origin, Ed. i. p. 454, vi. p. 625. The author there discusses monstrosities in relation to rudimentary organs, and comes to the conclusion that disuse is of more importance, giving as a reason his doubt “whether species under nature ever undergo abrupt changes.” It seems to me that in the Origin he gives more weight to the “Lamarckian factor” than he did in 1844. Huxley took the opposite view, see the Introduction. {500} Origin, Ed. i. p. 455, vi. p. 627. {501} Origin, Ed. i. p. 11, vi. p. 13, where drooping-ears of domestic animals are also given. {502} Origin, Ed. i. p. 137, vi. p. 170. {503} These words seem to have been inserted as an afterthought. {504} Origin, Ed. i. p. 444, vi. p. 611. {505} This and similar cases occur in the Origin, Ed. i. p. 452, vi. p. 621. {506} The metaphor of the dishes is given in the Essay of 1842, p. 47, note 3. {507} Compare however Darwin’s later view:—“The possibility of making distinct races by crossing has been greatly exaggerated,” Origin, Ed. i. p. 20, vi. p. 23. The author’s change of opinion was no doubt partly due to his experience in breeding pigeons. {508} In the Origin, Ed. i. p. 469, vi. p. 644, Darwin makes a strong statement to this effect. {509} “A grain in the balance will determine which individual shall live and which shall die,” Origin, Ed. i. p. 467, vi. p. 642. A similar statement occurs in the 1842 Essay, p. 8, note 3. {510} Thus according to the author what is now known as orthogenesis is due to selection. {511} Part II begins with Ch. IV. See the Introduction, where the absence of division into two parts (in the Origin) is discussed. {512} In the recapitulation in the last chapter of the Origin, Ed. i. p. 475, vi. p. 651, the author does not insist on this point as the weightiest difficulty, though he does so in Ed. i. p. 299. It is possible that he had come to think less of the difficulty in question: this was certainly the case when he wrote the 6th edition, see p. 438. {513} «The following words:» The fauna changes singly «were inserted by the author, apparently to replace a doubtful erasure». {514} This question forms the subject of what is practically a section of the final chapter of the Origin (Ed. i. p. 480, vi. p. 657). {515} Origin, Ed. i. p. 481, vi. p. 659. {516} The discussion on the three species of Rhinoceros which also occurs in the Essay of 1842, p. 48, was omitted in Ch. XIV of the Origin, Ed. i. {517} This corresponds to a paragraph in the Origin, Ed. i. p. 483, vi. p. 662, where it is assumed that animals have descended “from at most only four or five progenitors, and plants from an equal or lesser number.” In the Origin, however, the author goes on, Ed. i. p. 484, vi. p. 663: “Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype.” {518} This sentence corresponds, not to the final section of the Origin, Ed. i. p. 484, vi. p. 664, but rather to the opening words of the section already referred to (Origin, Ed. i. p. 480, vi. p. 657). {519} This simile occurs in the Essay of 1842, p. 50, and in the Origin, Ed. i. p. 485, vi. p. 665, i.e. in the final section of Ch. XIV (vi. Ch. XV). In the MS. there is some erasure in pencil of which I have taken no notice. {520} An almost identical sentence occurs in the Origin, Ed. i. p. 487, vi. p. 667. The fine prophecy (in the Origin, Ed. i. p. 486, vi. p. 666) on “the almost untrodden field of inquiry” is wanting in the present Essay. {521} See the last paragraph on p. 488 of the Origin, Ed. i., vi. p. 668. {522} A passage corresponding to this occurs in the sketch of 1842, p. 51, but not in the last chapter of the Origin. {523} This sentence occurs in an almost identical form in the Origin, Ed. i. p. 490, vi. p. 669. It will be noted that man is not named though clearly referred to. Elsewhere (Origin, Ed. i. p. 488) the author is bolder and writes “Light will be thrown on the origin of man and his history.” In Ed. vi. p. 668, he writes “Much light &c.” {524} For the history of this sentence (with which the Origin of Species closes) see the Essay of 1842, p. 52, note 2: also the concluding pages of the Introduction. {525} These four words are added in pencil between the lines.