hunting certain objects and manner of doing so,--sheep-dog. These are shown clearly by crossing and their analogy with true instinct thus shown,--retriever. Do not know objects for which they do it. Lord Brougham's definition{90}. Origin partly habit, but the amount necessarily unknown, partly selection. Young pointers pointing stones and sheep--tumbling pigeons--sheep{91} going back to place where born.
Instinct aided by reason, as in the taylor-bird{92}. Taught by parents, cows choosing food, birds singing. Instincts vary in wild state (birds get wilder) often lost{93}; more perfect,--nest without roof. These facts [only clear way] show how incomprehensibly brain has power of transmitting intellectual operations.
{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 {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.
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.
Faculties{94} distinct from true instincts,--finding [way]. It must I think be admitted that habits whether congenital or acquired by practice [sometimes] often become inherited{95}; instincts, influence, equally with structure, the preservation of animals; therefore selection must, with changing conditions tend to modify the inherited habits of animals.
If this be admitted it will be found _possible_ that many of the strangest instincts may be thus acquired. I may observe, without attempting definition, that an inherited habit or trick (trick because may be born) fulfils closely what we mean by instinct. A habit is often performed unconsciously, the strangest habits become associated, d^o.
tricks, going in certain spots &c. &c., even against will, is excited by external agencies, and looks not to the end,--a person playing a pianoforte. If such a habit were transmitted it would make a marvellous instinct. Let us consider some of the most difficult cases of instincts, whether they could be _possibly_ acquired. I do not say _probably_, for that belongs to our 3rd Part{96}, I beg this may be remembered, nor do I mean to attempt to show exact method. I want only to show that whole theory ought not at once to be rejected on this score.
{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.
Every instinct must, by my theory, have been acquired gradually by slight changes <illegible> of former instinct, each change being useful to its then species. Shamming death struck me at first as remarkable objection. I found none really sham death{97}, and that there is gradation; now no one doubts that those insects which do it either more or less, do it for some good, if then any species was led to do it more, and then <?> escaped &c. &c.
{97} The meaning is that the attitude assumed in _shamming_ is not accurately like that of death.
Take migratory instincts, faculty distinct from instinct, animals have notion of time,--like savages. Ordinary finding way by memory, but how does savage find way across country,--as incomprehensible to us, as animal to them,--geological changes,--fishes in river,--case of sheep in Spain{98}. Architectural instincts,--a manufacturer's employee in making single articles extraordinary skill,--often said seem to make it almost <illegible>, child born with such a notion of playing{99},--we can fancy tailoring acquired in same perfection,--mixture of reason,--water-ouzel,--taylor-bird,--gradation of simple nest to most complicated.
{98} This refers to the _transandantes_ sheep mentioned in the MS.
of 1844, as having acquired a migratory instinct.
pseudo-instinctive skill in piano-playing is mentioned. See _Phil.
Bees again, distinction of faculty,--how they make a hexagon,--Waterhouse's theory{100},--the impulse to use whatever faculty they possess,--the taylor-bird has the faculty of sewing with beak, instinct impels him to do it.
{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.
Last case of parent feeding young with different food (take case of Galapagos birds, gradation from Hawfinch to Sylvia) selection and habit might lead old birds to vary taste <?> and form, leaving their instinct of feeding their young with same food{101},--or I see no difficulty in parents being forced or induced to vary the food brought, and selection adapting the young ones to it, and thus by degree any amount of diversity might be arrived at. Although we can never hope to see the course revealed by which different instincts have been acquired, for we have only present animals (not well known) to judge of the course of gradation, yet once grant the principle of habits, whether congenital or acquired by experience, being inherited and I can see no limit to the [amount of variation] extraordinariness <?> of the habits thus acquired.
{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.
_Summing up this Division._ If variation be admitted to occur occasionally in some wild animals, and how can we doubt it, when we see [all] thousands <of> organisms, for whatever use taken by man, do vary.
If we admit such variations tend to be hereditary, and how can we doubt it when we <remember> resemblances of features and character,--disease and monstrosities inherited and endless races produced (1200 cabbages).
If we admit selection is steadily at work, and who will doubt it, when he considers amount of food on an average fixed and reproductive powers act in geometrical ratio. If we admit that external conditions vary, as all geology proclaims, they have done and are now doing,--then, if no law of nature be opposed, there must occasionally be formed races, [slightly] differing from the parent races. So then any such law{102}, none is known, but in all works it is assumed, in <?> flat contradiction to all known facts, that the amount of possible variation is soon acquired. Are not all the most varied species, the oldest domesticated: who <would> think that horses or corn could be produced? Take dahlia and potato, who will pretend in 5000 years{103} <that great changes might not be effected>: perfectly adapted to conditions and then again brought into varying conditions. Think what has been done in few last years, look at pigeons, and cattle. With the amount of food man can produce he may have arrived at limit of fatness or size, or thickness of wool <?>, but these are the most trivial points, but even in these I conclude it is impossible to say we know the limit of variation. And therefore with the [adapting] selecting power of nature, infinitely wise compared to those of man, <I conclude> that it is impossible to say we know the limit of races, which would be true <to their> kind; if of different constitutions would probably be infertile one with another, and which might be adapted in the most singular and admirable manner, according to their wants, to external nature and to other surrounding organisms,--such races would be species. But is there any evidence <that> species <have> been thus produced, this is a question wholly independent of all previous points, and which on examination of the kingdom of nature <we> ought to answer one way or another.
{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.
described as showing sensitiveness to conditions in 1841. All the varieties of the _Dahlia_ are said to have arisen since 1804 PART II{104}.
{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.
I may premise, that according to the view ordinarily received, the myriads of organisms peopling this world have been created by so many distinct acts of creation. As we know nothing of the <illegible> will of a Creator,--we can see no reason why there should exist any relation between the organisms thus created; or again, they might be created according to any scheme. But it would be marvellous if this scheme should be the same as would result from the descent of groups of organisms from [certain] the same parents, according to the circumstances, just attempted to be developed.
With equal probability did old cosmogonists say fossils were created, as we now see them, with a false resemblance to living beings{105}; what would the Astronomer say to the doctrine that the planets moved <not> according to the law of gravitation, but from the Creator having willed each separate planet to move in its particular orbit? I believe such a proposition (if we remove all prejudices) would be as legitimate as to admit that certain groups of living and extinct organisms, in their distribution, in their structure and in their relations one to another and to external conditions, agreed with the theory and showed signs of common descent, and yet were created distinct. As long as it was thought impossible that organisms should vary, or should anyhow become adapted to other organisms in a complicated manner, and yet be separated from them by an impassable barrier of sterility{106}, it was justifiable, even with some appearance in favour of a common descent, to admit distinct creation according to the will of an Omniscient Creator; or, for it is the same thing, to say with Whewell that the beginnings of all things surpass the comprehension of man. In the former sections I have endeavoured to show that such variation or specification is not impossible, nay, in many points of view is absolutely probable. What then is the evidence in favour of it and what the evidence against it.
With our imperfect knowledge of past ages [surely there will be some] it would be strange if the imperfection did not create some unfavourable evidence.
{105} This passage corresponds roughly to the conclusion of the {106} A similar passage occurs in the conclusion of the _Origin_, Give sketch of the Past,--beginning with facts appearing hostile under present knowledge,--then proceed to geograph. distribution,--order of Our theory requires a very gradual introduction of new forms{107}, and extermination of the old (to which we shall revert). The extermination of old may sometimes be rapid, but never the introduction. In the groups descended from common parent, our theory requires a perfect gradation not differing more than breed<s> of cattle, or potatoes, or cabbages in forms. I do not mean that a graduated series of animals must have existed, intermediate between horse, mouse, tapir{108}, elephant [or fowl and peacock], but that these must have had a common parent, and between horse and this <?> parent &c., &c., but the common parent may possibly have differed more from either than the two do now from each other. Now what evidence of this is there? So perfect gradation in some departments, that some naturalists have thought that in some large divisions, if all existing forms were collected, a near approach to perfect gradation would be made. But such a notion is preposterous with respect to all, but evidently so with mammals. Other naturalists have thought this would be so if all the specimens entombed in the strata were collected{109}. I conceive there is no probability whatever of this; nevertheless it is certain all the numerous fossil forms fall in<to>, as Buckland remarks, _not_ present classes, families and genera, they fall between them: so is it with new discoveries of existing forms.
Most ancient fossils, that is most separated <by> space of time, are most apt to fall between the classes--(but organisms from those countries most separated by space also fall between the classes <_e.g._> Ornithorhyncus?). As far as geological discoveries <go> they tend towards such gradation{110}. Illustrate it with net. Toxodon,--tibia and fibula,--dog and otter,--but so utterly improbable is <it>, in _ex. gr._ Pachydermata, to compose series as perfect as cattle, that if, as many geologists seem to infer, each separate formation presents even an approach to a consecutive history, my theory must be given up. Even if it were consecutive, it would only collect series of one district in our present state of knowledge; but what probability is there that any one formation during the _immense_ period which has elapsed during each period will _generally_ present a consecutive history. [Compare number living at one period to fossils preserved--look at enormous periods of time.]
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, {Note 161} of this Essay.
Referring only to marine animals, which are obviously most likely to be preserved, they must live where <?> sediment (of a kind favourable for preservation, not sand and pebble){111} is depositing quickly and over large area and must be thickly capped, <illegible> littoral deposits: for otherwise denudation <will destroy them>,--they must live in a shallow space which sediment will tend to fill up,--as movement is <in?> progress if soon brought <?> up <?> subject to denudation,--[if] as during subsidence favourable, accords with facts of European deposits{112}, but subsidence apt to destroy agents which produce sediment{113}.
{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.
I believe safely inferred <that> groups of marine <?> fossils only preserved for future ages where sediment goes on long <and> continuous<ly> and with rapid but not too rapid deposition in <an> area of subsidence. In how few places in any one region like Europe will <?> these contingencies be going on? Hence <?> in past ages mere [gaps] pages preserved{114}. Lyell's doctrine carried to extreme,--we shall understand difficulty if it be asked:--what chance of series of gradation between cattle by <illegible> at age <illegible> as far back as Miocene{115}? We know then cattle existed. Compare number of living,--immense duration of each period,--fewness of fossils.
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."
This only refers to consecutiveness of history of organisms of each formation.
The foregoing argument will show firstly, that formations are distinct merely from want of fossils <of intermediate beds>, and secondly, that each formation is full of gaps, has been advanced to account for _fewness_ of _preserved_ organisms compared to what have lived on the world. The very same argument explains why in older formations the organisms appear to come on and disappear suddenly,--but in [later] tertiary not quite suddenly{116}, in later tertiary gradually,--becoming rare and disappearing,--some have disappeared within man's time. It is obvious that our theory requires gradual and nearly uniform introduction, possibly more sudden extermination,--subsidence of continent of Australia &c., &c.
{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 Our theory requires that the first form which existed of each of the great divisions would present points intermediate between existing ones, but immensely different. Most geologists believe Silurian{117} fossils are those which first existed in the whole world, not those which have chanced to be the oldest not destroyed,--or the first which existed in profoundly deep seas in progress of conversion from sea to land: if they are first they <? we> give up. Not so Hutton or Lyell: if first reptile{118} of Red Sandstone <?> really was first which existed: if Pachyderm{119} of Paris was first which existed: fish of Devonian: dragon fly of Lias: for we cannot suppose them the progenitors: they agree too closely with existing divisions. But geologists consider Europe as <?> a passage from sea to island <?> to continent (except Wealden, see Lyell). These animals therefore, I consider then mere introduction <?> from continents long since submerged.
{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.
Finally, if views of some geologists be correct, my theory must be given up. [Lyell's views, as far as they go, are in _favour_, but they go so little in favour, and so much more is required, that it may <be> viewed as objection.] If geology present us with mere pages in chapters, towards end of <a> history, formed by tearing out bundles of leaves, and each page illustrating merely a small portion of the organisms of that time, the facts accord perfectly with my theory{120}.
{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 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.
_Extermination._ We have seen that in later periods the organisms have disappeared by degrees and [perhaps] probably by degrees in earlier, and I have said our theory requires it. As many naturalists seem to think extermination a most mysterious circumstance{121} and call in astonishing agencies, it is well to recall what we have shown concerning the struggle of nature. An exterminating agency is at work with every organism: we scarcely see it: if robins would increase to thousands in ten years how severe must the process be. How imperceptible a small increase: fossils become rare: possibly sudden extermination as Australia, but as present means very slow and many means of escape, I shall doubt very sudden exterminations. Who can explain why some species abound more,--why does marsh titmouse, or ring-ouzel, now little change,--why is one sea-slug rare and another common on our coasts,--why one species of Rhinoceros more than another,--why is <illegible> tiger of India so rare? Curious and general sources of error, the place of an organism is instantly filled up.
{121} On rarity and extinction see _Origin_, Ed. i. pp. 109, 319, vi. pp. 133, 461.
We know state of earth has changed, and as earthquakes and tides go on, the state must change,--many geologists believe a slow gradual cooling.
Now let us see in accordance with principles of [variation] specification explained in Sect. II. how species would probably be introduced and how such results accord with what is known.
The first fact geology proclaims is immense number of extinct forms, and new appearances. Tertiary strata leads to belief, that forms gradually become rare and disappear and are gradually supplied by others. We see some forms now becoming rare and disappearing, we know of no sudden creation: in older periods the forms _appear_ to come in suddenly, scene shifts: but even here Devonian, Permian &c. [keep on supplying new links in chain]--Genera and higher forms come on and disappear, in same way leaving a species on one or more stages below that in which the form abounded.
§ VI. Let us consider the absolute state of distribution of organisms of earth's face.
Referring chiefly, but not exclusively (from difficulty of transport, fewness, and the distinct characteristics of groups) to Mammalia; and first considering the three or four main [regions] divisions; North America, Europe, Asia, including greater part of E. Indian Archipelago and Africa are intimately allied. Africa most distinct, especially most southern parts. And the Arctic regions, which unite N. America, Asia and Europe, only separated (if we travel one way by Behring's St.) by a narrow strait, is most intimately allied, indeed forms but one restricted group. Next comes S. America,--then Australia, Madagascar (and some small islands which stand very remote from the land). Looking at these main divisions separately, the organisms vary according to changes in condition{122} of different parts. But besides this, barriers of every kind seem to separate regions in a greater degree than proportionally to the difference of climates on each side. Thus great chains of mountains, spaces of sea between islands and continents, even great rivers and deserts. In fact the amount <of> difference in the organisms bears a certain, but not invariable relation to the amount of physical difficulties to transit{123}.
{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?"
There are some curious exceptions, namely, similarity of fauna of mountains of Europe and N. America and Lapland. Other cases just <the> reverse, mountains of eastern S. America, Altai <?>, S. India <?>{124}: mountain summits of islands often eminently peculiar. Fauna generally of some islands, even when close, very dissimilar, in others very similar.
[I am here led to observe one or more centres of creation{125}.]
{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 The simple geologist can explain many of the foregoing cases of distribution. Subsidence of a continent in which free means of dispersal, would drive the lowland plants up to the mountains, now converted into islands, and the semi-alpine plants would take place of alpine, and alpine be destroyed, if mountains originally were not of great height. So we may see, during gradual changes{126} of climate on a continent, the propagation of species would vary and adapt themselves to small changes causing much extermination{127}. The mountains of Europe were quite lately covered with ice, and the lowlands probably partaking of the Arctic climate and Fauna. Then as climate changed, arctic fauna would take place of ice, and an inundation of plants from different temperate countries <would> seize the lowlands, leaving islands of arctic forms. But if this had happened on an island, whence could the new forms have come,--here the geologist calls in creationists. If island formed, the geologist will suggest <that> many of the forms might have been borne from nearest land, but if peculiar, he calls in creationist,--as such island rises in height &c., he still more calls in creation. The creationist tells one, on a <illegible> spot the American spirit of creation makes _Orpheus_ and _Tyrannus_ and American doves, and in accordance with past and extinct forms, but no persistent relation between areas and distribution, Geologico-Geograph.-Distribution.
{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 {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.
Now according to analogy of domesticated animals let us see what would result. Let us take case of farmer on Pampas, where everything approaches nearer to state of nature. He works on organisms having strong tendency to vary: and he knows <that the> only way to make a distinct breed is to select and separate. It would be useless to separate the best bulls and pair with best cows if their offspring run loose and bred with the other herds, and tendency to reversion not counteracted; he would endeavour therefore to get his cows on islands and then commence his work of selection. If several farmers in different _rincons_{128} were to set to work, especially if with different objects, several breeds would soon be produced. So would it be with horticulturist and so history of every plant shows; the number of varieties{129} increase in proportion to care bestowed on their selection and, with crossing plants, separation. Now, according to this analogy, change of external conditions, and isolation either by chance landing <of> a form on an island, or subsidence dividing a continent, or great chain of mountains, and the number of individuals not being numerous will best favour variation and selection{130}. No doubt change could be effected in same country without any barrier by long continued selection on one species: even in case of a plant not capable of crossing would easier get possession and solely occupy an island{131}.
Now we can at once see that <if> two parts of a continent isolated, new species thus generated in them, would have closest affinities, like cattle in counties of England: if barrier afterwards destroyed one species might destroy the other or both keep their ground. So if island formed near continent, let it be ever so different, that continent would supply inhabitants, and new species (like the old) would be allied with that continent. An island generally very different soil and climate, and number and order of inhabitants supplied by chance, no point so favourable for generation of new species{132},--especially the mountains, hence, so it is. As isolated mountains formed in a plain country (if such happens) is an island. As other islands formed, the old species would spread and thus extend and the fauna of distant island might ultimately meet and a continent formed between them. No one doubts continents formed by repeated elevations and depressions{133}. In looking backwards, but not so far that all geographical boundaries are destroyed, we can thus at once see why existing forms are related to the extinct in the same manner as existing ones are in some part of existing continent. By chance we might even have one or two absolute parent fossils.
{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."