Besides selection by death, in bisexual animals «illegible»
the selection in time of fullest vigour, namely struggle of males; even
in animals which pair there seems a surplus «?» and a
battle, possibly as in man more males produced than females, struggle of
war or charms{63}.
Hence that male which at that time is in fullest vigour, or best armed
with arms or ornaments of its species, will gain in hundreds of
generations some small advantage and transmit such characters to its
offspring. So in female rearing its young, the most vigorous and skilful
and industrious, «whose» instincts «are»
best developed, will rear more young, probably possessing her good
qualities, and a greater number will thus «be» prepared for
the struggle of nature. Compared to man using a male alone of good
breed. This latter section only of limited application, applies to
variation of [specific] sexual characters. Introduce here contrast with
Lamarck,—absurdity of habit, or chance?? or external conditions,
making a woodpecker adapted to tree{64}.
Before considering difficulties of theory of selection let us consider character of the races produced, as now explained, by nature. Conditions have varied slowly and the organisms best adapted in their whole course of life to the changed conditions have always been selected,—man selects small dog and afterwards gives it profusion of food,—selects a long-backed and short-legged breed and gives it no particular exercise to suit this function &c. &c. In ordinary cases nature has not allowed her race to be contaminated with a cross of another race, and agriculturists know how difficult they find always to prevent this,—effect would be trueness. This character and sterility when crossed, and generally a greater amount of difference, are two main features, which distinguish domestic races from species.
[Sterility not universal admitted by all{65}.
Gladiolus, Crinum, Calceolaria{66}
must be species if there be such a thing. Races of dogs and oxen: but
certainly very general; indeed a gradation of sterility most perfect{67}
very general. Some nearest species will not cross (crocus, some heath
«?»), some genera cross readily (fowls{68}
and grouse, peacock &c.). Hybrids no ways monstrous quite perfect
except secretions{69}
hence even the mule has bred,—character of sterility, especially a
few years ago «?» thought very much more universal than it
now is, has been thought the distinguishing character; indeed it is
obvious if all forms freely crossed, nature would be a chaos. But the
very gradation of the character, even if it always existed in some
degree which it does not, renders it impossible as marks «?»
those «?» suppose distinct as species{70}].
Will analogy throw any light
on the fact of the supposed races of nature being sterile, though none
of the domestic ones are? Mr Herbert «and» Koelreuter have
shown external differences will not guide one in knowing whether hybrids
will be fertile or not, but the chief circumstance is constitutional
differences{71},
such as being adapted to different climate or soil, differences which
[must] probably affect the whole body of the organism and not any one
part. Now wild animals, taken out of their natural conditions, seldom
breed. I do not refer to shows or to Zoological Societies where many
animals unite, but «do not?» breed, and others will never
unite, but to wild animals caught and kept quite tame left loose and
well fed about houses and living many years. Hybrids produced almost as
readily as pure breds. St Hilaire great distinction of tame and
domestic,—elephants,—ferrets{72}.
Reproductive organs not subject to disease in Zoological Garden.
Dissection and microscope show that hybrid is in exactly same condition
as another animal in the intervals of breeding season, or those animals
which taken wild and not bred in domesticity, remain without breeding
their whole lives. It should be observed that so far from domesticity
being unfavourable in itself «it» makes more fertile: [when
animal is domesticated and breeds, productive power increased from more
food and selection of fertile races]. As far as animals go might be
thought «an» effect on their mind and a special case.
But turning to plants we find same class of facts. I do not refer to
seeds not ripening, perhaps the commonest
cause, but to plants not setting, which either is owing to some
imperfection of ovule or pollen. Lindley says sterility is the [curse]
bane of all propagators,—Linnæus about alpine plants.
American bog plants,—pollen in exactly same state as in
hybrids,—same in geraniums. Persian and Chinese{73}
lilac will not seed in Italy and England. Probably double plants and all
fruits owe their developed parts primarily «?» to sterility
and extra food thus «?» applied{74}.
There is here gradation «in» sterility and then parts, like
diseases, are transmitted hereditarily. We cannot assign any cause why
the Pontic Azalea produces plenty of pollen and not American{75},
why common lilac seeds and not Persian, we see no difference in
healthiness. We know not on what circumstances these facts depend, why
ferret breeds, and cheetah{76},
elephant and pig in India will not.
Now in crossing it is certain every peculiarity in form and constitution
is transmitted: an alpine plant transmits its alpine tendency to its
offspring, an American plant its American-bog constitution, and
«with» animals, those peculiarities, on which{77}
when placed out of their natural conditions they are incapable of
breeding; and moreover they transmit every part of their constitution,
their
respiration, their pulse, their instinct, which are all suddenly
modified, can it be wondered at that they are incapable of breeding? I
think it may be truly said it would be more wonderful if they did. But
it may be asked why have not the recognised varieties, supposed to have
been produced through the means of man, [not refused to breed] have all
bred{78}.
Variation depends on change of condition and selection{79},
as far as man’s systematic or unsystematic selection
«has» gone; he takes external form, has little power from
ignorance over internal invisible constitutional differences. Races
which have long been domesticated, and have much varied, are precisely
those which were capable of bearing great changes, whose constitutions
were adapted to a diversity of climates. Nature changes slowly and by
degrees. According to many authors probably breeds of dogs are another
case of modified species freely crossing. There is no variety which
«illegible» has been «illegible» adapted to
peculiar soil or situation for a thousand years and another rigorously
adapted to another, till such can be produced, the question is not
tried{80}.
Man in past ages, could transport into different climates, animals and
plants which would freely propagate in such new climates. Nature could
effect, with selection, such changes slowly, so that precisely those
animals which are adapted to submit to great changes have given rise to
diverse races,—and indeed great doubt on this head{81}.
Before leaving this subject well to observe that it was shown that a
certain amount of variation is consequent on mere act of reproduction,
both by buds and sexually,—is vastly increased when parents
exposed for some generations to new conditions{82},
and we now find that many animals when exposed for first time to very
new conditions, are «as» incapable of breeding as hybrids.
It [probably] bears also on supposed fact of crossed animals when not
infertile, as in mongrels, tending to vary much, as likewise seems to be
the case, when true hybrids possess just sufficient fertility to
propagate with the parent breeds and inter se for some generations.
This is Koelreuter’s belief. These facts throw light on each other
and support the truth of each other, we see throughout a connection
between the reproductive faculties and exposure to changed conditions of
life whether by crossing or exposure of the individuals{83}.
Difficulties on theory of selection{84}.
It may be objected such perfect organs as eye and ear, could never be
formed, in latter less difficulty as gradations more perfect; at first
appears monstrous and to «the» end appears difficulty. But
think of gradation, even now manifest, (Tibia and Fibula). Everyone will
allow if every fossil preserved, gradation
infinitely more perfect; for possibility of selection a perfect
«?» gradation is required. Different groups of structure,
slight gradation in each group,—every analogy renders it probable
that intermediate forms have existed. Be it remembered what strange
metamorphoses; part of eye, not directly connected with vision, might
come to be [thus used] gradually worked in for this end,—swimming
bladder by gradation of structure is admitted to belong to the ear
system,—rattlesnake. [Woodpecker best adapted to climb.] In some
cases gradation not possible,—as vertebræ,—actually
vary in domestic animals,—less difficult if growth followed.
Looking to whole animals, a bat formed not for flight{85}.
Suppose we had flying fish{86}
and not one of our now called flying fish preserved, who would have
guessed intermediate habits. Woodpeckers and tree-frogs both live in
countries where no trees{87}.
The gradations by which each individual organ has arrived at its present state, and each individual animal with its aggregate of organs has arrived, probably never could be known, and all present great difficulties. I merely wish to show that the proposition is not so monstrous as it at first appears, and that if good reason can be advanced for believing the species have descended from common parents, the difficulty of imagining intermediate forms of structure not sufficient to make one at once reject the theory.
The mental powers of different animals in wild and tame state [present
still greater difficulties] require a separate section. Be it remembered
I have nothing to do with origin of memory, attention, and the different
faculties of the mind{88},
but merely with their differences in each of the great divisions of
nature. Disposition, courage, pertinacity «?», suspicion,
restlessness, ill-temper, sagacity and «the» reverse
unquestionably vary in animals and are inherited (Cuba wildness dogs,
rabbits, fear against particular object as man Galapagos{89}).
Habits purely corporeal, breeding season &c., time of going to rest
&c., vary and are hereditary, like the analogous habits of plants
which vary and are inherited. Habits of body, as manner of movement do.
and do. Habits, as pointing and setting on certain occasions do. Taste
for 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.
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, do. 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.
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.
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.
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.
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.
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.
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.
Give sketch of the Past,—beginning with facts appearing hostile under present knowledge,—then proceed to geograph. distribution,—order of appearance,—affinities,—morphology &c., &c.
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.]
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}.
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.
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.
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.
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}.
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.
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.
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}.
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}.]
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.
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.
The detection of transitional forms would be rendered more difficult on rising point of land.
The distribution therefore in the above enumerated points, even the trivial ones, which on any other «theory?» can be viewed as so many ultimate facts, all follow «in» a simple manner on the theory of the occurrence of species by «illegible» and being adapted by selection to «illegible», conjoined with their power of dispersal, and the steady geographico-geological changes which are now in progress and which undoubtedly have taken place. Ought to state the opinion of the immutability of species and the creation by so many separate acts of will of the Creator{134}.
Looking now to the affinities of organisms, without relation to their
distribution, and taking all fossil and recent, we see the degrees of
relationship are of different degrees and
arbitrary,—sub-genera,—genera,—sub-families, families,
orders and classes and kingdoms. The kind of classification which
everyone feels is most correct is called the natural system, but no can
define this. If we say with Whewell «that we have an»
undefined instinct of the importance of organs{135},
we have no means in lower
animals of saying which is most important, and yet everyone feels that
some one system alone deserves to be called natural. The true
relationship of organisms is brought before one by considering relations
of analogy, an otter-like animal amongst mammalia and an otter amongst
marsupials. In such cases external resemblance and habit of life and
the final end of whole organization very strong, yet no relation{136}.
Naturalists cannot avoid these terms of relation and affinity though
they use them metaphorically. If used in simple earnestness the natural
system ought to be a genealogical «one»; and our knowledge
of the points which are most easily affected in transmission are those
which we least value in considering the natural system, and practically
when we find they do vary we regard them of less value{137}.
In classifying varieties the same language is used and the same kind of
division: here also (in pine-apple){138}
we talk of the natural classification, overlooking similarity of the
fruits, because whole plant differs. The origin of sub-genera, genera,
&c., &c., is not difficult on notion of genealogical succession,
and accords with what we know of similar gradations of affinity in
domesticated organisms. In the same region the organic beings are
«illegible» related to each other and the external
conditions in many physical respects are allied{139}
and their differences of same kind, and therefore when a new species has
been selected and has obtained a place in the economy of nature, we
may suppose that generally it will tend to extend its range during
geographical changes, and thus, becoming isolated and exposed to new
conditions, will slightly alter and its structure by selection become
slightly remodified, thus we should get species of a sub-genus and
genus,—as varieties of merino-sheep,—varieties of British
and Indian cattle. Fresh species might go on forming and others become
extinct and all might become extinct, and then we should have
«an» extinct genus; a case formerly mentioned, of which
numerous cases occur in Palæontology. But more often the same
advantages which caused the new species to spread and become modified
into several species would favour some of the species being preserved:
and if two of the species, considerably different, each gave rise to
group of new species, you would have two genera; the same thing will go
on. We may look at case in other way, looking to future. According to
mere chance every existing species may generate another, but if any
species, A, in changing gets an advantage and that advantage (whatever
it may be, intellect, &c., &c., or some particular structure or
constitution) is inherited{140},
A will be the progenitor of several genera or even families in the hard
struggle of nature. A will go on beating out other forms, it might come
that A would people earth,—we may now not have one descendant on
our globe of the one or several original creations{141}.
External conditions air, earth, water being same{142}
on globe, and the communication not being perfect, organisms of widely
different descent might become adapted to
the same end and then we should have cases of analogy{143},
[they might even tend to become numerically representative]. From this
often happening each of the great divisions of nature would have their
representative eminently adapted to earth, to «air»{144},
to water, and to these in «illegible» and then these great
divisions would show numerical relations in their classification.
Nothing more wonderful in Nat. Hist. than looking at the vast number of organisms, recent and fossil, exposed to the most diverse conditions, living in the most distant climes, and at immensely remote periods, fitted to wholely different ends, yet to find large groups united by a similar type of structure. When we for instance see bat, horse, porpoise-fin, hand, all built on same structure{145}, having bones{146} with same name, we see there is some deep bond of union between them{147}, to illustrate this is the foundation and objects «?» «of» what is called the Natural System; and which is foundation of distinction «?» of true and adaptive characters{148}. Now this wonderful fact of hand, hoof, wing, paddle and claw being the same, is at once explicable on the principle of some parent-forms, which might either be «illegible» or walking animals, becoming through infinite number of small selections adapted to various conditions. We know that proportion, size, shape of bones and their accompanying soft parts vary, and hence constant selection would alter, to almost any purpose «?» the framework of an organism, but yet would leave a general, even closest similarity in it.
[We know the number of similar parts, as vertebræ and ribs can
vary, hence this also we might expect.] Also «if» the
changes carried on to a certain point, doubtless type will be lost, and
this is case with Plesiosaurus{149}.
The unity of type in past and present ages of certain great divisions
thus undoubtedly receives the simplest explanation.
There is another class of allied and almost identical facts, admitted by
the soberest physiologists, [from the study of a certain set of organs
in a group of organisms] and refers «? referring»
to a unity of type of different organs in the same individual,
denominated the science of “Morphology.” The «?
this» discovered by beautiful and regular series, and in the case
of plants from monstrous changes, that certain organs in an individual
are other organs metamorphosed. Thus every botanist considers petals,
nectaries, stamens, pistils, germen as metamorphosed leaf. They thus
explain, in the most lucid manner, the position and number of all parts
of the flower, and the curious conversion under cultivation of one part
into another. The complicated double set of jaws and palpi of
crustaceans{150},
and all insects are considered as metamorphosed «limbs» and
to see the series is to admit this phraseology. The skulls of the
vertebrates are undoubtedly composed of three metamorphosed
vertebræ; thus we can understand the strange form of
the separate bones which compose the casket holding man’s brain.
These{151}
facts differ but slightly from those of last section, if with wing,
paddle, hand and hoof, some common structure was yet visible, or could
be made out by a series of occasional monstrous conversions, and if
traces could be discovered of «the» whole having once
existed as walking or swimming instruments, these organs would be said
to be metamorphosed, as it is they are only said to exhibit a common
type.
This distinction is not drawn by physiologists, and is only implied by some by their general manner of writing. These facts, though affecting every organic being on the face of the globe, which has existed, or does exist, can only be viewed by the Creationist as ultimate and inexplicable facts. But this unity of type through the individuals of a group, and this metamorphosis of the same organ into other organs, adapted to diverse use, necessarily follows on the theory of descent{152}. For let us take case of Vertebrata, which if{153} they descended from one parent and by this theory all the Vertebrata have been altered by slow degrees, such as we see in domestic animals. We know that proportions alter, and even that occasionally numbers of vertebræ alter, that parts become soldered, that parts are lost, as tail and toes, but we know «that?» here we can see that possibly a walking organ might «?» be converted into swimming or into a gliding organ and so on to a flying organ. But such gradual changes would not alter the unity of type in their descendants, as parts lost and soldered and vertebræ. But we can see that if this carried to extreme, unity lost,—Plesiosaurus. Here we have seen the same organ is formed «?» «for» different purposes «ten words illegible»: and if, in several orders of vertebrata, we could trace origin «of» spinous processes and monstrosities &c. we should say, instead of there existing a unity of type, morphology{154}, as we do when we trace the head as being the vertebræ metamorphosed. Be it observed that Naturalists, as they use terms of affinity without attaching real meaning, here also they are obliged to use metamorphosis, without meaning that any parent of crustacean was really an animal with as many legs as crustacean has jaws. The theory of descent at once explains these wonderful facts.
Now few of the physiologists who use this language really suppose that
the parent of insect with the metamorphosed jaw, was an insect with
[more] so many legs, or that the parent of flowering plants, originally
had no stamens, or pistils or petals, but some other means of
propagation,—and so in other cases. Now according to our theory
during the infinite number of changes, we might expect that an organ
used for a purpose might be used for a different one by his descendant,
as must have been the case by our theory with the bat, porpoise, horse,
&c., which are descended from one parent. And if it so chanced that
traces of the former use and structure of the part should be retained,
which is manifestly possible if not probable, then we should have the
organs, on which morphology is founded and which instead of being
metaphorical becomes plain and «and instead of being»
utterly unintelligible becomes simple matter of fact{155}.
«Embryology.» This general unity of type in great groups of organisms (including of course these morphological cases) displays itself in a most striking manner in the stages through which the fœtus passes{156}. In early stage, the wing of bat, hoof, hand, paddle are not to be distinguished. At a still earlier «stage» there is no difference between fish, bird, &c. &c. and mammal. It is not that they cannot be distinguished, but the arteries{157} «illegible». It is not true that one passes through the form of a lower group, though no doubt fish more nearly related to fœtal state{158}.
This similarity at the earliest stage is remarkably shown in the course of the arteries which become greatly altered, as fœtus advances in life and assumes the widely different course and number which characterize full-grown fish and mammals. How wonderful that in egg, in water or air, or in womb of mother, artery{159} should run in same course.
Light can be thrown on this by our theory. The structure of each organism is chiefly adapted to the sustension of its life, when full-grown, when it has to feed itself and propagate{160}. The structure of a kitten is quite in secondary degree adapted to its habits, whilst fed by its mother’s milk and prey. Hence variation in the structure of the full-grown species will chiefly determine the preservation of a species now become ill-suited to its habitat, or rather with a better place opened to it in the economy of Nature. It would not matter to the full-grown cat whether in its young state it was more or less eminently feline, so that it become so when full-grown. No doubt most variation, (not depending on habits of life of individual) depends on early change{161} and we must suspect that at whatever time of life the alteration of fœtus is effected, it tends to appear at same period. When we «see» a tendency to particular disease in old age transmitted by the male, we know some effect is produced during conception, on the simple cell of ovule, which will not produce its effect till half a century afterwards and that effect is not visible{162}. So we see in grey-hound, bull-dog, in race-horse and cart-horse, which have been selected for their form in full-life, there is much less «?» difference in the few first days after birth{163}, than when full-grown: so in cattle, we see it clearly in cases of cattle, which differ obviously in shape and length of horns. If man were during 10,000 years to be able to select, far more diverse animals from horse or cow, I should expect there would be far less differences in the very young and fœtal state: and this, I think, throws light on above marvellous fact. In larvæ, which have long life selection, perhaps, does much,—in the pupa not so much{164} There is no object gained in varying form &c. of fœtus (beyond certain adaptations to mother’s womb) and therefore selection will not further act on it, than in giving to its changing tissues a tendency to certain parts afterwards to assume certain forms.
Thus there is no power to change the course of the arteries, as long as they nourish the fœtus; it is the selection of slight changes which supervene at any time during «illegible» of life.
The less differences of fœtus,—this has obvious meaning on this
view: otherwise how strange that a [monkey] horse, a man, a bat should
at one time of life have arteries, running in a manner, which is only
intelligibly useful in a fish! The natural system being on theory
genealogical, we can at once see, why fœtus, retaining traces of the
ancestral form, is of the highest value in classification.
There is another grand class of facts relating to what are called abortive organs. These consist of organs which the same reasoning power that shows us how beautifully these organs in some cases are adapted to certain end, declares in other cases are absolutely useless. Thus teeth in Rhinoceros{165}, whale, narwhal,—bone on tibia, muscles which do not move,—little bone of wing of Apteryx,—bone representing extremities in some snake,—little wings within «?» soldered cover of beetles,—men and bulls, mammæ: filaments without anthers in plants, mere scales representing petals in others, in feather-hyacinth whole flower. Almost infinitely numerous. No one can reflect on these without astonishment, can anything be clearer than that wings are to fly and teeth «to bite», and yet we find these organs perfect in every detail in situations where they cannot possibly be of their normal use{166}.
The term abortive organ has been thus applied
to above structure (as invariable as all other parts{167})
from their absolute similarity to monstrous cases, where from
accident, certain organs are not developed; as infant without arms or
fingers with mere stump representing them: teeth represented by mere
points of ossification: headless children with mere
button,—viscera represented by small amorphous masses,
&c.,—the tail by mere stump,—a solid horn by minute
hanging one{168}.
There is a tendency in all these cases, when life is preserved, for such
structures to become hereditary. We see it in tailless dogs and cats. In
plants we see this strikingly,—in Thyme, in Linum
flavum,—stamen in Geranium pyrenaicum{169}.
Nectaries abort into petals in Columbine «Aquilegia»,
produced from some accident and then become hereditary, in some cases
only when propagated by buds, in other cases by seed. These cases have
been produced suddenly by accident in early growth, but it is part of
law of growth that when any organ is not used it tends to diminish
(duck’s wing{170}?)
muscles of dog’s ears, «and of» rabbits, muscles
wither, arteries grow up. When eye born defective, optic nerve (Tuco
Tuco) is atrophied. As every part whether useful or not (diseases,
double flowers) tends to be transmitted to offspring, the origin of
abortive organs whether produced at the birth or slowly acquired is
easily understood in domestic races of organisms: [a struggle between
the atrophy and hereditariness. Abortive organs in domestic races.]
There will always be a struggle between atrophy of an organ rendered
useless, and
hereditariness{171}.
Because we can understand the origin of abortive organs in certain
cases, it would be wrong to conclude absolutely that all must have had
same origin, but the strongest analogy is in favour of it. And we can by
our theory, for during infinite changes some organ, we might have
anticipated, would have become useless. «We can» readily
explain the fact, so astounding on any other view, namely that organs
possibly useless have been formed often with the same exquisite care as
when of vital importance.
Our theory, I may remark would permit an organ «to» become
abortive with respect to its primary use, to be turned to any other
purpose, (as the buds in a cauliflower) thus we can see no difficulty in
bones of male marsupials being used as fulcrum of muscles, or style of
marygold{172},—indeed
in one point of view, the heads of [vertebrated] animal may be said to
be abortive vertebræ turned into other use: legs of some crustacea
abortive jaws, &c., &c. De Candolle's analogy of table covered
with dishes{173}.
«The following passage was possibly intended to be inserted
here.» Degradation and complication see Lamarck: no tendency to
perfection: if room, [even] high organism would have greater power in
beating lower one, thought «?» to be selected for a degraded
end.