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all our existing species.

In 1826 Professor Grant, in the concluding paragraph in his well-known
paper ("Edinburgh Philosophical Journal," vol. xiv. p. 283) on the Spon-
gilla, clearly declares his belief that species are descended from other
species, and that they become improved in the course of modification. This
same view was given in his Fifty-fifth Lecture, published in the "Lancet"
in 1834.

In 1 83 1 Mr. Patrick Matthew published his work on "Naval Timber and
Arboriculture," in which he gives precisely the same view on the origin of
species as that (presently to be alluded to) propounded by Mr. Wallace
and myself in the "Linnean Journal," and as that enlarged in the present
volume. Unfortunately the view was given by Mr. Matthew very briefly in
scattered passages, in an appendix to a work on a diff"erent subject, so that
it remained unnoticed until Mr, Matthew himself drew attention to it in
the "Gardeners' Chronicle," on April 7, i860. The differences of Mr.
Matthew's views from mine are not of much importance: he seems to con-
sider that the world was nearly depopulated at successive periods, and then
restocked; and he gives as an alternative, that new forms may be generated
"without the presence of any mould or germ of former aggregates." I am
not sure that I understand some passages; but it seems that he attributes
much influence to the direct action of the conditions of life. He clearly saw,
however, the full force of the principle of natural selection.

The celebrated geologist and naturalist, Von Buch, in his excellent "De-
scription Physique des Isles Canaries" (1836, p. 147), clearly expresses his
belief that varieties slowly become changed into permanent species, which
are no longer capable of intercrossing.

Rafinesque, in his "New Flora of North America," published in 1836,
wrote (p. 6) as follows: "All species might have been vaiieties once, and


many varieties are gradually becoming species by assuming constant and
peculiar characters"; but further on (p. i8), he adds, "except the original
types or ancestors of the genus."

In 1843-44 Professor Haldeman ("Boston Journal of Nat. Hist. U.
States," vol. iv. p. 468) has ably given the arguments for and against the
hypothesis of the development and modification of species: he seems to
lean toward the side of change.

The "Vestiges of Creation" appeared in 1844. In the tenth and much
improved edition (1853) the anonymous author says (p. 155) : "The
proposition determined on after much consideration is, that the several
series of animated beings, from the simplest and oldest up to the highest
and most recent, are, under the providence of God, the results, first, of an
impulse which has been imparted to the forms of life, advancing them in
definite times, by generation, through grades of organization terminating
in the highest dicotyledons and vertebrata, these grades being few in num-
ber, and generally marked by intervals of organic character, which we find
to be a practical difficulty in ascertaining affinities; second, of another im-
pulse connected with the vital forces, tending, in the course of generations,
to modify organic structures in accordance with external circumstances, as
food, the nature of the habitat, and the meteoric agencies, these being the
'adaptations' of the natural theologian." The author apparently believes
that organization progresses by sudden leaps, but that the effects produced
by the conditions of life are gradual. He argues with much force on general
grounds that species are not immutable productions. But I cannot see how
the two supposed "impulses" account in a scientific sense for the numerous
and beautiful coadaptations which we see throughout nature; I cannot see
that we thus gain any insight how, for instance, a woodpecker has become
adapted to its peculiar habits of life. The work, from its powerful and
brilliant style, though displaying in the early editions little accurate knowl-
edge and a great want of scientific caution, immediately had a very wide
circulation. In my opinion it has done excellent service in this country in
calling attention to the subject, in removing prejudice, and in thus prepar-
ing the ground for the reception of analogous views.

In 1846 the veteran geologist M. J. d'Omalius d'Halloy published in an
excellent though short paper ("Bulletins de I'Acad. Roy. Bruxelles," torn,
xiii. p. 581) his opinion that it is more probable that new species have been
produced by descent with modification than that they have been separately
created: the author first promulgated this opinion in 1831.

Professor Owen, in 1849 ("Nature of Limbs," p. 86), wrote as follows:
"The archetypal idea was manifested in the flesh under divers such modi-
fications, upon this planet, long prior to the existence of those animal
species that actually exemplify it. To what natural laws or secondary
causes the orderly succession and progression of such organic phenomena
may have been committed, we, as yet, are ignorant." In his address to the
British Association, in 1858, he speaks (p. li) of "the axiom of the continu-
ous operation of creative power, or of the ordained becoming of living


things." Further on (p. xc), after referring to geographical distribution, he
adds, "These phenomena shake our confidence in the conclusion that the
Apteryx of New Zealand and the Red Grouse of England were distinct
creations in and for those islands respectively. Always, also, it may be well
to bear in mind that by the word 'creation' the zoologist means 'a process he
knows not what.' " He amplifies this idea by adding that when such cases
as that of the Red Grouse are "enumerated by the zoologist as evidence of
distinct creation of the bird in and for such islands, he chiefly expresses
that he knows not how the Red Grouse came to be there, and there exclu-
sively; signifying also, by this mode of expressing such ignorance, his belief
that both the bird and the islands owed their origin to a great first Creative
Cause." If we interpret these sentences given in the same address, one by
the other, it appears that this eminent philosopher felt in 1858 his con-
fidence shaken that the Apteryx and the Red Grouse first appeared in their
respective homes "he knew not how," or by some process "he knew not

This address was delivered after the papers by Mr. Wallace and myself
on the Origin of Species, presently to be referred to, had been read before
the Linnean Society. When the first edition of this work was published, I
was so completely deceived, as were many others, by such expressions as
"the continuous operation of creative power," that I included Professor
Owen with other palaeontologists as being firmly convinced of the im-
mutability of species; but it appears ("Anat. of Vertebrates," vol. iii. p. 796)
that this was on my part a preposterous error. In the last edition of this
work I inferred, and the inference still seems to me perfectly just, from a
passage beginning with the words "no doubt the type-form," etc. (Ibid.,
vol. i. p. xxxv), that Professor Owen admitted that natural selection may
have done something in the formation of a new species; but this it appears
(Ibid., vol. iii. p. 798) is inaccurate and without evidence. I also gave
some extracts from a correspondence between Professor Owen and the
editor of the "London Review," from which it appeared manifest to the
editor as well as to myself, that Professor Owen claimed to have promul-
gated the theory of natural selection before I had done so; and I expressed
my surprise and satisfaction at this announcement; but as far as it is possible
to understand certain recently published passages (Ibid., vol. iii. p. 798) I
have either partially or wholly again fallen into error. It is consolatory to
me that others find Professor Owen's controversial writings as difficult to
understand and to reconcile with each other, as I do. As far as the mere
enunciation of the principle of natural selection is concerned, it is quite im-
material whether or not Professor Owen preceded me, for both of us, as
shown in this historical sketch, were long ago preceded by Dr. Wells and
Mr. Matthew.

M. Isidore Geoff roy Saint-Hilaire, in his lectures delivered in 1850 (of
which a resume appeared in the "Revue et Mag. de Zoolog.," Jan., 1851),
briefly gives his reason for believing that specific characters "sont fixes, pour
chaque espece, tant qu'elle se perpetue au milieu des memes circonstances :


ils se modifient, si les circonstances ambiantes viennent a changer." "En
resume, Vobservation des animaux sauvages demontre deja la variabilite
limitee des especes. Les experiences sur les animaux sauvages devenus
domestiques, et sur les animaux domestiques redevenus sauvages, la de-
montrent plus clairement encore. Ces memes experiences prouvent, de plus,
que les differences produites peuvent etre de valeur generique." In his
"Hist. Nat. Generale" (torn. ii. p. 430, 1859) he amplifies analogous con-

From a circular lately issued it appears that Dr. Freke, in 1851 ("Dublin
Medical Press," p. 322), propounded the doctrine that all organic beings
have descended from one primordial form. His grounds of belief and treat-
ment of the subject are wholly different from mine; but as Dr. Freke has
now (1861) published his Essay on the "Origin of Species by means of
Organic Affinity," the difficult attempt to give any idea of his views would
be superfluous on my part.

Mr. Herbert Spencer, in an essay (originally published in the "Leader,"
March, 1852, and repubUshed in his "Essays," in 1858), has contrasted the
theories of the Creation and the Development of organic beings with re-
markable skill and force. He argues from the analogy of domestic produc-
tions, from the changes which the embryos of many species undergo, from
the difficulty of distinguishing species and varieties, and from the principle
of general gradation, that species have been modified; and he attributes
the modification to the change of circumstances. The author (1855) has
also treated Psychology on the principle of the necessary acquirement of
each mental power and capacity by gradation.

In 1852 M. Naudin, a distinguished botanist, expressly stated, in an ad-
mirable paper on the Origin of Species ("Revue Horticole," p. 102; since
partly republished in the "Nouvelles Archives du Museum," tom. i. p. 171),
his belief that species are formed in an analogous manner as varieties are
under cultivation; and the latter process he attributes to man's power of
selection. But he does not show how selection acts under nature. He be-
lieves, like Dean Herbert, that species, when nascent, were more plastic
than at present. He lays weight on what he calls the principle of finality,
"puissance mysterieuse, indeterminee; fatalite pour les uns; pour les autres
volonte providentielle, dont Taction incessante sur les etres vivantes deter-
mine, a toutes les epoques de 1' existence du monde, la forme, le volume, et
la duree de chacun d'eux, en raison de sa destinee dans I'ordre de choses
dont il fait partie. G'est cette puissance qui harmonise chaque membre a
I'ensemble, en I'appropriant a la fonction qu'il doit remplir dans I'organisme
generale de la nature, fonction qui est pour lui sa raison d'etre."*

*From references in Bronn's "Untersuchungen iiber die Entwickelungs-Gesetze,"
it appears that the celebrated botanist and palaeontologist Unger published, in 1852,
his belief that species undergo development and modification. Dalton, likewise, in
Pander and Dalton's work on Fossil Sloths, expressed, in 182 1, a similar belief. Similar
views have, as is well known, been maintained by Oken in his mystical "Natur-
Philosophie." From other references in Godron's work "Sur I'Espece," it seems that


In 1853 a celebrated geologist, Count Keyserling ("Bulletin de la Soc.
Geolog.," 2d ser., torn. x. p. 357) suggested that as new diseases, supposed to
have been caused by some miasma, have arisen and spread over the world,
so at certain periods the germs of existing species may have been chemically
affected by circumambient molecules of a particular nature, and thus have
given rise to new forms.

In this same year, 1853, Dr. Schaaffhausen published an excellent
pamphlet ("Verhand. des Naturhist. Vereins der Preuss. Rheinlands," etc.),
in which he maintains the development of organic forms on the earth. He
infers that many species have kept true for long periods, whereas a few
have become modified. The distinction of species he explains by the destruc-
tion of intermediate graduated forms. "Thus living plants and animals are
not separated from the extinct by new creations, but are to be regarded as
their descendants through continued reproduction."

A well-known French botanist, M. Lecoq, writes in 1854 ("Etudes sur
Geograph. Bot.," tom. i. p. 250) : "On voit que nos recherches sur la fixite
ou la variation de I'espece, nous conduisent directement aux idees emises
par deux hommes justement celebres, Geoffroy Saint-Hilaire et Goethe."
Some other passages scattered through M. Lecoq' s large work make it a
little doubtful how far he extends his views on the modification of species.

The "Philosophy of Creation" has been treated in a masterly manner by
the Rev. Baden Powell, in his "Essays on the Unity of Worlds," 1855.
Nothing can be more striking than the manner in which he shows that the
introduction of new species is "a regular, not a casual phenomenon," or, as
Sir John Herschel expresses it, "a natural in contradistinction to a miracu-
lous process."

The third volume of the "Journal of the Linnean Society" contains
papers, read July i, 1858, by Mr. Wallace and myself, in which, as stated in
the introductory remarks to this volume, the theory of Natural Selection is
promulgated by Mr. Wallace with admirable force and clearness.

Von Baer, toward whom all zoologists feel so profound a respect, ex-
pressed about the year 1859 (see Prof. Rudolph Wagner, "Zoologisch-
Anthropologische Untersuchungen," 1861, s. 51) his conviction, chiefly
grounded on the laws of geographical distribution, that forms now perfectly
distinct have descended from a single parent-form.

In June, 1859, Professor Huxley gave a lecture before the Royal Institu-
tion on the "Persistent Types of Animal Life." Referring to such cases, he
remarks, "It is difficult to comprehend the meaning of such facts as these,
if we suppose that each species of animal and plant, or each great type of
organization, was formed and placed upon the surface of the globe at long
intervals by a distinct act of creative power; and it is well to recollect that

Bory St. Vincent, Burdach, Poiret, and Fries have all admitted that new species are
continually being produced. I may add, that of the thirty-four authors named in this
Historical Sketch who believe in the modification of species, or at least disbelieve in
separate acts of creation, twenty-seven have written on special branches of natural
history or geology.


such an assumption is as unsupported by tradition or revelation as it is
opposed to the general analogy of nature. If, on the other hand, we view
Tersistent Types' in relation to that hypothesis which supposes the species
living at any time to be the result of the gradual modification of pre-exist-
ing species, a hypothesis which, though unproven, and sadly damaged by
some of its supporters, is yet the only one to which physiology lends any
countenance; their existence would seem to show that the amount of modi-
fication which living beings have undergone during geological time is but
very small in relation to the whole series of changes which they have

In December, 1859, Dr. Hooker published his "Introduction to the Aus-
tralian Flora." In the first part of this great work he admits the truth of
the descent and modification of species, and supports this doctrine by many
original observations.

The first edition of this work was published on November 24, 1859, and
the second edition on January 7, i860.




Aberrant. — Forms or groups of animals or plants which deviate in important char-
acters from their nearest allies, so as not to be easily included in the same group
with them, are said to be aberrant.

Aberration (in Optics) . — In the refraction of light by a convex lens the rays passing
through different parts of the lens are brought to a focus at slightly different
distances — this is called spherical aberration; at the same time the colored rays
are separated by the prismatic action of the lens and likewise brought to a focus
at different distances — this is chromatic aberration.

Abnormal. — Contrary to the general rule.

Aborted. — ^An organ is said to be aborted, when its development has been arrested
at a very early stage.

Albinism. — ^Albinos are animals in which the usual coloring matters characteristic
of the species have not been produced in the skin and its appendages. Albinism
is the state of being an Albino.

ALGi^.^ — ^A class of plants including the ordinary sea-weeds and the filamentous fresh-
water weeds.

Alternation of Generations. — ^This term is applied to a peculiar mode of repro-
duction which prevails among many of the lower animals, in which the egg
produces a living form quite different from its parent, but from which the
parent-form is reproduced by a process of budding, or by the division of the
substance of the first product of the egg.

Ammonites. — ^A group of fossil, spiral, chambered shells, allied to the existing
pearly Nautilus, but having the partitions between the chambers waved in com-
plicated patterns at their junction with the outer wall of the shell.

Analogy. — ^The resemblance of structures which depends upon similarity of func-
tion, as in the wings of insects and birds. Such structures are said to be
analogous, and to be analogues of each other.

Animalcule. — ^A minute animal: generally applied to those visible only by the

Annelids. — A class of worms in which the surface of the body exhibits a more or
less distinct division into rings or segments, generally provided with appendages
for locomotion and with gills. It includes the ordinary marine worms, the earth-
worms and the leeches.

Antenna. — Jointed organs appended to the head in Insects, Crustacea and Centi-
pedes, and not belonging to the mouth.

Anthers. — The summits of the stamens of flowers, in which the pollen or fertilizing
dust is produced.

Aplagentalia, Aplacentata or Aplagental Mammals. See Mammalia.

^I am indebted to the kindness of Mr. W. S. Dallas for this Glossary, which has been
given because several readers have complained to me that some of the terms used were
unintelligible to them. Mr. Dallas has endeavored to give the explanations of the
terms in as popular a form as possible.



Archetypal. — Of or belonging to the Archetype, or ideal primitive form upon
which all the beings of a group seem to be organized.

Artigulata. — ^A great division of the Animal Kingdom characterized generally by
having the surface of the body divided into rings called segments, a greater or
less number of which are furnished with jointed legs (such as Insects, Crusta-
ceans and Centipedes).

Asymmetrical. — Having the two sides unlike.

Atrophied. — Arrested in development at a very early stage.

Balanus. — The genus including the common Acorn-shells which live in abundance

on the rocks of the seacoast.
Batrachl\ns. — ^A class of animals allied to the Reptiles, but undergoing a peculiar

metamorphosis, in which the young animal is generally aquatic and breathes by

gills. {Examples, Frogs, Toads, and Newts.)
Bowlders. — Large transported blocks of stone generally embedded in clays or

Brachiopoda. — A class of marine Mollusca, or soft-bodied animals, furnished with a

bivalve shell, attached to submarine objects by a stalk which passes through an

aperture in one of the valves, and furnished with fringed arms, by the action

of which food is carried to the mouth.
Branchi^. — Gills or organs for respiration in water.
Branchial. — Pertaining to gills or branchiae.

Cambrian System. — ^A series of very ancient Palaeozoic rocks, between the Lau-
rentian and the Silurian. Until recently these were regarded as the oldest
fossiliferous rocks.

Canid/e. — The Dog-family, including the Dog, Wolf, Fox, Jackal, etc.

Carapace. — The shell enveloping the anterior part of the body in Crustaceans
generally; applied also to the hard shelly pieces of the Cirripedes.

Carboniferous. — This term is applied to the great formation which includes,
among other rocks, the coal-measures. It belongs to the oldest, or Palaeozoic,
system of formations.

Caudal. — Of or belonging to the tail.

Cephalopods. — The highest class of the Mollusca, or soft-bodied animals, char-
acterized by having the mouth surrounded by a greater or less number of fleshy
arms or tentacles, which, in most living species are furnished with sucking-cups.
{Examples, Cuttle-fish, Nautilus.)

Cetacea. — An order of Mammalia, including the Whales, Dolphins, etc., having the
form of the body fish-like, the skin naked, and only the fore limbs developed.

Chelonia. — ^An order of Reptiles including the Turtles, Tortoises, etc.

Cirripedes. — An order of Crustaceans including the Barnacles and Acorn-shells.
Their young resemble those of many other Crustaceans in form; but when
mature they are always attached to other objects, either directly or by means of
a stalk, and their bodies are enclosed by a calcareous shell composed of several
pieces, two of which can open to give issue to a bunch of curled, jointed
tentacles, which represent the limbs.

Coccus. — The genus of Insects including the Cochineal. In these the male is a
minute, winged fly, and the female generally a motionless, berry-like mass.

Cocoon. — A case usually of silky material, in which insects are frequently enveloped
during the second or resting-stage (pupa) of their existence. The term "cocoon-
stage" is here used as equivalent to "pupa-stage."


CCELOSPERMOUS. — ^A term applied to those fruits of the Umbelliferae which have

the seed hollowed on the inner face.
CoLEOPTERA. — Bectlcs, an order of Insects having a biting mouth and the first pair

of wings more or less horny, forming sheaths for the second pair, and usually

meeting in a straight line down the middle of the back.
Column. — A peculiar organ in the flowers of Orchids, in which the stamens, style

and stigma (or the reproductive parts) are united,
CoMPOsiT/E or CoMPOsiTOus Plants. — Plants in which the inflorescence consists

of numerous small flowers (florets) brought together into a dense head, the base

of which is enclosed by a common envelope. {Examples, the Daisy, Dandelions,

Conferva. — The filamentous weeds of fresh water.
Conglomerate. — ^A rock made up of fragments of rock or pebbles, cemented

together by some other material.
Corolla. — The second envelope of a flower usually composed of colored, leaf-like

organs (petals), which may be united by their edges either in the basal part or

Correlation. — The normal coincidence of one phenomenon, character, etc., with

Corymb. — A bunch of flowers in which those springing from the lower part of the

flower-stalks are supported on long stalks so as to be nearly on a level with the

upper ones.
Cotyledons. — The first or seed-leaves of plants.
Crustaceans. — A class of articulated animals, having the skin of the body generally

more or less hardened by the deposition of calcareous matter, breathing by

means of gills. {Examples, Crab, Lobster, Shrimp, etc.)
CuRCULio. — The old generic term for the Beetles known as Weevils, characterized

by their four jointed feet, and by the head being produced into a sort of beak,

upon the sides of which the antennae are inserted.
Cutaneous. — Of or belonging to the skin.

Degradation. — The wearing down of land by the action of the sea or of meteoric

Denudation. — The wearing away of the surface of the land by water.

Devonian System or Formation. — A series of Palaeozoic rocks, including the Old
Red Sandstone.

Dicotyledons or Dicotyledonous Plants. — ^A class of plants characterized by
having two seed-leaves, by the formation of new wood between the bark and
the old wood (exogenous growth) and by the reticulation of the veins of the

Online LibraryCharles DarwinThe origin of species → online text (page 49 of 50)