Henry Adams - "Mont Saint Michel and Chartres"

John Lothrop Motley - "History of the United Netherlands, 1600"

Sam Vaknin - "Issues in Ethics"

E. P. Roe - "Miss Lou"

New Philadelphia Book Publisher Highlights Local Talent
Book and Publishing News from Publishers Newswire(tm)

Looking for Child to be on Cover of a New Book, 'The Model Child'
PHILADELPHIA, Pa. -- The Philadelphia literary world will celebrate the launch of two new players today, April 10th: Kay Square Press, a new publishing company focused on Philadelphia-area artists, their stories, and their art; and Kay Square's first release, 'With the Rich and Mighty: Emlen Etting of Philadelphia' (ISBN: 978-0-9815129-0-7), a critical biography by Kenneth C. Kaleta.

FlatSigned Press Alleges Don Imus Remarks Damage Legacy of President Gerald R. Ford
NEW YORK, N.Y. -- Nathan Yungerberg, an accomplished model scout and professional child photographer is launching a nation-wide casting call to find the cover model for his highly anticipated book release, 'The Model Child: A Parents Guide to the Child Modeling Industry' (ISBN: 978-0-9817018-0-6).

Books: On the Origin of Species

C >> Charles Darwin >> On the Origin of Species




This relation between the power and extent of migration of a species,
either at the present time or at some former period under different
physical conditions, and the existence at remote points of the world
of other species allied to it, is shown in another and more general
way. Mr. Gould remarked to me long ago, that in those genera of birds
which range over the world, many of the species have very wide ranges.
I can hardly doubt that this rule is generally true, though it would
be difficult to prove it. Amongst mammals, we see it strikingly
displayed in Bats, and in a lesser degree in the Felidae and Canidae.
We see it, if we compare the distribution of butterflies and beetles.
So it is with most fresh-water productions, in which so many genera
range over the world, and many individual species have enormous
ranges. It is not meant that in world-ranging genera all the species
have a wide range, or even that they have on an AVERAGE a wide range;
but only that some of the species range very widely; for the facility
with which widely-ranging species vary and give rise to new forms will
largely determine their average range. For instance, two varieties of
the same species inhabit America and Europe, and the species thus has
an immense range; but, if the variation had been a little greater, the
two varieties would have been ranked as distinct species, and the
common range would have been greatly reduced. Still less is it meant,
that a species which apparently has the capacity of crossing barriers
and ranging widely, as in the case of certain powerfully-winged birds,
will necessarily range widely; for we should never forget that to
range widely implies not only the power of crossing barriers, but the
more important power of being victorious in distant lands in the
struggle for life with foreign associates. But on the view of all the
species of a genus having descended from a single parent, though now
distributed to the most remote points of the world, we ought to find,
and I believe as a general rule we do find, that some at least of the
species range very widely; for it is necessary that the unmodified
parent should range widely, undergoing modification during its
diffusion, and should place itself under diverse conditions favourable
for the conversion of its offspring, firstly into new varieties and
ultimately into new species.

In considering the wide distribution of certain genera, we should bear
in mind that some are extremely ancient, and must have branched off
from a common parent at a remote epoch; so that in such cases there
will have been ample time for great climatal and geographical changes
and for accidents of transport; and consequently for the migration of
some of the species into all quarters of the world, where they may
have become slightly modified in relation to their new conditions.
There is, also, some reason to believe from geological evidence that
organisms low in the scale within each great class, generally change
at a slower rate than the higher forms; and consequently the lower
forms will have had a better chance of ranging widely and of still
retaining the same specific character. This fact, together with the
seeds and eggs of many low forms being very minute and better fitted
for distant transportation, probably accounts for a law which has long
been observed, and which has lately been admirably discussed by Alph.
de Candolle in regard to plants, namely, that the lower any group of
organisms is, the more widely it is apt to range.

The relations just discussed,--namely, low and slowly-changing
organisms ranging more widely than the high,--some of the species of
widely-ranging genera themselves ranging widely,--such facts, as
alpine, lacustrine, and marsh productions being related (with the
exceptions before specified) to those on the surrounding low lands and
dry lands, though these stations are so different--the very close
relation of the distinct species which inhabit the islets of the same
archipelago,--and especially the striking relation of the inhabitants
of each whole archipelago or island to those of the nearest
mainland,--are, I think, utterly inexplicable on the ordinary view of
the independent creation of each species, but are explicable on the
view of colonisation from the nearest and readiest source, together
with the subsequent modification and better adaptation of the
colonists to their new homes.

SUMMARY OF LAST AND PRESENT CHAPTERS.

In these chapters I have endeavoured to show, that if we make due
allowance for our ignorance of the full effects of all the changes of
climate and of the level of the land, which have certainly occurred
within the recent period, and of other similar changes which may have
occurred within the same period; if we remember how profoundly
ignorant we are with respect to the many and curious means of
occasional transport,--a subject which has hardly ever been properly
experimentised on; if we bear in mind how often a species may have
ranged continuously over a wide area, and then have become extinct in
the intermediate tracts, I think the difficulties in believing that
all the individuals of the same species, wherever located, have
descended from the same parents, are not insuperable. And we are led
to this conclusion, which has been arrived at by many naturalists
under the designation of single centres of creation, by some general
considerations, more especially from the importance of barriers and
from the analogical distribution of sub-genera, genera, and families.

With respect to the distinct species of the same genus, which on my
theory must have spread from one parent-source; if we make the same
allowances as before for our ignorance, and remember that some forms
of life change most slowly, enormous periods of time being thus
granted for their migration, I do not think that the difficulties are
insuperable; though they often are in this case, and in that of the
individuals of the same species, extremely grave.

As exemplifying the effects of climatal changes on distribution, I
have attempted to show how important has been the influence of the
modern Glacial period, which I am fully convinced simultaneously
affected the whole world, or at least great meridional belts. As
showing how diversified are the means of occasional transport, I have
discussed at some little length the means of dispersal of fresh-water
productions.

If the difficulties be not insuperable in admitting that in the long
course of time the individuals of the same species, and likewise of
allied species, have proceeded from some one source; then I think all
the grand leading facts of geographical distribution are explicable on
the theory of migration (generally of the more dominant forms of
life), together with subsequent modification and the multiplication of
new forms. We can thus understand the high importance of barriers,
whether of land or water, which separate our several zoological and
botanical provinces. We can thus understand the localisation of
sub-genera, genera, and families; and how it is that under different
latitudes, for instance in South America, the inhabitants of the
plains and mountains, of the forests, marshes, and deserts, are in so
mysterious a manner linked together by affinity, and are likewise
linked to the extinct beings which formerly inhabited the same
continent. Bearing in mind that the mutual relations of organism to
organism are of the highest importance, we can see why two areas
having nearly the same physical conditions should often be inhabited
by very different forms of life; for according to the length of time
which has elapsed since new inhabitants entered one region; according
to the nature of the communication which allowed certain forms and not
others to enter, either in greater or lesser numbers; according or
not, as those which entered happened to come in more or less direct
competition with each other and with the aborigines; and according as
the immigrants were capable of varying more or less rapidly, there
would ensue in different regions, independently of their physical
conditions, infinitely diversified conditions of life,--there would be
an almost endless amount of organic action and reaction,--and we
should find, as we do find, some groups of beings greatly, and some
only slightly modified,--some developed in great force, some existing
in scanty numbers--in the different great geographical provinces of
the world.

On these same principles, we can understand, as I have endeavoured to
show, why oceanic islands should have few inhabitants, but of these a
great number should be endemic or peculiar; and why, in relation to
the means of migration, one group of beings, even within the same
class, should have all its species endemic, and another group should
have all its species common to other quarters of the world. We can see
why whole groups of organisms, as batrachians and terrestrial mammals,
should be absent from oceanic islands, whilst the most isolated
islands possess their own peculiar species of aerial mammals or bats.
We can see why there should be some relation between the presence of
mammals, in a more or less modified condition, and the depth of the
sea between an island and the mainland. We can clearly see why all the
inhabitants of an archipelago, though specifically distinct on the
several islets, should be closely related to each other, and likewise
be related, but less closely, to those of the nearest continent or
other source whence immigrants were probably derived. We can see why
in two areas, however distant from each other, there should be a
correlation, in the presence of identical species, of varieties, of
doubtful species, and of distinct but representative species.

As the late Edward Forbes often insisted, there is a striking
parallelism in the laws of life throughout time and space: the laws
governing the succession of forms in past times being nearly the same
with those governing at the present time the differences in different
areas. We see this in many facts. The endurance of each species and
group of species is continuous in time; for the exceptions to the rule
are so few, that they may fairly be attributed to our not having as
yet discovered in an intermediate deposit the forms which are therein
absent, but which occur above and below: so in space, it certainly is
the general rule that the area inhabited by a single species, or by a
group of species, is continuous; and the exceptions, which are not
rare, may, as I have attempted to show, be accounted for by migration
at some former period under different conditions or by occasional
means of transport, and by the species having become extinct in the
intermediate tracts. Both in time and space, species and groups of
species have their points of maximum development. Groups of species,
belonging either to a certain period of time, or to a certain area,
are often characterised by trifling characters in common, as of
sculpture or colour. In looking to the long succession of ages, as in
now looking to distant provinces throughout the world, we find that
some organisms differ little, whilst others belonging to a different
class, or to a different order, or even only to a different family of
the same order, differ greatly. In both time and space the lower
members of each class generally change less than the higher; but there
are in both cases marked exceptions to the rule. On my theory these
several relations throughout time and space are intelligible; for
whether we look to the forms of life which have changed during
successive ages within the same quarter of the world, or to those
which have changed after having migrated into distant quarters, in
both cases the forms within each class have been connected by the same
bond of ordinary generation; and the more nearly any two forms are
related in blood, the nearer they will generally stand to each other
in time and space; in both cases the laws of variation have been the
same, and modifications have been accumulated by the same power of
natural selection.


CHAPTER 13. MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY:
EMBRYOLOGY: RUDIMENTARY ORGANS.

CLASSIFICATION, groups subordinate to groups.
Natural system.
Rules and difficulties in classification, explained on the theory of
descent with modification.
Classification of varieties.
Descent always used in classification.
Analogical or adaptive characters.
Affinities, general, complex and radiating.
Extinction separates and defines groups.
MORPHOLOGY, between members of the same class, between parts of the
same individual.
EMBRYOLOGY, laws of, explained by variations not supervening at an
early age, and being inherited at a corresponding age.
RUDIMENTARY ORGANS; their origin explained.
Summary.

From the first dawn of life, all organic beings are found to resemble
each other in descending degrees, so that they can be classed in
groups under groups. This classification is evidently not arbitrary
like the grouping of the stars in constellations. The existence of
groups would have been of simple signification, if one group had been
exclusively fitted to inhabit the land, and another the water; one to
feed on flesh, another on vegetable matter, and so on; but the case is
widely different in nature; for it is notorious how commonly members
of even the same subgroup have different habits. In our second and
fourth chapters, on Variation and on Natural Selection, I have
attempted to show that it is the widely ranging, the much diffused and
common, that is the dominant species belonging to the larger genera,
which vary most. The varieties, or incipient species, thus produced
ultimately become converted, as I believe, into new and distinct
species; and these, on the principle of inheritance, tend to produce
other new and dominant species. Consequently the groups which are now
large, and which generally include many dominant species, tend to go
on increasing indefinitely in size. I further attempted to show that
from the varying descendants of each species trying to occupy as many
and as different places as possible in the economy of nature, there is
a constant tendency in their characters to diverge. This conclusion
was supported by looking at the great diversity of the forms of life
which, in any small area, come into the closest competition, and by
looking to certain facts in naturalisation.

I attempted also to show that there is a constant tendency in the
forms which are increasing in number and diverging in character, to
supplant and exterminate the less divergent, the less improved, and
preceding forms. I request the reader to turn to the diagram
illustrating the action, as formerly explained, of these several
principles; and he will see that the inevitable result is that the
modified descendants proceeding from one progenitor become broken up
into groups subordinate to groups. In the diagram each letter on the
uppermost line may represent a genus including several species; and
all the genera on this line form together one class, for all have
descended from one ancient but unseen parent, and, consequently, have
inherited something in common. But the three genera on the left hand
have, on this same principle, much in common, and form a sub-family,
distinct from that including the next two genera on the right hand,
which diverged from a common parent at the fifth stage of descent.
These five genera have also much, though less, in common; and they
form a family distinct from that including the three genera still
further to the right hand, which diverged at a still earlier period.
And all these genera, descended from (A), form an order distinct from
the genera descended from (I). So that we here have many species
descended from a single progenitor grouped into genera; and the genera
are included in, or subordinate to, sub-families, families, and
orders, all united into one class. Thus, the grand fact in natural
history of the subordination of group under group, which, from its
familiarity, does not always sufficiently strike us, is in my judgment
fully explained.

Naturalists try to arrange the species, genera, and families in each
class, on what is called the Natural System. But what is meant by this
system? Some authors look at it merely as a scheme for arranging
together those living objects which are most alike, and for separating
those which are most unlike; or as an artificial means for
enunciating, as briefly as possible, general propositions,--that is,
by one sentence to give the characters common, for instance, to all
mammals, by another those common to all carnivora, by another those
common to the dog-genus, and then by adding a single sentence, a full
description is given of each kind of dog. The ingenuity and utility of
this system are indisputable. But many naturalists think that
something more is meant by the Natural System; they believe that it
reveals the plan of the Creator; but unless it be specified whether
order in time or space, or what else is meant by the plan of the
Creator, it seems to me that nothing is thus added to our knowledge.
Such expressions as that famous one of Linnaeus, and which we often
meet with in a more or less concealed form, that the characters do not
make the genus, but that the genus gives the characters, seem to imply
that something more is included in our classification, than mere
resemblance. I believe that something more is included; and that
propinquity of descent,--the only known cause of the similarity of
organic beings,--is the bond, hidden as it is by various degrees of
modification, which is partially revealed to us by our
classifications.

Let us now consider the rules followed in classification, and the
difficulties which are encountered on the view that classification
either gives some unknown plan of creation, or is simply a scheme for
enunciating general propositions and of placing together the forms
most like each other. It might have been thought (and was in ancient
times thought) that those parts of the structure which determined the
habits of life, and the general place of each being in the economy of
nature, would be of very high importance in classification. Nothing
can be more false. No one regards the external similarity of a mouse
to a shrew, of a dugong to a whale, of a whale to a fish, as of any
importance. These resemblances, though so intimately connected with
the whole life of the being, are ranked as merely "adaptive or
analogical characters;" but to the consideration of these resemblances
we shall have to recur. It may even be given as a general rule, that
the less any part of the organisation is concerned with special
habits, the more important it becomes for classification. As an
instance: Owen, in speaking of the dugong, says, "The generative
organs being those which are most remotely related to the habits and
food of an animal, I have always regarded as affording very clear
indications of its true affinities. We are least likely in the
modifications of these organs to mistake a merely adaptive for an
essential character." So with plants, how remarkable it is that the
organs of vegetation, on which their whole life depends, are of little
signification, excepting in the first main divisions; whereas the
organs of reproduction, with their product the seed, are of paramount
importance!

We must not, therefore, in classifying, trust to resemblances in parts
of the organisation, however important they may be for the welfare of
the being in relation to the outer world. Perhaps from this cause it
has partly arisen, that almost all naturalists lay the greatest stress
on resemblances in organs of high vital or physiological importance.
No doubt this view of the classificatory importance of organs which
are important is generally, but by no means always, true. But their
importance for classification, I believe, depends on their greater
constancy throughout large groups of species; and this constancy
depends on such organs having generally been subjected to less change
in the adaptation of the species to their conditions of life. That the
mere physiological importance of an organ does not determine its
classificatory value, is almost shown by the one fact, that in allied
groups, in which the same organ, as we have every reason to suppose,
has nearly the same physiological value, its classificatory value is
widely different. No naturalist can have worked at any group without
being struck with this fact; and it has been most fully acknowledged
in the writings of almost every author. It will suffice to quote the
highest authority, Robert Brown, who in speaking of certain organs in
the Proteaceae, says their generic importance, "like that of all their
parts, not only in this but, as I apprehend, in every natural family,
is very unequal, and in some cases seems to be entirely lost." Again
in another work he says, the genera of the Connaraceae "differ in
having one or more ovaria, in the existence or absence of albumen, in
the imbricate or valvular aestivation. Any one of these characters
singly is frequently of more than generic importance, though here even
when all taken together they appear insufficient to separate Cnestis
from Connarus." To give an example amongst insects, in one great
division of the Hymenoptera, the antennae, as Westwood has remarked,
are most constant in structure; in another division they differ much,
and the differences are of quite subordinate value in classification;
yet no one probably will say that the antennae in these two divisions
of the same order are of unequal physiological importance. Any number
of instances could be given of the varying importance for
classification of the same important organ within the same group of
beings.

Again, no one will say that rudimentary or atrophied organs are of
high physiological or vital importance; yet, undoubtedly, organs in
this condition are often of high value in classification. No one will
dispute that the rudimentary teeth in the upper jaws of young
ruminants, and certain rudimentary bones of the leg, are highly
serviceable in exhibiting the close affinity between Ruminants and
Pachyderms. Robert Brown has strongly insisted on the fact that the
rudimentary florets are of the highest importance in the
classification of the Grasses.

Numerous instances could be given of characters derived from parts
which must be considered of very trifling physiological importance,
but which are universally admitted as highly serviceable in the
definition of whole groups. For instance, whether or not there is an
open passage from the nostrils to the mouth, the only character,
according to Owen, which absolutely distinguishes fishes and
reptiles--the inflection of the angle of the jaws in Marsupials--the
manner in which the wings of insects are folded--mere colour in
certain Algae--mere pubescence on parts of the flower in grasses--the
nature of the dermal covering, as hair or feathers, in the Vertebrata.
If the Ornithorhynchus had been covered with feathers instead of hair,
this external and trifling character would, I think, have been
considered by naturalists as important an aid in determining the
degree of affinity of this strange creature to birds and reptiles, as
an approach in structure in any one internal and important organ.

The importance, for classification, of trifling characters, mainly
depends on their being correlated with several other characters of
more or less importance. The value indeed of an aggregate of
characters is very evident in natural history. Hence, as has often
been remarked, a species may depart from its allies in several
characters, both of high physiological importance and of almost
universal prevalence, and yet leave us in no doubt where it should be
ranked. Hence, also, it has been found, that a classification founded
on any single character, however important that may be, has always
failed; for no part of the organisation is universally constant. The
importance of an aggregate of characters, even when none are
important, alone explains, I think, that saying of Linnaeus, that the
characters do not give the genus, but the genus gives the characters;
for this saying seems founded on an appreciation of many trifling
points of resemblance, too slight to be defined. Certain plants,
belonging to the Malpighiaceae, bear perfect and degraded flowers; in
the latter, as A. de Jussieu has remarked, "the greater number of the
characters proper to the species, to the genus, to the family, to the
class, disappear, and thus laugh at our classification." But when
Aspicarpa produced in France, during several years, only degraded
flowers, departing so wonderfully in a number of the most important
points of structure from the proper type of the order, yet M. Richard
sagaciously saw, as Jussieu observes, that this genus should still be
retained amongst the Malpighiaceae. This case seems to me well to
illustrate the spirit with which our classifications are sometimes
necessarily founded.