Produced by Sue Asscher
Facts and Arguments for Darwin
by Fritz Müller
WITH ADDITIONS BY THE AUTHOR
Translated from the German
by W. S. DALLAS, F.L.S.
Assistant Secretary to the Geological Society of London
WITH ILLUSTRATIONS
LONDON:
JOHN MURRAY, ALBEMARLE
STREET
1869
Mr. DARWIN'S WORKS
A NATURALIST’S VOYAGE ROUND THE WORLD; being a Journal of Researches
into the Natural History and Geology of Countries visited. Post 8vo. 9
shillings.
THE ORIGIN OF SPECIES, BY MEANS OF NATURAL SELECTION; or, the Preservation
of Favoured Races in the Struggle for Life. Woodcuts. Post 8vo. 15
shillings.
THE VARIOUS CONTRIVANCES BY WHICH BRITISH AND FOREIGN ORCHIDS ARE
FERTILISED BY INSECTS, and on the Good Effects of Intercrossing. Woodcuts,
Post 8vo. 9 shillings.
THE VARIATION OF ANIMALS AND PLANTS UNDER DOMESTICATION. Illustrations. 2
volumes, 8vo. 28 shillings.
Contents
TRANSLATOR’S PREFACE
AUTHOR’S PREFACE
Chapter 1. Introductory.
Chapter 2. The Species of Melita.
Chapter 3. Morphology of Crustacea.
Chapter 4. Sexual Peculiarities and Dimorphism.
Chapter 5. Respiration in Land Crabs.
Chapter 6. Structure of the Heart in Edriophthalma.
Chapter 7. Developmental History of Podophthalma.
Chapter 8. Developmental History of Edriophthalma.
Chapter 9. Developmental History of Entomostraca, Cirripedes, and Rhizocephala.
Chapter 10. On the Principles of Classification.
Chapter 11. On the Progress of Evolution.
Chapter 12. Progress of Evolution in Crustacea.
Index
TRANSLATOR’S PREFACE
My principal reason for undertaking the translation of Dr. Fritz
Müller’s admirable work on the Crustacea, entitled ‘Für Darwin,’ was
that it was still, although published as long ago as 1864, and highly
esteemed by the author’s scientific countrymen, absolutely unknown to a
great number of English naturalists, including some who have occupied
themselves more or less specially with the subjects of which it treats.
It possesses a value quite independent of its reference to Darwinism,
due to the number of highly interesting and important facts in the
natural history and particularly the developmental history of the
Crustacea, which its distinguished author, himself an unwearied and
original investigator of these matters, has brought together in it. To
a considerable section of English naturalists the tone adopted by the
author in speaking of one of the greatest of their number will be a
source of much gratification.
In granting his permission for the translation of his little book, Dr.
Fritz Müller kindly offered to send some emendations and additions to
certain parts of it. His notes included many corrections of printers'
errors, some of which would have proved unintelligible without his aid,
some small additions and notes which have been inserted in their proper
places, and two longer pieces, one forming a footnote near the close of
Chapter 11, the other at the end of Chapter 12, describing the probable
mode of evolution of the Rhizocephala from the Cirripedia.
Of the execution of the translation I will say but little. My chief
object in this, as in other cases, has been to furnish, as nearly as
possible, a literal version of the original, regarding mere elegance of
expression as of secondary importance in a scientific work. As much of
Dr. Müller’s German does not submit itself to such treatment very
readily, I must beg his and the reader’s indulgence for any
imperfections arising from this cause.
W.S.D.
LONDON, 15_th February_, 1869.
AUTHOR’S PREFACE
It is not the purpose of the following pages to discuss once more the
arguments deduced for and against Darwin’s theory of the origin of
species, or to weigh them one against the other. Their object is simply
to indicate a few facts favourable to this theory, collected upon the
same South American ground, on which, as Darwin tells us, the idea
first occurred to him of devoting his attention to “the origin of
species,—that mystery of mysteries.”
It is only by the accumulation of new and valuable material that the
controversy will gradually be brought into a state fit for final
decision, and this appears to be for the present of more importance
than a repeated analysis of what is already before us. Moreover, it is
but fair to leave it to Darwin himself at first to beat off the attacks
of his opponents from the splendid structure which he has raised with
such a master-hand.
F.M.
DESTERRO, 7_th September_, 1863.
HISTORY OF CRUSTACEA
CHAPTER I.
INTRODUCTORY.
When I had read Charles Darwin's book ‘On the Origin of Species,’ it
seemed to me that there was one mode, and that perhaps the most
certain, of testing the correctness of the views developed in it,
namely, to attempt to apply them as specially as possible to some
particular group of animals. such an attempt to establish a
genealogical tree, whether for the families of a class, the genera of a
large family, or for the species of an extensive genus, and to produce
pictures as complete and intelligible as possible of the common
ancestors of the various smaller and larger circles, might furnish a
result in three different ways.
1. In the first place, Darwin’s suppositions when thus applied might
lead to irreconcilable and contradictory conclusions, from which the
erroneousness of the suppositions might be inferred. If Darwin’s
opinions are false, it was to be expected that contradictions would
accompany their detailed application at every step, and that these, by
their cumulative force, would entirely destroy the suppositions from
which they proceeded, even though the deductions derived from each
particular case might possess little of the unconditional nature of
mathematical proof.
2. Secondly, the attempt might be successful to a greater or less
extent. If it was possible upon the foundation and with the aid of the
Darwinian theory, to show in what sequence the various smaller and
larger circles had separated from the common fundamental form and from
each other, in what sequence they had acquired the peculiarities which
now characterise them, and what transformations they had undergone in
the lapse of ages,—if the establishment of such a genealogical tree, of
a primitive history of the group under consideration, free from
internal contradictions, was possible,—then this conception, the more
completely it took up all the species within itself, and the more
deeply it enabled us to descend into the details of their structure,
must in the same proportion bear in itself the warrant of its truth,
and the more convincingly prove that the foundation upon which it is
built is no loose sand, and that it is more than merely “an
intellectual dream.”
3. In the third place, however, it was possible, and this could not but
appear, _primâ facie_, the most probable case, that the attempt might
be frustrated by the difficulties standing in its way, without settling
the question, either way, in a perfectly satisfactory manner. But if it
were only possible in this way to arrive for oneself at a moderately
certain independent judgment upon a matter affecting the highest
questions so deeply, even this alone could not but be esteemed a great
gain.
Having determined to make the attempt, I had in the first place to
decide upon some particular class. The choice was necessarily limited
to those the chief forms of which were easily to be obtained alive in
some abundance. The Crabs and Macrurous Crustacea, the Stomapoda, the
Diastylidæ, the Amphipoda and Isopoda, the Ostracoda and Daphnidæ, the
Copepoda and Parasita, the Cirripedes and Rhizocephala of our coast,
representing the class of Crustacea with the deficiency only of the
Phyllopoda and Xiphosura, furnished a long and varied, and at the same
time intimately connected series, such as was at my command in no other
class. But even independently of this circumstance the selection of the
Crustacea could hardly have been doubtful. Nowhere else, as has already
been indicated by various writers, is the temptation stronger to give
to the expressions “relationship, production from a common fundamental
form,” and the like, more than a mere figurative signification, than in
the case of the lower Crustacea. Among the parasitic Crustacea,
especially, everybody has long been accustomed to speak, in a manner
scarcely admitting of a figurative meaning, of their arrest of
development by parasitism, as if the transformation of species were a
matter of course. It would certainly never appear to any one to be a
pastime worthy of the Deity, to amuse himself with the contrivance of
these marvellous cripplings, and so they were supposed to have fallen
by their own fault, like Adam, from their previous state of perfection.
That a great part of the larger and smaller groups into which this
class is divided, might be regarded as satisfactorily established, was
a further advantage not to be undervalued; whilst in two other classes
with which I was familiar, namely, the Annelida and Acalephæ, all the
attempted arrangements could only be considered preliminary revisions.
These undisplaceable groups, like the sharply marked forms of the hard,
many-jointed dermal framework, were not only important as safe starting
points and supports, but were also of the highest value as inflexible
barriers in a problem in which, from its very nature, fancy must freely
unfold her wings.
When I thus began to study our Crustacea more closely from this new
stand-point of the Darwinian theory,—when I attempted to bring their
arrangements into the form of a geological tree, and to form some idea
of the probable structure of their ancestors,—I speedily saw (as indeed
I expected) that it would require years of preliminary work before the
essential problem could be seriously handled. The extant systematic
works generally laid more weight upon the characters separating the
genera, families and orders, than upon those which unite the members of
each group, and consequently often furnished but little employable
material. But above all things a thorough knowledge of development was
indispensable, and every one knows how imperfect is our present
knowledge of this subject. The existing deficiencies were the more
difficult to supply, because, as Van Beneden remarks with regard to the
Decapoda, from the often incredible difference in the development of
the most nearly allied forms, these must be separately studied—usually
family by family, and frequently genus by genus—nay, sometimes, as in
the case of _Penëus_, even species by species; and because these
investigations, in themselves troublesome and tedious, often depend for
their success upon a lucky chance.
But although the satisfactory completion of the “Genealogical tree of
the Crustacea” appeared to be an undertaking for which the strength and
life of an individual would hardly suffice, even under more favourable
circumstances than could be presented by a distant island, far removed
from the great market of scientific life, far from libraries and
museums—nevertheless its practicability became daily less doubtful in
my eyes, and fresh observations daily made me more favourably inclined
towards the Darwinian theory.
In determining to state the arguments which I derived from the
consideration of our Crustacea in favour of Darwin’s views, and which
(together with more general considerations and observations in other
departments), essentially aided in making the correctness of those
views seem more and more palpable to me, I am chiefly influenced by an
expression of Darwin’s: “Whoever,” says he (‘Origin of Species’ page
482), “is led to believe that species are mutable, will do a good
service by conscientiously expressing his conviction.” To the desire
expressed in these words I respond, for my own part, with the more
pleasure, as this furnishes me with an opportunity of publicly giving
expression in words to the thanks which I feel most deeply to be due
from me to Darwin for the instructions and suggestions for which I am
so deeply indebted to his book. Accordingly I throw this sand-grain
with confidence into the scale against “the load of prejudice by which
this subject is overwhelmed,” without troubling myself as to whether
the priests of orthodox science will reckon me amongst dreamers and
children in knowledge of the laws of nature.