Project Gutenberg''''s Facts and Arguments for Darwin, by Fritz Muller pot

If itwas possible upon the foundation and withthe aid of the Darwinian theory, to show in what sequence the various smaller andlarger circles had separated from the common fundamental fo

Project Gutenberg's Facts and Argumentsfor Darwin, by Fritz Muller

Copyright laws are changing all over theworld Be sure to check the copyrightlaws for your country before downloading

or redistributing this or any other ProjectGutenberg eBook

This header should be the first thing seenwhen viewing this Project Gutenberg file.Please do not remove it Do not change oredit the header without written

permission

Please read the "legal small print," andother information about the eBook andProject Gutenberg at the bottom of thisfile Included is important information

about your specific rights and restrictions

in how the file may be used You can alsofind out about how to make a donation toProject Gutenberg, and how to get

Release Date: September, 2004 [EBook

#6475] [Yes, we are more than one yearahead of schedule] [This file was firstposted on December 19, 2002]

Edition: 10

Language: English

*** START OF THE PROJECT

GUTENBERG EBOOK FACTS ANDARGUMENTS FOR DARWIN ***

Produced by Sue Asscher

asschers@bigpond.com

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 ROUNDTHE WORLD; BEING A JOURNAL OFRESEARCHES INTO THE NATURALHISTORY AND GEOLOGY OF

COUNTRIES VISITED Post 8vo 9shillings

THE ORIGIN OF SPECIES, BY MEANS

OF NATURAL SELECTION; OR, THEPRESERVATION OF FAVOUREDRACES IN THE STRUGGLE FOR LIFE.WOODCUTS Post 8vo 15 shillings

THE VARIOUS CONTRIVANCES BYWHICH BRITISH AND FOREIGN

ORCHIDS ARE

FERTILISED BY INSECTS, AND ON

THE GOOD EFFECTS OF

INTERCROSSING

Woodcuts, Post 8vo 9 shillings

THE VARIATION OF ANIMALS ANDPLANTS UNDER DOMESTICATION.Illustrations 2 volumes, 8vo 28 shillings

TRANSLATOR'S PREFACE.

My principal reason for undertaking thetranslation of Dr Fritz Muller's admirablework on the Crustacea, entitled 'Fur

Darwin,' was that it was still, althoughpublished as long ago as 1864, and highlyesteemed by the author's scientific

countrymen, absolutely unknown to a greatnumber of English naturalists, includingsome who have occupied themselves more

or less specially with the subjects of

which it treats It possesses a value quiteindependent of its reference to

Darwinism, due to the number of highlyinteresting and important facts in the

natural history and particularly the

developmental history of the Crustacea,which its distinguished author, himself anunwearied and original investigator ofthese matters, has brought together in it

To a considerable section of Englishnaturalists the tone adopted by the author

in speaking of one of the greatest of theirnumber will be a source of much

gratification

In granting his permission for the

translation of his little book, Dr FritzMuller kindly offered to send some

emendations and additions to certain parts

of it His notes included many corrections

of printers' errors, some of which wouldhave proved unintelligible without his aid,some small additions and notes whichhave been inserted in their proper places,and two longer pieces, one forming afootnote near the close of Chapter 11, theother at the end of Chapter 12, describingthe probable mode of evolution of theRhizocephala from the Cirripedia

Of the execution of the translation I willsay but little My chief object in this, as inother 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 Muller'sGerman does not submit itself to suchtreatment very readily, I must beg his andthe reader's indulgence for any

imperfections arising from this cause

W.S.D.

LONDON, 15TH 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 themone against the other Their object is

simply to indicate a few facts favourable

to this theory, collected upon the sameSouth American ground, on which, asDarwin tells us, the idea first occurred tohim of devoting his attention to "the origin

of species,—that mystery of mysteries."

It is only by the accumulation of new andvaluable material that the controversy willgradually be brought into a state fit forfinal decision, and this appears to be forthe present of more importance than arepeated analysis of what is already

before us Moreover, it is but fair to leave

it to Darwin himself at first to beat off theattacks of his opponents from the splendid

structure which he has raised with such amaster-hand.

CHAPTER 4 SEXUAL PECULIARITIES AND DIMORPHISM.

CHAPTER 5 RESPIRATION IN LAND CRABS.

CHAPTER 6 STRUCTURE OF THE HEART

CHAPTER 9 DEVELOPMENTAL HISTORY

OF ENTOMOSTRACA, CIRRIPEDES, AND RHIZOCEPHALA.

CHAPTER 10 ON THE PRINCIPLES OF

of the views developed in it, namely, toattempt apply them as specially as

possible to some particular group of

animals such an attempt to establish agenealogical tree, whether for the families

of a class, the genera of a large family, orfor the species of an extensive genus, and

to produce pictures as complete and

intelligible as possible of the commonancestors of the various smaller and largercircles, might furnish a result in threedifferent ways

1 In the first place, Darwin's suppositionswhen 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 theirdetailed application at every step, and thatthese, by their cumulative force, wouldentirely destroy the suppositions fromwhich they proceeded, even though thedeductions derived from each particularcase might possess little of the

unconditional nature of mathematical

proof

2 Secondly, the attempt might be

successful to a greater or less extent If itwas possible upon the foundation and withthe aid of the Darwinian theory, to show

in what sequence the various smaller andlarger circles had separated from the

common fundamental form and from eachother, in what sequence they had acquired

the peculiarities which now characterisethem, and what transformations they hadundergone in the lapse of ages,—if theestablishment of such a genealogical tree,

of a primitive history of the group underconsideration, free from internal

contradictions, was possible,—then thisconception, the more completely it took upall the species within itself, and the moredeeply it enabled us to descend into thedetails of their structure, must in the sameproportion bear in itself the warrant of itstruth, and the more convincingly prove thatthe foundation upon which it is built is noloose sand, and that it is more than merely

"an intellectual dream."

3 In the third place, however, it waspossible, and this could not but appear,

prima facie, the most probable case, thatthe attempt might be frustrated by thedifficulties standing in its way, withoutsettling the question, either way, in aperfectly satisfactory manner But if itwere only possible in this way to arrivefor 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, Ihad in the first place to decide upon someparticular class The choice was

necessarily limited to those the chiefforms of which were easily to be obtainedalive in some abundance The Crabs andMacrurous Crustacea, the Stomapoda, the

Diastylidae, the Amphipoda and Isopoda,the Ostracoda and Daphnidae, the

Copepoda and Parasita, the Cirripedesand Rhizocephala of our coast,

representing the class of Crustacea withthe deficiency only of the Phyllopoda andXiphosura, furnished a long and varied,and at the same time intimately connectedseries, such as was at my command in noother class But even independently of thiscircumstance the selection of the

Crustacea could hardly have been

doubtful Nowhere else, as has alreadybeen indicated by various writers, is thetemptation stronger to give to the

expressions "relationship, productionfrom a common fundamental form," andthe 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 scarcelyadmitting of a figurative meaning, of theirarrest of development by parasitism, as ifthe transformation of species were a

matter of course It would certainly neverappear to any one to be a pastime worthy

of the Deity, to amuse himself with thecontrivance of these marvellous

cripplings, and so they were supposed tohave fallen by their own fault, like Adam,from their previous state of perfection

That a great part of the larger and smallergroups 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 Acalephae, allthe attempted arrangements could only beconsidered preliminary revisions Theseundisplaceable groups, like the sharplymarked forms of the hard, many-jointeddermal framework, were not only

important as safe starting points and

supports, but were also of the highestvalue as inflexible barriers in a problem

in which, from its very nature, fancy mustfreely unfold her wings

When I thus began to study our Crustaceamore closely from this new stand-point ofthe Darwinian theory,—when I attempted

to bring their arrangements into the form

of a geological tree, and to form someidea of the probable structure of their

ancestors,—I speedily saw (as indeed Iexpected) that it would require years ofpreliminary work before the essentialproblem could be seriously handled Theextant systematic works generally laidmore weight upon the characters

separating the genera, families and orders,than upon those which unite the members

of each group, and consequently oftenfurnished but little employable material.But above all things a thorough knowledge

of development was indispensable, andevery one knows how imperfect is ourpresent knowledge of this subject Theexisting 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 byfamily, and frequently genus by genus—nay, sometimes, as in the case of Peneus,even species by species; and becausethese investigations, in themselves

troublesome and tedious, often depend fortheir success upon a lucky chance

But although the satisfactory completion ofthe "Genealogical tree of the Crustacea"appeared to be an undertaking for whichthe strength and life of an individual

would hardly suffice, even under morefavourable circumstances than could bepresented by a distant island, far removedfrom the great market of scientific life, farfrom libraries and museums—

nevertheless its practicability became

daily less doubtful in my eyes, and freshobservations daily made me more

favourably inclined towards the

Darwinian theory

In determining to state the argumentswhich I derived from the consideration ofour Crustacea in favour of Darwin's

views, and which (together with moregeneral considerations and observations

in other departments), essentially aided inmaking the correctness of those viewsseem more and more palpable to me, I amchiefly influenced by an expression ofDarwin's: "Whoever," says he ('Origin ofSpecies' page 482), "is led to believe thatspecies are mutable, will do a good

service by conscientiously expressing hisconviction." 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 givingexpression in words to the thanks which Ifeel most deeply to be due from me toDarwin for the instructions and

suggestions for which I am so deeplyindebted to his book Accordingly I throwthis sand-grain with confidence into thescale against "the load of prejudice bywhich this subject is overwhelmed,"without troubling myself as to whether thepriests of orthodox science will reckon

me amongst dreamers and children inknowledge of the laws of nature

CHAPTER 2 THE SPECIES OF

MELITA.

A false supposition, when the

consequences proceeding from it arefollowed further and further, will sooner

or later lead to absurdities and palpablecontradictions During the period of

tormenting doubt—and this was by nomeans a short one—when the pointer ofthe scales oscillated before me in perfectuncertainty between the pro and the con,and when any fact leading to a quick

decision would have been most welcome

to me, I took no small pains to detect somesuch contradictions among the inferences

as to the class of Crustacea furnished bythe Darwinian theory But I found none,either then, or subsequently Those which

I thought I had found were dispelled oncloser consideration, or actually becameconverted into supports for Darwin's

Nor, so far as I am aware, have any of theNECESSARY consequences of Darwin'shypotheses been proved by any one else,

to stand in clear and irreconcilable

contradiction And yet, as the most

profound students of the animal kingdomare amongst Darwin's opponents, it wouldseem that it ought to have been an easymatter for them to crush him long sincebeneath a mass of absurd and

contradictory inferences, if any such were

to be drawn from his theory To this want

of demonstrated contradictions I think wemay ascribe just the same importance inDarwin's favour, that his opponents haveattributed to the absence of demonstratedintermediate forms between the species of

the various strata of the earth.

Independently of the reasons which

Darwin gives for the preservation of suchintermediate forms being only exceptional,this last mentioned circumstance will not

be regarded as of very great significance

by any one who has traced the

development of an animal upon larvaefished from the sea, and had to seek invain for months, and even years, for thosetransitional forms, which he neverthelessknew to be swarming around him in

thousands

A few examples may show how

contradictions might come forth as

necessary results of the Darwinian

hypotheses

It seems to be a necessity for all crabswhich remain for a long time out of thewater (but why is of no consequence to ushere), that air shall penetrate from behindinto the branchial cavity Now thesecrabs, which have become more or lessestranged from the water, belong to themost different families—the Raninidae(Ranina), Eriphinae (Eriphia gonagra),Grapsoidae (Aratus, Sesarma, etc.),Ocypodidae (Gelasimus, Ocypoda), etc.,and the separation of these families mustdoubtless be referred to a much earlierperiod than the habit of leaving the waterdisplayed by some of their members Thearrangements connected with aerial

respiration, therefore, could not be

inherited from a common ancestor, andcould scarcely be accordant in their

construction If there were any such

accordance not referable to accidentalresemblance among them, it would have to

be laid in the scale as evidence against thecorrectness of Darwin's views I shallshow hereafter how in this case the result,far from presenting such contradictions,was rather in the most complete harmonywith what might be predicted from

Darwin's theory

(FIGURE 1 Melita exilii n sp., male,enlarged five times The large branchiallamellae are seen projecting between thelegs.)

A second example.—We are alreadyacquainted with four species of Melita(M valida, setipes, anisochir, and

Fresnelii), and I can add a fifth (Figure 1),

in which the second pair of feet bearsupon one side a small hand of the usualstructure, and on the other an enormousclasp-forceps This want of symmetry issomething so unusual among the

Amphipoda, and the structure of the forceps differs so much from what is seenelsewhere in this order, and agrees soclosely in the five species, that one mustunhesitatingly regard them as having

clasp-sprung from common ancestors belonging

to them alone among known species Butone of these species, M Fresnelii,

discovered by Savigny, in Egypt, is said

to want the secondary flagellum of theanterior antennae, which occurs in theothers From the trustworthiness of allSavigny's works there can scarcely be a

doubt as to the correctness of this

statement Now, if the presence or

absence of the secondary flagellum

possessed the significance of a distinctivegeneric character, which is usually

ascribed to it, or if there were other

important differences between MelitaFresnelii and the other species above-mentioned, which would make it seemnatural to separate M Fresnelii as a

distinct genus, and to leave the othersunited with the rest of the species ofMelita—that is to say, in the sense of theDarwinian theory, if we assume that allthe other Melitae possessed commonancestors, which were not at the sametime the ancestors of M Fresnelii—thiswould stand in contradiction to the

conclusion, derived from the structure of

the clasp-forceps, that M Fresnelii andthe four other species above-mentionedpossessed common ancestors, which werenot also the ancestors of the remainingspecies of Melita It would follow:—

1 From the structure of the clasp-forceps:that M exilii, etc and M Fresnelii wouldbranch off together from a stem whichbranches off from M palmata

2 From the presence or absence of thesecondary flagellum: that M palmata, etc.and M exilii, etc would branch off

together from a stem which branches offfrom M Fresnelii

As, in the first case, among the Crabs, atypical agreement of arrangements

produced independently of each otherwould have been a very suspicious

circumstance for Darwin's theory, so also,

in the second, would any difference moreprofound than that of very nearly alliedspecies Now it seems to me that the

secondary flagellum can by no meansfurnish a reason for doubting the closerelationship of M Fresnelii to M exilii,etc., which is indicated by the peculiarstructure of the unpaired clasp-forceps Inthe first place we must consider the

possibility that the secondary flagellum,which is not always easy to detect, mayonly have been overlooked by Savigny, asindeed Spence Bate supposes to havebeen the case If it is really deficient itmust be remarked that I have found it inspecies of the genera Leucothoe,

Cyrtophium and Amphilochus, in whichgenera it was missed by Savigny, Danaand Spence Bate—that a species proved

by the form of the Epimera (Coxae Sp B.)

of the caudal feet (uropoda Westw.), etc.,

to be a true Amphithoe* possesses it (* Iaccept this and all the other genera ofAmphipoda here mentioned, with thelimits given to them by Spence Bate

('Catalogue of Amphipodous Crustacea').)

—that in many species of Cerapus it isreduced to a scarcely perceptible

rudiment—nay, that it is sometimes

present in youth and disappears (althoughperhaps not without leaving some trace) atmaturity, as was found by Spence Bate to

be the case in Acanthonotus Owenii andAtylus carinatus, and I can affirm withregard to an Atylus of these seas,

remarkable for its plumose branchiae—and that from all this, at the present daywhen the increasing number of knownAmphipoda and the splitting of them intonumerous genera thereby induced,

compels us to descend to very minutedistinctive characters, we must

nevertheless hesitate before employing thesecondary flagellum as a generic

character The case of Melita Fresneliitherefore cannot excite any doubts as toDarwin's theory

CHAPTER 3 MORPHOLOGY OF CRUSTACEA—NAUPLIUS-LARVAE.

If the absence of contradictions among theinferences deduced from them for a

narrow and consequently easily surveyeddepartment must prepossess us in favour

of Darwin's views, it must be welcomed

as a positive triumph of his theory if reaching conclusions founded upon itshould SUBSEQUENTLY be confirmed

far-by facts, the existence of which science, inits previous state, by no means allowed us

to suspect From many results of this kindupon which I could report, I select asexamples, two, which were of particularimportance to me, and relate to

discoveries the great significance of

which in the morphology and

classification of the Crustacea will not bedenied even by the opponents of Darwin.Considerations upon the developmentalhistory of the Crustacea had led me to the

conclusion that, if the higher and lowerCrustacea were at all derivable fromcommon progenitors, the former also mustonce have passed through Nauplius-likeconditions Soon afterwards I discoveredNaupliiform larvae of Shrimps ('Archivfur Naturgeschichte' 1860 1 page 8), and Imust admit that this discovery gave me thefirst decided turn in Darwin's favour.

(FIGURE 2 Tanais dubius (?) Kr female,magnified 25 times, showing the orifice ofentrance (x) into the cavity overarched bythe carapace, in which an appendage ofthe second pair of maxillae (f) plays Onfour feet (i, k, l, m) are the rudiments ofthe lamellae which subsequently form thebrood-cavity.)

The similar number of segments*

occurring in the Crabs and Macrura,

Amphipoda and Isopoda, in which the lastseven segments are always different fromthe preceding ones in the appendages withwhich they are furnished, could only beregarded as an inheritance from the sameancestors

(* Like Claus I do not regard the eyes ofthe Crustacea as limbs, and thereforeadmit no ocular segment; on the other hand

I count in the median piece of the tail, towhich the character of a segment is oftendenied In opposition to its interpretation

as a segment of the body, only the want oflimbs can be cited; in its favour we havethe relation of the intestine, which usuallyopens in this piece, and sometimes even