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Chapter 12: 1843-1846: Aet. 36-39.
- Completion of fossil fishes.
-- followed by fossil fishes of the old Red Sandstone.
-- review of the later work.
-- identification of fishes by the skull.
-- renewed correspondence with Prince Canino about journey to the United States.
-- change of plan owing to the interest of the King of Prussia in the expedition.
-- correspondence between Professor Sedgwick and Agassiz on development theory.
-- final scientific work in Neuchatel and Paris.
-- publication of ‘Systeme Glaciaire.’
-- short stay in England.
-- sails for United States.
In 1843 the ‘Recherches sur les Poissons Fossiles’ was completed, and fast upon its footsteps, in 1844, followed the author's ‘Monograph on the
Fossil Fishes of the
Old Red Sandstone, or the
Devonian System of
Great Britain and
Russia,’ a large quarto volume of text, accompanied by forty-one plates.
Nothing in his paleontological studies ever interested
Agassiz more than this curious fauna of the Old Red, so strange in its combinations that even well-informed naturalists had attributed its fossil remains to various classes of the animal kingdom in turn, and, indeed, long
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remained in doubt as to their true nature.
Agassiz says himself in his Preface: ‘I can never forget the impression produced upon me by the sight of these creatures, furnished with appendages resembling wings, yet belonging, as I had satisfied myself, to the class of fishes.
Here was a type entirely new to us, about to renter (for the first time since it had ceased to exist) the series of beings; nor could anything, thus far revealed from extinct creations, have led us to anticipate its existence.
So true is it that observation alone is a safe guide to the laws of development of organized beings, and that we must be on our guard against all those systems of transformation of species so lightly invented by the imagination.’
The author goes on to state that the discovery of these fossils was mainly due to
Hugh Miller, and that his own work had been confined to the identification of their character and the determination of their relations to the already known fossil fishes.
This work, upon a type so extraordinary, implied, however, innumerable and reiterated comparisons, and a minute study of the least fragments of the remains which could be procured.
The materials were chiefly obtained in
Scotland; but
Sir Roderick Murchison also contributed his own
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collection from the Old Red of
Russia, and various other specimens from the same locality.
Not only on account of their peculiar structure were the fishes of the Old Red interesting to
Agassiz, but also because, with this fauna, the vertebrate type took its place for the first time in what were then supposed to be the most ancient fossiliferous beds.
When
Agassiz first began his researches on fossil fishes, no vertebrate form had been discovered below the coal.
The occurrence of fishes in the Devonian and Silurian beds threw the vertebrate type back, as he believed, into line with all the invertebrate classes, and seemed to him to show that the four great types of the animal kingdom, Radiates, Mollusks, Articulates, and Vertebrates, had appeared together.
1 ‘It is henceforth demonstrated,’ says
Agassiz, ‘that the fishes were included in the plan of the first organic combinations which made the point of departure for all the living inhabitants of our globe in the series of time.’
In his opinion this simultaneity of appearance, as well as the richness and variety displayed by invertebrate classes from the beginning,
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made it
2 ‘impossible to refer the first inhabitants of the earth to a few stocks, subsequently differentiated under the influence of external conditions of existence.’ . . . He adds:
3 ‘I have elsewhere presented my views upon the development through which the successive creations have passed during the history of our planet.
But what I wish to prove here, by a careful discussion of the facts reported in the following pages, is the truth of the law now so clearly demonstrated in the series of vertebrates, that the successive creations have undergone phases of development analogous to those of the embryo in its growth and similar to the gradations shown by the present creation in the ascending series, which it presents as a whole.
One may consider it as henceforth proved that the embryo of the fish during its development, the class of fishes as it at present exists in its numerous families, and the type of fish in its planetary history, exhibit analogous phases through which one may follow the same creative thought like a guiding thread in the study of the connection
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between organized beings.’
Following this comparison closely, he shows how the early embryonic condition of the present fishes is recalled by the general disposition of the fins in the fishes of the
Old Red Sandstone, and especially by the caudal fin, making the unevenly lobed tail, so characteristic of these ancient forms.
This so called heterocercal tail is only known to exist, as a permanent adult feature, in the sturgeons of to-day.
The form of the head and the position of the mouth and eyes in the fishes of the Old Red were also shown to be analogous with embryonic phases of our present fishes.
From these analogies, and also from the ascendency of fishes as the only known vertebrate, and therefore as the highest type in those ancient deposits,
Agassiz considered this fauna as representing ‘the embryonic age of the reign of fishes;’ and he sums up his results in conclusion in the following words: ‘The facts, taken as a whole, seem to me to show, not only that the fishes of the Old Red constitute an independent fauna, distinct from those of other deposits, but that they also represent in their organization the most remarkable analogy with the first phases of embryonic development in the bony fishes of our epoch, and a no less
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marked parallelism with the lower degrees of certain types of the class as it now exists on the surface of the earth.’
It has been said by one of the biographers of
Agassiz,
4 in reference to this work upon the fishes of the
Old Red Sandstone: ‘It is difficult to understand why the results of these admirable researches, and of later ones made by him, did not in themselves lead him to support the theory of transformation, of which they seem the natural consequence.’
It is true that except for the frequent allusion to a creative thought or plan, this introduction to the Fishes of the Old Red might seem to be written by an advocate of the development theory rather than by its most determined opponent, so much does it deal with laws of the organic world, now used in support of evolution.
These comprehensive laws, announced by
Agassiz in his ‘Poissons Fossiles,’ and afterward constantly reiterated by him, have indeed been adopted by the writers on evolution, though with a wholly different interpretation.
No one saw more clearly than
Agassiz the relation which he first pointed out, between the succession of animals of the same type in time and the phases of their embryonic
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growth to-day, and he often said, in his lectures, ‘the history of the individual is the history of the type.’
But the coincidence between the geological succession, the embryonic development, the zoological gradation, and the geographical distribution of animals in the past and the present, rested, according to his belief, upon an intellectual coherence and not upon a material connection.
So, also, the variability, as well as the constancy, of organized beings, at once so plastic and so inflexible, seemed to him controlled by something more than the mechanism of selfadjust-ing forces.
In this conviction he remained unshaken all his life, although the development theory came up for discussion under so many various aspects during that time.
His views are now in the descending scale; but to give them less than their real prominence here would be to deprive his scientific career of its true basis.
Belief in a Creator was the keynote of his study of nature.
In summing up the comprehensive results of
Agassiz's paleontological researches, and especially of his ‘
Fossil Fishes,’
Arnold Guyot says:
5—
‘Whatever be the opinions which many
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may entertain as to the interpretation of some of these generalizations, the vast importance of these results of
Agassiz's studies may be appreciated by the incontestable fact, that nearly all the questions which modern paleontology has treated are here raised and in great measure solved.
They already form a code of general laws which has become a foundation for the geological history of the life-system, and which the subsequent investigations of science have only modified and extended, not destroyed.
Nowhere did the mind of
Agassiz show more power of generalization, more vigor, or more originality.
The discovery of these great truths is truly his work; he derived them immediately from nature by his own observations.
Hence it is that all his later zoological investigations tend to a common aim, namely, to give by farther studies, equally conscientious but more extensive, a broader and more solid basis to those laws which he had read in nature and which he had proclaimed at that early date in his immortal work, “ Poissons Fossiles.”
Let us not be astonished that he should have remained faithful to these views to the end of his life.
It is because he had
seen that he
believed, and such a faith is not easily shaken by new hypotheses.’
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. . .I write in all haste to ask for any address to which I can safely forward my report on the Sheppy fishes, so that they may arrive without fail in time for the meeting at
York.
Since my last letter I have made progress in this kind of research.
I have sacrificed all my duplicates of our present fishes to furnish skeletons.
I have prepared more than a hundred since I last wrote you, and I can now determine the family, and even the genus, simply by seeing the skull.
There remains nothing impossible now in the determination of fishes, and if I can obtain certain exotic genera, which I have not as yet, I can make an osteology of fishes as complete as that which we possess for the other classes of vertebrates.
Every family has its special type of skull.
All this is extremely interesting.
I have already corrected a mass of inaccurate identifications established upon external characters; and as for fossils, I have recognized and characterized seventeen new genera among the less perfect undetermined specimens you have sent me. Several families appear now for the first time among the fossils.
I have been able to
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determine to what family all the doubtful genera belong; indeed Sheppy will prove as rich in species as
Mont Bolca.
When you see your specimens again you will hardly recognize them, they are so changed; I have chiseled and cleaned them, until they are almost like anatomical preparations.
Try to procure as many more specimens as possible and send them to me. I cannot stir from
Neuchatel, now that I am so fully in the spirit of work, and besides it would be a useless expense. . . . You will receive with my report the three numbers which complete my monograph of the Fishes of the Old Red. I feel sure, in advance, that you will be satisfied with them. . . .
Tolly house,
Alness, Rossshire. September 15, 1844.
. . . I have only this day received your letter of the 6th, and I fear much you will scarcely receive this in time to make it available.
I shall not be able to reach
York for the commencement of the meeting, but hope to be there on Saturday, September 28th.
A parcel will reach me in the shortest possible time addressed
Sir P. Egerton, Donnington
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Rectory,
York.
I am delighted with the bright results of your comparison of the Sheppy fossils with recent forms.
You appear to have opened out an entirely new field of investigation, likely to be productive of most brilliant results.
Should any accident delay the arrival of your monograph for the
York meeting, I shall make a point of communicating to our scientific friends the contents of your letter, as I know they will rejoice to hear of the progress of fossil ichthyology in your masterly hands.
When next you come, I wish you could spend a few days here.
We are surrounded on all sides by the debris of the moraines of the ancient glaciers that descended the flank of
Ben Wyvis, and I think you would find much to interest you in tracing their relations.
We have also the Cromarty Fish-beds within a few miles, and many other objects of geological interest. . . . I shall see Lord Enniskillen at
York, and will tell him of your success.
We shall, of course, procure all the Sheppy fish we can either by purchase or exchange. . . .
The pressure of work upon his various publications detained
Agassiz at home during the summer of 1844.
For the first time he was
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unable to make one of the glacial party this year, but the work was carried on uninterruptedly, and the results reported to him. Meantime his contemplated journey to the
United States flitted constantly before him.
. . . Your idea of an illustrated American ichthyology is admirable.
But for that we ought to have with us an artist clever enough to paint fishes rapidly from the life.
Work but half done is no longer permissible in our days. . . . In this matter I think there is a justice due to
Rafinesque.
However poor his descriptions, he nevertheless first recognized the necessity of multiplying genera in ichthyology, and that at a time when the thing was far more difficult than now. Several of his genera have even the priority over those now accepted, and I think in the
United States it would be easier than elsewhere to find again a part of the materials on which he worked.
We must not neglect from this time forth to ask
Americans to put us in the way of extending this work throughout
North America.
If you accept me for your collaborator, I will at once do all that I can on my
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side to bring together notes and specimens.
I will write to several naturalists in the
United States, and tell them that as I am to accompany you on your voyage I should be glad to know in advance what they have done in ichthyology, so that we may be the better prepared to profit by our short sojourn in their country.
However, I will do nothing before having your directions, which, for the sake of the matter in hand, I should be glad to receive as early as possible. . . .
The next letter announces a new aspect of the projected journey.
In explanation, it should be said that finding
Agassiz might be prevented by his poverty from going, the prince had invited him to be his guest for a summer in the
United States.
. . . I have received an excellent piece of news from
Humboldt, which I hasten to share with you. I venture to believe that it will please you also. . . . . I had written to
Humboldt of our plans, and of your kind offer to take me with you to the
United States, telling him at the same time how much I regretted
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that I should be unable to visit the regions which attracted me the most from a geological point of view, and asking him if it would be possible to interest the king in this journey and obtain means from his majesty for a longer stay on the other side of the
Atlantic.
I have just received a delightful and most unexpected reply.
The king will grant me 15,000 francs for this object, so that I shall, in any event, be able to make the journey.
All the more do I desire to make it in your society, and I think by combining our forces we shall obtain more important results; but I am glad that I can do it without being a burden to you. Before answering
Humboldt, I am anxious to know whether your plans are definitely decided upon for this summer, and whether this arrangement suits you. . . .
The pleasant plan so long meditated was not to be fulfilled.
The prince was obliged to defer the journey and never accomplished it. This was a great disappointment to
Agassiz.
‘Am I then to go without you,’ he writes; ‘is this irrevocable?
If I were to defer my departure till September would it then be possible for you to leave
Rome?
It would be
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too delightful if we could make this journey together.
I wish also, before starting, to review everything that has been done of late in paleontology, zoology, and comparative anatomy, that I may, in behalf of all these sciences, take advantage of the circumstances in which I shall be placed. . . . Whatever befalls me, I feel that I shall never cease to consecrate my whole energy to the study of nature; its all powerful charm has taken such possession of me that I shall always sacrifice everything to it; even the things which men usually value most.’
Agassiz had determined, before starting on his journey, to complete all his unfinished works, and to put in order his correspondence and collections, including the vast amount of specimens sent him for identification or for his own researches.
The task of ‘setting his house in order’ for a change which, perhaps, he dimly felt to be more momentous than it seemed, proved long and laborious.
From all accounts, he performed prodigies of work, but the
winter and
spring passed, and the summer of 1845 found him still at his post.
Humboldt writes him not without anxiety lest his determination to complete all the tasks he had undertaken, including the Nomenclator,
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should involve him in endless delays and perplexities.
. . . Your Nomenclator frightens me with its double entries.
The Milky Way must have crossed your path, for you seem to be dealing with nebulae which you are trying to resolve into stars.
For pity's sake husband your strength.
You treat this journey as if it were for life.
As to finishing,—alas!
my friend, one does not finish.
Considering all that you have in your well-furnished brain beside your accumulated papers, half the contents of which you do not yourself know, your expression ‘aufraumen,’—to put in final order, is singularly inappropriate.
There will always remain some burdensome residue, —last things not yet accounted for. I beg you, then, not to abuse your strength.
Be content to finish only what seems to you nearest completion,—the most advanced of your work.
Your letter reached me, unaccompanied, however, by the books it announces.
They are to come, no doubt, in some other way. Spite of the demands made upon me by the continuation of my ‘Cosmos,’ I shall find
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time to read and profit by your introduction to the Old Red. I am inclined to sing hymns of praise to the Hyperboreans who have helped you in this admirable work.
What you say of the specific difference in vertical line and of the increased number of biological epochs is full of interest and wisdom.
No wonder you rebel against the idea that the
Baltic contains microscopic animals identical with those of the chalk!
I foresee, however, a new
battle of Waterloo between you and my friend
Ehrenberg, who accompanied me lately, just after the
Victoria festivals, to the volcanoes of the Eifel with Dechen.
Not an inch of ground without infusoria in those regions!
For Heaven's sake do not meddle with the infusoria before you have seen the
Canada Lakes and completed your journey.
Defer them till some more tranquil period of your life. . . . . I must close my letter with the hope that you will never doubt my warm affection.
Assuredly I shall find no fault with any course of lectures you may give in the new world, nor do I see the least objection to giving them for money.
You can thus propagate your favorite views and spread useful knowledge, while at the same time you will, by most honorable and praiseworthy means, provide additional funds for your traveling expenses. . . .
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The following correspondence with
Professor Adam Sedgwick is of interest, as showing his attitude and that of
Agassiz toward questions which have since acquired a still greater scientific importance.
my dear
Professor,—The British Association is to meet here about the middle of June, and I trust that the occasion will again bring you to
England and give me the great happiness of entertaining you in Trinity College.
Indeed, I wish very much to see you; for many years have now elapsed since I last had that pleasure.
May God long preserve your life, which has been spent in promoting the great ends of truth and knowledge!
Your great work on fossil fishes is now before me, and I also possess the first number of your monograph upon the fishes of the
Old Red Sandstone.
I trust the new numbers will follow the first in rapid succession.
I love now and then to find a resting-place; and your works always give me one.
The opinions of
Geoffroy St. Hilaire and his dark school seem to be gaining some ground in
England.
I
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detest them, because I think them untrue.
They shut out all argument from
design and all notion of a Creative
Providence, and in so doing they appear to me to deprive physiology of its life and strength, and language of its beauty and meaning.
I am as much offended in taste by the turgid mystical bombast of Geoffroy as I am disgusted by his cold and irrational materialism.
When men of his school talk of the elective affinity of organic types, I hear a jargon I cannot comprehend, and I turn from it in disgust; and when they talk of spontaneous generation and transmutation of species, they seem to me to try nature by an hypothesis, and not to try their hypothesis by nature.
Where are their facts on which to form an inductive truth?
I deny their starting condition.
‘Oh! but’ they reply, ‘we have progressive development in geology.’
Now, I allow (as all geologists must do) a
kind of
progressive development. For example, the first fish are below the reptiles; and the first reptiles older than man. I say, we have successive forms of animal life adapted to successive conditions (so far, proving design), and not derived in natural succession in the ordinary way of generation.
But if no single fact in actual nature allows
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us to suppose that the new species and orders were produced successively in the natural way, how did they begin?
I reply, by a way out of and above common known, material nature, and this way I call
creation. Generation and creation are two distinct ideas, and must be described by two distinct words, unless we wish to introduce utter confusion of thought and language.
In this view I think you agree with me; for I spoke to you on the subject when we met (alas,
ten years since!) at
Dublin.
Would you have the great kindness to give me your most valuable opinion on one or two points?
(1.) Is it possible, according to the known laws of actual nature, or is it probable, on any analogies of nature, that the vast series of fish, from those of the
Ludlow rock and the
Old Red Sandstone to those of our actual seas, lakes, and rivers, are derived from one common original low type, in the way of development and by propagation or natural breeding?
I should say,
no. But my knowledge is feeble and at second-hand.
Yours is strong and from the fountain-head.
(2.) Is the organic type of fish higher now than it was during the carboniferous period, when the Sauroids so much abounded?
If
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the progressive theory of Geoffroy be true, in his sense, each class of animals ought to be progressive in its organic type.
It appears to me that this is not true.
Pray tell me your own views on this point.
(3.) There are ‘
odd fish’ (as we say in jest) in the
Old Red Sandstone.
Do these so graduate into crustaceans as to form anything like such an organic link that one could, by generation, come naturally from the other?
I should say,
no, being instructed by your labors.
Again, allowing this, for the sake of argument, are there not much higher types of fish which are contemporaneous with the lower types (if, indeed, they be lower), and do not these nobler fish of the
Old Red Sandstone stultify the hypothesis of natural generative development?
(4.) Will you give me, in a few general words, your views of the scale occupied by the fish of the Old Red, considered as a natural group?
Are they so rudimentary as to look like abortions or creatures derived from some inferior class, which have not yet by development reached the higher type of fish?
Again, I should say,
no; but I long for an answer from a great authority like yours.
I am most anxious for a good general conception
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of the fish of the Old Red, with reference to some intelligible scale.
(5.) Lastly, is there the shadow of ground for supposing that by any natural generative development the Ichthyosaurians and other kindred forms of reptile have come from Sauroid, or any other type of fish?
I believe you will say, no. At any rate, the facts of geology lend no support to such a view, for the nobler forms of Reptile appear in strata below those in which the Ichthyosaurians, etc., are first seen.
But I must not trouble you with more questions.
Professor Whewell is now
Master of Trinity College.
We shall all rejoice to see you.
Ever, my dear
Professor, your most faithful and most grateful friend,
. . . I reproach myself for not acknowledging at once your most interesting letter of April 10th.
But you will easily understand that in the midst of the rush of work consequent upon my preparation for a journey of several years' duration I have not noticed the flight of time since I received it, until to-day,
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when the sight of the date fills me with confusion.
And yet, for years, I have not received a letter which has given me greater pleasure or moved me more deeply.
I have felt in it and have received from it that vigor of conviction which gives to all you say or write a virile energy, captivating alike to the listener or the reader.
Like you, I am pained by the progress of certain tendencies in the domain of the natural sciences; it is not only the arid character of this philosophy of nature (and by this I mean, not
natural philosophy, but the ‘Natur-philosophie’ of the Germans and French) which alarms me. I dread quite as much the exaggeration of religious fanaticism, borrowing fragments from science, imperfectly or not at all understood, and then making use of them to prescribe to scientific men what they are allowed to see or to find in Nature.
Between these two extremes it is difficult to follow a safe road.
The reason is, perhaps, that the domain of facts has not yet received a sufficiently general recognition, while traditional beliefs still have too much influence upon the study of the sciences.
Wishing to review such ideas as I had formed upon these questions, I gave a public course this winter upon the plan of creation
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as shown in the development of the animal kingdom.
I wish I could send it to you, for I think it might please you. Unhappily, I had no time to write it out, and have not even an outline of it. But I intend to work further upon this subject and make a book upon it one of these days.
If I speak of it to-day it is because in this course I have treated all the questions upon which you ask my opinion.
Let me answer them here after a somewhat aphoristic fashion.
I find it impossible to attribute the biological phenomena, which have been and still are going on upon the surface of our globe, to the simple action of physical forces.
I believe they are due, in their entirety, as well as individually, to the direct intervention of a creative power, acting freely and in an autonomic way. . . . I have tried to make this intentional plan in the organization of the animal kingdom evident, by showing that the differences between animals do not constitute a material chain, analogous to a series of physical phenomena, bound together by the same law, but present themselves rather as the phases of a thought, formulated according to a definite aim. I think we know enough of comparative anatomy to abandon forever the idea of
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the transformation of the organs of one type into those of another.
The metamorphoses of certain animals, and especially of insects, so often cited in support of this idea, prove, by the fixity with which they repeat themselves in innumerable species, exactly the contrary.
In the persistency of these metamorphoses, distinct for each species and known to repeat themselves annually in a hundred thousand species, and to have done so ever since the present order of things was established on the earth, have we not the most direct proof that the diversity of types is not due to external natural influences?
I have followed this idea in all the types of the animal kingdom.
I have also tried to show the direct intervention of a creative power in the geographical distribution of organized beings on the surface of the globe when the species are definitely circumscribed.
As evidence of the fixity of generic types and the existence of a higher and free causal power, I have made use of a method which appears to me new as a process of reasoning.
The series of reptiles, for instance, in the family of lizards, shows apodal forms, forms with rudimentary feet, then with a successively larger number of fingers until we reach, by seemingly insensible gradations,
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the genera
Anguis, Ophisaurus, and Pseudopus, the Chamosauria, Chirotes, Bipes, Sepo, Scincus, and at last the true lizards.
It would seem to any reasonable man that these types are the transformations of a single primitive type, so closely do the modifications approach each other; and yet I now reject any such supposition, and after having studied the facts most thoroughly, I find in them a direct proof of the creation of all these species.
It must not be forgotten that the genus
Anguis belongs to
Europe, the Ophisaurus to
North America, the Pseudopus to
Dalmatia and the
Caspian steppe, the Sepo to
Italy, etc. Now, I ask how portions of the earth so absolutely distinct could have combined to form a continuous zoological series, now so strikingly distributed, and whether the idea of this development could have started from any other source than a creative purpose manifested in space?
These same purposes, this same constancy in the employment of means toward a final end, may be read still more clearly in the study of the fossils of the different creations.
The species of all the creations are materially and genealogically as distinct from each other as those of the different points on the surface of the globe.
I have compared hundreds of species
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reputed identical in various successive deposits,—species which are always quoted in favor of a transition, however indirect, from one group of species to another,—and I have always found marked specific differences between them.
In a few weeks I will send you a paper which I have just printed on this subject, where it seems to me this view is very satisfactorily proved.
The idea of a procreation of new species by preceding ones is a gratuitous supposition opposed to all sound physiological notions.
And yet it is true that, taken as a whole, there is a gradation in the organized beings of successive geological formations, and that the end and aim of this development is the appearance of man. But this serial connection of all successive creatures is not material; taken singly these groups of species show no relation through intermediate forms genetically derived one from the other.
The connection between them becomes evident only when they are considered as a whole emanating from a creative power, the author of them all. To your special questions I may now very briefly reply.
Have fishes descended from a primitive type?
So far am I from thinking this possible, that I do not believe there is a single
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specimen of fossil or living fish, whether marine or fresh-water, that has not been created with reference to a special intention and a definite aim, even though we may be able to detect but a portion of these numerous relations and of the essential purpose.
Are the present fishes superior to the older ones?
As a general proposition, I would say,
no; it seems to me even that the fishes which preceded the appearance of reptiles in the plan of creation were higher in certain characters than those which succeeded them; and it is a strange fact that these ancient fishes have something analogous with reptiles, which had not then made their appearance.
One would say that they already existed in the creative thought, and that their coming, not far removed, was actually anticipated.
Can the fishes of the Old Red be considered the embryos of those of later epochs?
Of course they are the first types of the vertebrate series, including the most ancient of the Silurian system; but they each constitute an independent fauna, as numerous in the places where these earlier fishes are found, as the present fishes in any area of similar extent on our sea-shore to-day.
I now know one hundred and four species of fossil fish from
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the Old Red, belonging to forty-four genera, comprised under seven families, between several of which there is but little analogy as to organization.
It is therefore impossible to look upon them as coming from one primitive stock.
The primitive diversity of these types is quite as remarkable as that of those belonging to later epochs.
It is nevertheless true that, regarded as part of the general plan of creation, this fauna presents itself as an inferior type of the vertebrate series, connecting itself directly in the creative thought with the realization of later forms, the last of which (and this seems to me to have been the general end of creation) was to place man at the head of organized beings as the key-stone and term of the whole series, the final point in the premeditated intention of the primitive plan which has been carried out progressively in the course of time.
I would even say that I believe the creation of man has closed creation on this earth, and I draw this conclusion from the fact that the human genus is the first cosmopolite type in Nature.
One may even affirm that man is clearly announced in the phases of organic development of the animal kingdom as the final term of this series.
Lastly: Is there any reason to believe that
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the Ichthyosaurians are descendants of the Sauroid fishes which preceded the appearance of these reptiles?
Not the least.
I should consider any naturalist who would seriously present the question in this light as incapable of discussing it or judging it. He would place himself outside of the facts and would reason from a basis of his own creating. . .
In the ‘Revue Suisse’ of April, 1845, there is a notice of the course of lectures to which reference is made in the above letter.
A numerous audience assembled on the 26th of March for the opening of a course by Professor Agassiz on the “Plan of creation.”
It is with an ever new pleasure that our public come together to listen to this savant, still so young and already so celebrated.
Not content with pursuing in seclusion his laborious scientific investigations, he makes a habit of communicating, almost annually, to an audience less restricted than that of the Academy the general result of some of his researches.
All the qualities to which Mr. Agassiz has accustomed his listeners were found in the opening prelude; the fullness and freedom of expression which give to his lectures the character of a scientific causerie; the dignified
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ease of bearing, joined with the simplicity and candor of a savant who teaches neither by aphorisms nor oracles, but who frankly admits the public to the results of his researches; the power of generalization always based upon a patient study of facts, which he knows how to present with remarkable clearness in a language that all can understand.
We will not follow the professor in tracing the outlines of his course.
Suffice it to say that he intends to show in the general development of the animal kingdom the existence of a definite preconceived plan, successively carried out; in other words, the manifestation of a higher thought,—the thought of God.
This creative thought may be studied under three points of view: as shown in the relations which, spite of their manifold diversity, connect all the species now living on the surface of the globe; in their geographical distribution; and in the succession of beings from primitive epochs until the present condition of things.
The summer of 1845 was the last which
Agassiz passed at home.
It was broken by a short and hurried visit to the glacier of the Aar, respecting which no details have been preserved.
He did not then know that
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he was taking a final leave of his cabin among the rocks and ice. Affairs connected with the welfare of the institution in
Neuchatel, with which he had been so long connected, still detained him for a part of the winter, and he did not leave for
Paris until the first week in March, 1846.
His wife and daughters had already preceded him to
Germany, where he was to join them again on his way to
Paris, and where they were to pass the period of his absence, under the care of his brother-in-law,
Mr. Alexander Braun, then living at
Carlsruhe.
His son was to remain at school at
Neuchatel.
It was two o'clock at night when he left his home of so many years.
There had been a general sadness at the thought of his departure, and every testimony of affection and respect accompanied him. The students came in procession with torchlights to give him a parting serenade, and many of his friends and colleagues were also present to bid him farewell.
M. Louis Favre says in his Memoir, ‘Great was the emotion at
Neuchatel when the report was spread abroad that
Agassiz was about to leave for a long journey.
It is true he promised to come back, but the New World might shower upon him such marvels
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that his return could hardly be counted upon.
The young people, the students, regretted their beloved professor not only for his scientific attainments, but for his kindly disposition, the charm of his eloquence, the inspiration of his teaching; they regretted also the gay, animated, untiring companion of their excursions, who made them acquainted with nature, and knew so well how to encourage and interest them in their studies.’
Pausing at
Carlsruhe on his journey, he proceeded thence to
Paris, where he was welcomed with the greatest cordiality by scientific men. In recognition of his work on the ‘
Fossil Fishes’ the
Monthyon Prize of Physiology was awarded him by the Academy.
He felt this distinction the more because the bearing of such investigations upon experimental physiology had never before been pointed out, and it showed that he had succeeded in giving a new direction and a more comprehensive character to paleontological research.
He passed some months in
Paris, busily occupied with the publication of the ‘Systeme Glaciaire,’ his second work on the glacial phenomena.
The ‘Etudes sur les Glaciers’ had simply contained a resume of all the researches undertaken upon the Alpine
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fields of ice and the results obtained up to 1840, inclusive of the author's own work and his wider interpretation of the facts.
The ‘Systeme Glaciaire’ was, on the contrary, an account of a connected plan of investigation during a succession of years, upon a single glacier, with its geodetic and topographic features, its hydrography, its internal structure, its atmospheric conditions, its rate of annual and diurnal progress, and its relations to surrounding glaciers.
All the local phenomena, so far as they could be observed, were subjected to a strict scrutiny, and the results corrected by careful comparison, during five seasons.
As we have seen, and as
Agassiz himself says in his Preface, this band of workers had ‘lived in the intimacy of the glacier, striving to draw from it the secret of its formation and its annual advance.’
The work was accompanied by three maps and nine plates.
In such a volume of detail there is no room for picturesque description, and little is told of the wonderful scenes they witnessed by day and night, nothing of personal peril and adventure.
This task concluded, he went to
England, where he was to spend the few remaining days previous to his departure.
Among the
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last words of farewell which reached him just as he was leaving the Old World, little thinking then that he was to make a permanent home in
America, were these lines from
Humboldt, written at
Sans Souci:
Be happy in this new undertaking, and preserve for me the first place under the head of friendship in your heart.
When you return I shall be here no more, but the king and queen will receive you on this “ historic hill” with the affection which, for so many reasons, you merit. . . .
Your illegible but much attached friend,
So closed this period of
Agassiz's life.
The next was to open in new scenes, under wholly different conditions.
He sailed for
America in September, 1846.