« AnteriorContinuar »
ligence of these Bohemians, many of success, specimens of minute size, them coming from the most humble which enabled M. Barrande to trace class. Some of them, in ten or twelve their growth and mode of development, years' experience, acquired a remarkable and to complete the natural history of skill and facility in searching for fossils. the species. They were habituated to collect and re- In thus tracing the changes of form unite the smallest fragments of speci- which some trilobites underwent during mens broken in opening the rock, aided their growth, M. Barrande has added themselves by the lens in detecting the entirely new facts to our knowledge of obscure traces of the minutest embryos, these old crustaceans. He has noticed and recognized at once the novelty of one species (Sao hirsuta), when no any unknown form which they might larger than a pin's head, consisting, in find. A kind of nomenclature in the that stage, of a head plate and a seg. Bohemian tongue formed among them- ment or two of body; and followed its selves, served to distinguish the species development to its full size of an inch and strata. During many years we in length with nineteen segments. The never ceased to keep among these work- different forms of this trilobite had premen, and constantly to traverse our field viously so far misled M. Barrande, that to direct the excavations and to collect he had formed four different species of their products; and since the cares of this one; and another naturalist, M. publication confined us at Prague, some Corda, had actually made of its varying one has come every week to bring us appearances no less than eighteen spethe collections made, and to receive our cies. referred to ten different genera! instructions."
But our author, not satisfied with It is to this perseverance in explora- finding these trilobites of such minute tion even more than to the abundance of size, believes that he has even discoverfossils in Bohemia, that M. Barrande ed their petrified eggs, in some tiny attributes the extent and richness of black spheroids found in the same his collections. Could such a system layers which contain their disjointed rebe carried out in our own region, no mains! We may hesitate at giving our doubt the fullness and variety of our faith to this-yet it may be as genuine American Palæontology would be much a discovery as many others which, increased beyond the results of the questioned or rejected at their first limited and uncertain means hitherto announcement, have afterwards been employed. M. Barrande gives an ex- fully established. ample, showing how much time and The labor of publishing the result of pains have been necessary to obtain M. Barrande's researches thus far, has specimens for the complete illustration occupied six years. The plates are not even of a common form.
ordinary lithographs, but engravings on The remains of one trilobite (Dal- stone, sharp and distinct in every line, manites socialis) are found scattered as if on steel, and remarkable for the abundantly through certain strata, but care and minuteness of their execution, usually in fragments, heads, joints, and from the large paradoxides and asaphus tails separated and scattered asunder. which fill the quarto page, down to the It was only after years of search that tiny forms whose structure is shown certain layers were found to contain only under the magnifier. entire individuals; but they were too Ás new and better specimens were much defaced to serve as good speci- often discovered after the first drawing mens. Later, a locality was discovered of the species had been engraved, the in which they were complete, and in author has not hesitated to efface and good preservation. Hitherto, however, reëngrave many figures, and even a they were found only in an extended considerable number of entire plates, in form, but in continuing some excava
order that the work should possess all tions, they were found coiled up or con- possible completeness and accuracy: tracted, proving their possession of this The letter-press has also been revised faculty, before not established. Eight and modified, in order to embrace, as years had passed, and though multi- far as possible, every discovery up to tudes of adult specimens had been the last moment; so that, besides less found, it was not until 1850 that a new extensive alterations, 250 pages have explorer detected in slaty strata, pre- been entirely re-printed. No care has viously examined by others without been spared to make the work a reliable authority, and it lies before us a monu- fossils of this family—some of which ment of patience, industry, and scien- seem to have enjoyed a comparatively tific zeal.
brief existence, being found only in a The entire number of trilobites de- few contiguous layers, others extending scribed in it is about 250, being, proba- through a long succession of strata. bly, four times as many as are yet One species, the remains of which are known in the equivalent rocks of New found at intervals through a series of York. The future volumes will describe rocks not less than 6,000 feet in depth, about 850 species of other fossils, shells, must have endured on earth during an corals, encrinites, etc., etc., as M. Bar- immense lapse of time. rande has collected from all the Si- Not only are they limited in their lurian strata of Bohemia the relics of perpendicular range through the strata, over 1,100 different species of once
but in their horizontal extension. Some living forms. This aggregate will not appear to have been endowed with har. very greatly exceed the number obtain- dihood and powers of locomotion which ed by Professor Hall, from the Silurian enabled them to spread over thousands rocks of New York, for though our of miles; others, stationary in their crustaceans and some other organic re- habits, or able to exist only in particumains are less abundant, our corals and larly favorable localities, have left encrinites are more numerous and varied their remains within but narrow limits. than those of Bohemia.
Some species of bronteus are found M. Barrande considers that he has only in a single locality a mile or two remains proving the existence of only in extent; while the Calymene Blumena single species of fish at the top of the bachii is known in Bohemia, in England, Silurian system. The case is similar in and in America, from the Hudson River England and in this country, for though to Cincinnati. the British geological surveyors thought
Following the development of this they had found fish-bones in the lower interesting tribe, we find them at their Silurian rocks of Wales, and Mr. Hall, at greatest abundance about the middle of one time, supposed certain fossils of the the Silurian system; thence they graduNiagara group to be of the same charac- ally diminish, few being found in the ter, these relics are now admitted to be Devonian strata, and the last two or fragments of crustaceans. The Silurian three species becoming extinct in the system, therefore, appears to be the carboniferous system. Since then, they record of a period when no higher form have been unknown. of life than that of the trilobite existed, A new feature in Palæontology, so that, apart from the peculiar form which we must not pass unnoticed, and nature of these fossils, they have though it is not easy to state it cleara preeminent interest as having been, in ly and briefly, is introduced by M. Hugh Miller's phrase, “ the master-ex- Barrande in his theory of “colonies." istences” of the epoch when they lived. He finds, among the lower Silurian
The different genera of trilobites mica-slates, insulated masses of rock of characterize, with much regularity, the an entirely different character, but of successive portions of the Silurian sys- the same mineral composition and fossils tem. Some forms are peculiar to the with upper Silurian strata. From the lower strata, and being almost, or quite, latter they are separated by 3,600 feet unknown in New York, M. Barrande of over-lying mica-slate rock, in all its suggests that they belong to a period mineral and fossil characters like that prior to that at which our earliest strata which lies below them. They thus apwere formed; the second group of Bo- pear to be calcareous upper Silurian hemian trilobites corresponding with our
strata and fossils found far below their first, found in the Chazy and Trenton regular position; or, local formations limestones. If so, the Silurian chapter, anticipatory of the general prevalence. as found in Bohemia, has a few pages of similar strata which was afterwards of earlier history than ours. The gene- to occur. ra characterizing this group disappear, M. Barrande believes that these inand, with one exception, are not known terpolated strata were formed as it were in any higher position, but other forms parenthetically, during a temporary appear to have been created to replace suspension in the deposit of the micathem. Every portion of the pile of slate, and that the change was caused strata is characterized by its peculiar by a change or reversal of marine cur
rents. These, coming temporarily from sociated with eruptive masses of trap a direction opposite to that whence the in a disturbed basin, all impel us, in sediment of the mica-slate was derived, spite of M. Barrande's opinion, to susmight have arrested the deposit of the pect that these colonies may be only latter, and brought instead, from another detached fragments or outliers of the quarter, a calcareous deposit and a upper Silurian rocks, separated from different group of organic forms. Then, their original associations, and appathe return of the currents to their rently mingled with older strata by former direction might have restored faults, uplifts, denudation, or like causes. the slaty sediment and its appropriate No such phenomena as M. Barrande living tenants, until one more change describes are to be found here, where caused the calcareous deposit and its the strata are undisturbed and free peculiar fauna to prevail permanently from distortion or confusion. The or through a large part of the upper change from one rock to another is perSilurian period. Comparing this pro- manent, and entire masses of strata cess to the temporary invasion by a with complete groups of fossils never foreign population of a region in which alternate. Some old fossils, indeed, reit was eventually to prevail, M. Barrande appear in higher positions, and the gives to these interpolated strata with recurrence of strata of similar compotheir fossils the name of "colonies." sition is accompanied by the recurrence
The facts stated seem to form an of very similar groups of fossils. But exception to previous geological obser- there is no general identity between vations, and to shake our confidence the relics of two separate formations; in fossils as an accurate test of the on the contrary, the great proportion comparative antiquity of strata. If we are perfectly distinct. admit that forms which have been con- The question thus raised is an importsidered characteristic of different epochs ant one, and its final decision will be were existing at one time in adjoining awaited with much interest. We can seas, and that a mere change of cur- but think, that while our geologists will rents could cause distinct lower and be much aided in the study of Silurian upper Silurian deposits and fossils to fossils by European researches, still alternate, it would much confuse our doubts and difficulties, as to the order investigations. It seems almost impos- and succession of the older strata and sible that a change so produced could their organic remains, are to be decided be so total as that described by M. Bar- by the explorers of the broad and unrande. Some of the previously-existing disturbed geological field of the northspecies would, we should expect, con- ern United States. tinue to inhabit the same spot, even The union of effort, and the mutual though the sediment were changed; assistance rendered by students of naand some of the new settlers or colo- ture of different nations, in remote nists introduced by the change of cur- regions, is a pleasant thing to contemrents would remain as permanent resi- plate, and this union is yet to lead dents after the causes which brought to great results in the comparatively them ceased. The living forms of the clear and certain knowledge of many two adjoining regions would become subjects as yet but dimly comprehended. mingled, and it seems impossible that We must wish all success to these eartheir entire extirpation could occur, so nest explorers, and await with hope and as to form such entirely distinct alter- patience the time expected by M. Barnate groups of fossils.
rande, when, to use his own words, The precise identity of the fossils of “ some future man of genius, combithe “colonies" with those of the upper ning and generalizing from the great Silurian; the precise similarity of these mass of facts which the present age strata in mineral character, even to seems destined to collect, shall diffuse their nodules and sparry veins; the on the science of the earth all the light fact, if we correctly understand it, that which Newton, furnished with the these “colonial" masses have been observations of previous ages, was found only locally, and not traced as enabled to cast on the science of the extensive strata ; and that they are as- heavens."
the Valley of the Vire
On the stone
These words alone, “Oliver Basselin lived here."
Far above it, on the steep,
Ruined stands the old Château;
Its vacant eyes
Stare at the skies,
Once a convent, old and brown,
Looked, but ah! it looks no more From the neighboring hillside down On the rushing and the roar
Of the stream
Whose sunny gleam Cheers the little Norman town.
In that darksome mill of stone
To the water's dash and din, Careless, humble and unknown, Sang the poet Basselin
Songs that fill
That ancient mill With a splendor of its own.
Never feeling of unrest
Broke the pleasant dream he dreamed, Only made to be his nest, All the lovely valley seemed;
Of soaring higher
True, his songs were not divine;
Were not songs of that high art, Which, as winds do in the pine, Find an answer in each heart;
But the mirth
Of this green earth Laughed and reveled in his line.
From the ale-house and the inn,
Opening on the narrow street, Came the loud, convivial din, Singing and applause of feet,
The laughing lays
That in those days Sang the poet Bassolin.
In the castle, cased in steel,
Knights, who fought at Agincourt, Watched and waited, spur on heel; But the poet sang for sport
Songs that rang
In the convent, clad in gray,
Sat the monks in lonely cells, Paced the cloisters, knelt to pray, And the poet heard their bells,
But his rhymes
Found other chimes, Nearer to the earth than they.
Gone are all the barons bold,
Gone are all the knights and squires, Gone the abbot stern and cold, And the brotherhood of friars;
Not a name
Remains to fame,
But the poet's memory here
Of the landscape makes a part; Like the river, swift and clear, Flows his song through many a heart;
That ancient mill