rocks in various parts of our island, which, although not sufficiently rich for gas-making, contain quite sufficient bituminous ingredients for agricultural purposes, particularly the enormous beds of shale which are at present left untouched in our coal-pits. But it is not in incidental suggestions like this, valuable as they may be, that this Report shows in the strongest light the important relations existing between the geological structure of a country and the farming operations carried on upon it. So high has the Board of Agriculture of Maine considered the advantage of such knowledge, that it has directed a special survey to be made of the whole State, "believing that such a survey, ably conducted, would greatly tend to develope and improve its agriculture;" and urging at the same time "that the utility and value of such explorations are no longer doubtful." This preliminary Geological Survey has been executed under the direction of Mr. Charles H. Hitchcock, of Amhurst, with Mr. Goodall, of Saco, as chemist, and Mr. Houghton as mineralogist. By them the seaboard from Saco to Calais was explored, and excursions made into the interior, and to the islands; next through the north of Washington County to Holton, and thence to Bangor. Subsequently up the Penobscot river, down the Alleguish and St. John river to Woodstock, through the iron and slate region of Piscataquis County, the country around Moosehest lake and the Penobscot river. By these explorations and the use of the valuable observations previously made by Dr. Jackson of Boston, a sufficient idea of the geological structure of the slate has been obtained for the construction of a general map, to serve as a basis for future systematic and more thorough explorations. It is not our intention to follow through the report of this, as far as it goes, excellent survey, but to gather rather from it such new or remarkable purely geological phenomena, as may be worthy of particular notice. One of these is a condition of the pebbles in a conglomerate bed on the northern border of Washington County, which is very remarkable. The inclination of the strata is some 65° easterly; the strike being N. 8° W. The layers are sometimes contorted, and numerous narrow perpendicular veins of quartz cut across their bedding. But the peculiarity of the conglomerate consists in the distortion and curvature of the pebbles it contains, the general appearance of which is illustrated in the accompanying sketch. They appear as if they had been drawn out,

curved, and pressed together by the forces to which they had been subjected. Mr. Hitchcock con

siders there is no doubt of these pebbles having been curved since the consolidation of the rock in which they are embedded; and even goes to the length of asserting, that such elongated pebbles have been changed into the siliceous laminæ of talcose and micaceous schists, while the cement has been converted into mica, the tale of talcose schists, and feldspar. To effect the change of form of the pebbles, according to Dr. Hitchcock's views, the substances of which they are composed require to have been brought into a soft or yielding state like moistened

clay, and then to have been contorted under the application of force or pressure; while to effect their still greater alteration into the lamina of schists, he looks to the further continued action of chemical changes amongst the heterogeneous sedimentary materials in selecting and combining the different mineral atoms in their proper proportions to form the new crystalline masses.

Letting alone this last topic, and confining ourselves to the phenomena of contortion only, if these pebbles were of clay, we could understand their being softened; but if they are of limestone, sandstone, slate, or flint, it is very hard to believe they ever were softened after they were once solidified. The phenomenon is, however, exceedingly remarkable, and not yet perhaps clearly explainable. It would seem to belong to the same class as the Nagel-Flue of Switzerland, so successfully investigated by Mr. Sorby, or as the nodular bands of limestone in the Wenlock Formation, to which attention has been drawn by M. La Touche and Mr. Salter. If anyone examines the ordinary condition of a conglomerate, or the nature of a sea-beach, the more or less rounded pebbles will be found simply piled one upon the other, very rarely are any elongated or flat, except when the pebbles are of slaty-rocks, and never bent unless they happen to be the fragments of naturally-curved strata. In no case are there any corresponding lines of contortion, such as shown in the woodcut, which represents a section of the Weston Conglomerate, in which the pebbles are drawn out and flattened, and compared by Dr. Hitchcock to spheres of clay pulled out into prolate-spheroids; and the pressure of an immense weight might, he thinks, be so continued as to elongate a pebble of clay into the resemblance of a lamina of quartz in gneiss. He makes intelligible the nature of the Weston Conglomerate by supposing that amongst many balls of clay some were plastic and some hard, and that these were then subjected to such a pressure as should pull out and flatten all the plastic ones, which would thus have their forms modified by the unyielding ones, the plastic pebbles fitting on the solid ones like a cap on the human head. “We find,” he says, among the distorted pebbles cases of this nature. Some pebbles have been more plastic than others, and the results are: indentations of the harder into the softer ones, curves around the hard ones, or the fitting of one into another like a ball into its socket, or the ends of the elongated pebbles may only fit upon each other to economize space"-as in the woodcut.

66

An example of the first stage of the distortion of pebbles is to be seen near Newport, R. I. The lower carboniferous conglomerate at Alms House, north of that city, is in a normal state, and consists of a mass of loosely-cemented cobble-stones, from an inch to six inches in diameter, all round or spheroidal; but two miles further, at Purgatory, there is another mass of conglomerate, nearly of the same age, having the pebbles much elongated in the direction of the strike, flattened, and often indented, "by being pressed one into the other;" they are sometimes a good deal bent, occasionally in two directions, the whole being cut across by parallel joints or fissures, varying in distance

from one or two inches to many feet. The cement is very meagre, and consists of talcose schist, containing crystals of magnetite: the pebbles, however, are firmly adherent. In small flexures of the strata, Dr. Hitchcock has observed the elongated pebbles bent at the same angles.

The part of the Philosophical Transactions of the Royal Society,'* containing Professor Owen's valuable and admirable Report on the extraordinary bird-remains from the lithographic limestone of Pappenheim-the Archaeopteryx macrorus-has been published during the past month, and the full particulars of the memorable description which excited such attention at Burlington House, in the November of last year, are now before the world. It appears to have received little alteration or emendation, as far as our memory will permit our judging, since the time of its first reading, when the completeness and lucidness of the account were features which prominently struck all hearers. The first evidence of bird-remains in the Solenhofen-beds was, as it is well known, the impression of a single feather, described and figured, with his characteristic minuteness and care, by Hermann von Mayer, in the Jahrbuch für Mineralogie,' under the title of Archaeopteryx lithographica, and although it is most probable that the class of birds was represented in the Solenhofen age by more than one family, Professor Owen has retained the generic appellation of Archæopteryx for the present specimen. As the reptilian pterodactyles of the lithographic stone differ in the length of their tails-some having extremely long ones, as the Ramphorhynchus longicaudus, and others scarcely any, as the Pterodactylus crassirostris, so we may expect to find similar differences in the strange birds which lived in those days; and just as the original appellation of Griphosaurus given to it by Wagner, under the idea of its being a feathered reptile, has been changed to Archæopteryx, it is not by any means certain that the generic term may not yet have to be again altered.

Professor Owen's paper commences with an account of the circumstances under which the specimen was found and those under which it was acquired for our national collection. The exposed bones in the specimen are then named, and one after another compared with those of recent birds of different species, and the corresponding bones of various fossil pterodactyles, a comparison requiring unusual care and accuracy on account of the previously supposed reptilian characters of the singular remains. By his examination and comparison Professor Owen has proved the general ornithic nature of the fossil-a conclusion which must be henceforth adopted; although there are some points which cannot be settled by the present relics, and which may hereafter, when fresh examples revive the subject, give rise to some important considerations. A magnificent lithograph of natural size is given of the principal slab and its contents, even to its ripples and surfacemarkings, by Mr. Dinkel, who has as conscientiously done his duty in

* Philosophical Transactions of the Royal Society of London,' vol. cliii. part 1, 1863.

as faithful a representation as it is in an artist's power to attain. But neither Mr. Dinkel nor any other artist can free himself from a bias of ideas. The hand will follow the mind, and given the notion of a fish's head, the pencil will involuntarily portray the resemblance in figuring the object to which the resemblance is assigned. When Professor Owen first described the Pappenheim specimen, he made no mention of what has since been described by Mr. Mackie as the brain or cast of the cerebral cavity of the skull, nor of certain osseous relics which in the present publication are referred to as a "premaxillary bone, and its impression resembling that of a fossil fish." And yet these objects are perhaps among, if not actually, the most important of all the fossilized remains. The nodule representing the brain, it is admitted by the Professor, may be, as suggested by Mr. Evans, "part of the cranium with the cast of the brain of the Archæopteryx;" but of the so-called fish-head he makes no other remark than the quotation above, "resembling that of a fossil fish." Nor do we blame his retiEvery word Professor Owen says carries weight, and the lastmentioned object is certainly in so obscure a state that no one, without further illustrative fossils, could by any possibility determine what it is. It would be discordant with all our present knowledge to find a bird's beak containing teeth in sockets, yet that would not be more extraordinary nor more out of all comparisons with living things than a long tail such as the Archeopteryx undoubtedly possesses. such a toothed bill may be possible. After many days' careful study and comparison we could not convince ourselves that this object was a fish's jaw, nor could we find evidence enough to assert that it was a bird's beak with teeth; but it certainly has, as it lies in the slab, as much likeness to a beak as to a premaxillary, and as there is not a fish-scale nor a fish-bone in the whole slab, nor in its counterpart, nor a speck nor portion of a fish in either, it is as possible for this object to belong to the Archæopteryx as to any other creature.

cence.

Yet

The general ornithic nature of the fossil is, as we have already said, indisputable, but not so positive do we think can anyone be as to its exceptional characters. If the Archeopteryx had in its long vertebrate tail, one character so exceptional as not to be matched by any existing or any other fossil bird, it may have had other characters as exceptional; and although we should say that no bird that preened its feathers would have teeth, yet the beak of a bird is but a modified mammalian jaw, just as the whole structure of birds is a modification of the mammalian type; so it is not without the bounds of possibility that a bird's jaw may be in such a state of development as to retain some traces of teeth. Nor can we be certain, it seems to us, that there are no reptilian affinities, or, at least, resemblances in the structure of the wings. Had the manus of Archæopteryx been adapted for the support of a membranous wing, the extent to which the skeleton is preserved, and the ordinary condition of the fossil Pterosauria in the lithographic stone, render it almost certain, as Professor Owen properly observes, that some of these most characteristic long slender bones of the pterosaurian wing-fingers would have been visible

if such had existed in the present specimen; and besides this negative evidence, the positive proof of the bird-like proportions of the pinion, and the existence of quill-feathers, sufficiently evince the true classaffinity of the Archeopteryx. We are, however, in ignorance as to the manner in which those singular wing-hooks were attached to the main bones of the wing, and of all the comparisons which Professor Owen has made with the spur-winged birds, such as the Merula dactyloptera, Anser gambensis, Parra jacana, Palamedea cornuta, and Megapodius, there are none, we believe, which give us a single illustration of the same character of organization as is exhibited by the claw-hooks in the Archæopteryx. Indeed, Professor Owen admits that in this respect, it differs from every known bird in having "two free unguiculate digits," i. e. the wing-hooks, "in the hand," and that "these digits in the slenderness of the penultimate phalanx do resemble the unguiculate digits in the hand of the Pterodactyle." But it is true, as Professor Owen continues, that "the claw has not the characteristic depth or breadth of that of the Pterodactyle; and there is no trace of the much lengthened metacarpal and phalangial bones of the fifth digit, or peculiar wing-finger of the flying reptile." We doubt, however, if the wing-claws of the Archeopteryx are comparable with the spurs of the jacana, or of the screamer; and we are not aware that the skeletons of either are obtainable in this country for comparison.

These are questions, however, which it is judicious of the Professor to avoid until there is sufficient evidence collected to warrant, if not a decisive, at least a reliable opinion. It is quite a different thing for us to point them out, that the importance of obtaining further illustrative specimens may be borne in mind.

VI. MICROSCOPICAL SCIENCE.

As the advance of all physical science depends in a great measure on the degree of perfection of the instruments with which it is studied, we propose devoting this, our first article on the progress of Microscopical research, to a brief exposition of the improvements that have been recently made in the construction of the instrument. Our next article, on the other hand, shall be devoted to a review of the modern standard works on the Microscope, and its mode of application; and then having, as it were, set our house in order, we shall be prepared in our subsequent Numbers to enter directly on the true object of our work, namely, to keep our readers au courant with the progress of microscopical inquiry.

Fortunately for us, we do not at the present day require to say anything in support of the claims of the microscope to public attention. Scientific men have unanimously decided in its favour, and although, among the general public, there are still individuals to be encountered who regard its teachings with distrust, their number is

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