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The anal fin commences beneath the insertion of the second dorsal, but in some instances beneath the third ray of that fin; and they end together at some distance from the tail. The latter fin, when expanded, is round and large. The pectorals are very large, and, in common with the other fins (the first dorsal especially), exhibits a crenated edge.

The inferior surfaces of the gill-plates are beautifully clear, showing the dark red gilt fringes through their substance.

I have kept these Gobies in a fresh-water aquarium for some weeks with minnows and sticklebacks. The latter, although they seldom molest the minnows, wage war against the Gobies-biting their fins and tails, so that the fish become ragged and discoloured. These fish are usually somewhat more than an inch in length; and the largest instances do not exceed two and a quarter inches. I should mention also that the pattern on the back is so distributed as to exhibit four light bands alternating with the darker portions.

In conclusion, I may say that, should the fish above described prove a known variety, this paper may still be of some service, considering the meagre details we at present possess with respect to the Gobies.

A. HART EVERETT,

Portswood Road, Southampton. To the Editor of THE STUDENT.

PROGRESS OF INVENTION.-FIRE PLACES.

To the Editor of the Student.

Sir,— Will you permit me to refer to p. 395 of The STUDENT for December, and to make a brief remark on the improvements there suggested for our fire places ? Nothing can be better than the grate there described ; and that it answers well, is proved by the fact, that Mr. William Bland, of Hartlip-place, near Sittingbourne, has used grates precisely similar for full forty years. He invented them when he built Hartlip-place, of which he was also the architect. The house, throughout, is a model for convenience and comfort. Mr. Bland, I may add, is the author of standard works on architecture, on boat-building, and of agriculture.

I am, Sir, yours respectfully,

C. ROACH SMITH. Temple-place, Strood by Rochester,

January 18th, 1869.

LITERARY NOTICES.

A SKETCH OF THE ORIGIN AND PROGRESS OF THE ART OF WOOD ENGRAVING, with a Chapter Explanatory of a Box of Materials used in the Process, to accompany the Book. By Thomas Gilks, author of “ The Art of Wood Engraving," “A Practical Handbook,” etc. (Myers and Co.)Mr. Gilks has long occupied a high place amongst our wood engravers, and has, we believe, on several occasions given lectures on the history of his art. He now comes before the public with an elegant little volume, which will, no doubt, lead them to demand the execution of the promise, in the introduction, to issue “a number of choice unique unpublished facsimiles" in an enlarged work.

Mr. Gilks traces wood engraving to the Babylonians, Egyptians, and Chinese. The former appear to have stamped their bricks with incised wooden blocks, and he gives a drawing of an Egyptian brick-stamp, made of wood, and brought to this country by Mr. Lane, who obtained it from a tomb in Thebes. Du Halde is cited to show how the Chinese engraved the pages of their books, first tracing their characters on thin paper, glueing it to a wood-block, and then cutting away the superfluous parts, and leaving the letters in relief. The use of wood stamps is then traced to the Greeks, and their employment noted throughout the middle ages; after which come descriptions of the playing cards of the Germans, which were printed from wood-blocks in the fifteenth century. “The earliest pictorial woodcut known,” we are told, was obtained from a convent near Augsburg, and bears the date of 1423. “This interesting specimen represents Saint Christopher, with the youthful Christ on his shoulder, paddling over the stream amongst the fishes. To the right of the picture is the hermit's cell, the hermit holding up a large lantern to light the saint over. On the left is a water-mill with the water running over the wheel, and from the back of the mill is to be imagined the miller carrying a load of flour to the distant cottage ; while in the foreground is seen a figure driving an ass towards the mill. At the bottom of the engraving is the date 1423, and a Latin version of these lines :

"Each day that thou the likeness of St. Christopher shall see,

That day no frightful form of death shall make an end of thee.'” Mr. Gilks proceeds to describe the block-books, and gives an account of the Psalter printed by Faust and Scheffer at Mentz in 1417:—“Only seven copies of this book are known to be in existence, and they were all printed on vellum, and in colours. The designs of the letters and engraving indicate an advancement in the art. This work is supposed to have been engraved by John Meydenback, Guttenberg's assistant; it may be seen in the library of the British Museum, Case 3, and even in our now advanced stage of colours printing, the registering of the colours will bear the closest inspection.” Passing rapidly over other early wood

engravers, a chapter is devoted to Albert Durer, whose portrait is given as engraved by himself; and in the succeeding chapter is a fine reduced facsimile of a chiaro-oscuro by the younger Goltius (1557). This, amongst numerous meritorious illustrations, is the gem of the book. The historical portion of the little volume concludes with an account of Bewick and other members of the English school, and the last chapter explains the mode of using the tools.

Ox MOLECULAR AND MICROSCOPIC SCIENCE. By Mary Somerville, Author of the "Mechanism of the Heavens," "Physical Geography," “Connection of the Physical Sciences," etc. 2 vols. (Murray)—We are all proud of Mary Somerville, and her writings occupy a foremost place amongst those which have contributed to the popularization of real science, in contradistinction to the twaddle and blunder so frequently put forth for general use. But, while fully recognizing her grasp of intellect, her fine apprehension of leading principles, and her exquisite power of elucidation, we cannot but feel some regret that she should have undertaken an extensive compilation of microscopical matters, under circumstances by no means favourable to the performance of such a task. At first sight, many will ask why molecular science should be associated with an account of the structure of infusoria, and of various minute organisms, or parts of organisms belonging to the vegetable world, or to the animal series below the vertebrata ; but a little reflection will show not only the justification, but the utility of such a plan. The microscope brings us into close contact with molecular physics and molecular chemistry, and a knowledge of these subjects is an essential prelude to the successful application of the instrument to the investigation of physiological problem.

In a portion of the first volume of the work before us, a great deal of valuable information is brought together concerning chemical substances and actions, the phenomena of heat, light, electricity, etc., and it is presented in so pleasant a form as to charm many into the paths of knowledge who would be scared away from them by more formal treatises or less skilful expositions. But we think the author mistaken, in a very positive adherence to the doctrine of atoms, as taught in the chemistry of the last generation, and which is now in process of abandonment by the most advanced and cautious thinkers. The doctrine that all bodies consist of atoms “excessively hard," indestructible, and “ever the same,” is founded upon gratuitous suppositions, not necessitated by facts, and not necessary to the explanation of any known group of phenomena ; and when we are told that the matter in onr terrestrial globe has never increased or diminished, we ask upon what ground such an assertion is made. Astronomy supplies proof that no important change in the weight of the earth can have occurred in long periods; but this is no proof of the proposition laid down. Since it has been shown that light, heat, etc., are modes of motion of matter,

we are led to assume the existence of matter throughout space, so far as we are acquainted with it; and who shall say, that while nebulous matter appears to be condensing into suns and planets, there is no counter-process, however slow, of dissipation of such bodies into the cosmic atmosphere.

In speaking of ozone, Mrs. Somerville refers to the experiments of Messrs. Tait and Andrews, illustrating its coroposition, and after this, she mentions, with approbation, Shönbein's theory of the two ozones, ozone and antozone, capable of neutralizing each other, and forming normal oxygen by their union. This theory does not seem to stand the test of facts, and we think, if Mrs. S. had read Professor Heaton's paper in the first volume of The STUDENT, she would have perceived its fallacy.

The natural history portions of Mrs, Somerville's work range from the simple alge to the more complex kinds, thence to fungi, ferns, endogens, the protozoa, hydrozoa, annulosa, echinodermata, crustacea, cirripedia, polyzoa, tunicata, and mollusca. In these chapters, a great amount of information is very agreeably conveyed, but errors have not been avoided, such as a repetition of Stein's acinetan theory, which he acknowledges to be wrong in his “Organismus der Infusionsthiere.” We should also object to placing the euglene in the animal series, and to treating the hexagonal appearances of diatom dots as a correct intimation of their form. We mention these as instances of a class of error from which the work is by no means free, and which, the author living away from this country, and without adequate access to books and authorities, could scarcely avoid. That the book will be extensively read, we hope, and have no doubt, as it will efficiently promote the taste for microscopical science; but it must not always be taken as a safe guide to the latest researches and opinions. It forms two elegant volumes, profusely illustrated, and it would be unfair to allow the reader to suppose that its defects were sufficient to counterbalance its numerous and characteristic merits.

DR. CARPENTER'S DREDGING REPORT.

In our last number we gave an account of some of the most interesting results of the Deep-sea Dredging Expedition, so successfully conducted by Dr. Carpenter. The full details of the various discoveries made will not be published for some time; but the “Proceedings of the Royal Society ” contain a “preliminary report" by Dr. Carpenter, from which, on account of the interest of the subject, and the large number of our readers who may not have access to the original document, we shall make more voluminous extracts than is our wont, selecting those parts in which the general conclusions arrived at are succinctly embodied.

"The results of our dredgings fully confirm the indications afforded

by the specimens of the bottom previously brought up by the soundings already noticed, in regard to the existence, on the sea-bottom of large areas of the North Atlantic, of a stratum of “calcareous mud," partly composed of living Globigerinæ, partly of the disintegrated materials of the shells of former generations, and partly of the “Coccoliths of Professor Huxley (loc. cit.) and the “Coccospheres ” of Dr. Wallich, with a greater or less admixture of other constituents. And they further indicate that the prevalence of this deposit is connected with a bottomtemperature of 45° and upwards, which, in latitudes above 56°, can scarcely be attributed to any other influence than that of the Gulf. stream.”

“Our researches have brought out with remarkable force the resemblance between this calcareous deposit and the great chalk-formation, which had been previously pointed out by Professor Bailey, Professor Huxley, and Dr. Wallich, but more particularly by Mr. Sorby, who identified the “Coccoliths” of Professor Huxley and the “Coccospheres" of Dr. Wallich with bodies observed in chalk.

“The existence of this deposit over a very large area was marked out by our dredgings at the extreme distance of 200 miles, and by several intermediate soundings; and the variations in its character corresponded closely with those which present themselves in different parts of the same stratum of chalk.

“But besides confirming the views already promulgated, as to the complete dependence of this calcareous deposit on the enormous development of low forms of organic life, our researches also show that the area over which this deposit is being formed is peopled by a variety of higher types of marine animals, many of which carry us back in a most remarkable manner to the cretaceous epoch. Thus, among Mollusca we have two Terebratulidæ of which one at least (Terebratulina caput-serpentis) may be certainly identified with a cretaceous species, while the second (Waldheimia cranium) may be fairly regarded as representing, if not lineally descended from, another of the types of that family so abundant in the chalk. Among Echinoderms we have the little Rhizocrinus, that carries us back to the Apiocrinite tribe which flourished in the colitic period, and was until lately supposed to have had its last representative in the Bourgetticrinus of the chalk, to which the Rhizocrinus presents many points of remarkable correspondence. Among Zoophytes, the Oculina we met with in a living state seems generically allied to a cretaceous type (O. explanata of Michelin). And the remarkable abundance of Sponges, which not improbably derive their nutriment from the protoplasmic substance that enters largely into the composition of the calcareous mud wherein they are imbedded, is a pre-eminently conspicuous feature of resemblance. We can scarcely doubt that a more systematic exmination of the remarkable formation at present in progress would place in a still stronger light the relationship of its fauna to that of the cretaceous period, since the specimens

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