(1) The EOPALEOZOIC, characterized by almost universal seas over the Continental areas, by the display of Invertebrate marine life under nearly all its grander divisions, and by the first appearance of marine Vertebrates-all eminently thalassic features; and by the appearance of the earliest of terrestrial plants and Invertebrates.

(2) After the making in North America of the Taconic Mountain system and the attendant raising of land above the sea along the wide Atlantic border, the NEOPALEOZOIC, characterized by the increasing emergence of the land of eastern North America, and also by the further emergence of life, until, through the progressing developments, a great semicontinent existed, that of eastern North America covered with forests and populated by Amphibians and Reptiles, along with gigantic Insects and various inferior species.

The Devonian era is made to commence with the Oriskany period; and the Catskill period, hitherto the last, is dropped, the deposits being now regarded by workers in the field, as a sea-shore phase of the Upper Devonian. In the first edition of this work (and still earlier in 1855), the Subcarboniferous, Carboniferous and Permian periods were made to represent one age or era, and the age was named the Carboniferous; but in this new edition, since the double use of the name Carboniferous is objectionable, Renevier's term, Carbonic, first published by him as the name of the era in 1874, is substituted. The name Subcarboniferous is retained because it has priority, D. D. Owen having formally proposed it for the period in his final quarto report, of 1852, on the Geological survey of Wisconsin, Iowa and Minnesota.

The American Cretaceous period is divided into epochs based on the Cretaceous series of Texas and the Continental Interior, which in general is sufficiently fossiliferous to serve as the basis of time-divisions. Those of the Lower Cretaceous are named the Trinity, Fredericksburg and Washita epochs, from Prof. R. T. Hill's Texas section; and those of the Upper, the Dakota, Colorado, Montana and Laramie, from the Cretaceous of the Continental Interior, after the grouping of Eldridge. Moreover the Laramie is divided into the Lower Laramie, and the Denver group or Upper Laramie.

It is brought out in this connection that Mesozoic time, like Paleozoic, ended in North America in the making of a great coal-bearing formation, and as the coal period closed there followed mountain-making on a grand scale and world-wide disappearance of species; and that further, as, after the Paleozoic, the emergence from the water of the eastern half of North America took place, so, after the Mesozoic, there was the final emergence of the western half. The Post-cretaceous mountain system of the Rocky Mountains is called the Laramide, and it is described as extending from near the Arctic seas to Central America; and as having probably its counterpart in South America, along the line of the Andes,

Under the Quaternary, the three periods are, as before, the Glacial, Champlain and Recent, and the same grand continental or epeirogenic movements, first appealed to by the author in 1855, are still recognized as distinguishing them. The Glacial period is divided into three epochs (1) The Early Glacial, or that of the Advance of the ice to its maximum extension; (2) the Middle Glacial, or that of the First retreat; and (3) the Later Glacial, or that of the Final retreat.

Evidence is presented connected with the distribution of birds and other species, proving that during the Glacial period the Antarctic lands were emerged, and that the Antarctic continent, so made, spread northward until more or less closely connected with Australia, New Zealand, South America, Madagascar, and Southern Africa, so that it added to the efficiency of high latitude elevation in giving a glacial climate to the period. The work also states evidence for believing that the semiglaciated condition of South Africa, India and perhaps Australia, in the later Permian, was probably due to similar Antarctic conditions.

Through the Historical Geology, the history of an era is followed by a review of the geological and biological progress made during it, thereby illustrating the stages in Continental growth, and briefly the stages in the history of living species. In the closing chapter of the work, making the last of the series on the Progress in the Earth's life, the author sets forth in a more general way his views on evolution. Referring,-under the heading "Augmentation of variations by interbreeding fundamental in evolution" -to the augmentation of variations by selective breeding, and the strange diversity of results thus educed, he says: "it is perceived that the law of nature here exemplified is not like produces like, but like with an increment," and that "consequently the law of nature, as regards the kingdoms of life is not permanence but change, evolution." Two following paragraphs have the headings: "Natural selection not essential to evolution, variation being effectual without it" (that is the variation that goes forward under the slow and sure processes of free nature); "Natural selection a means of determining the successive floras and faunas of the world, a prominent cause of the geographical distribution of species." Moreover, a "tendency upward" in the Animal Kingdom is stated to be a necessary consequence, under favorable conditions, of the existence of a cephalic nervous mass or ganglion. The theory advocated is essentially the Lamarckian, Evolution by variation," not "Evolution by Natural selection."

The illustrations in the work have been increased in number by more than 400, making the total over 1575, and to them is owing in part the increased size of the volume. They include a bathymetric map of the Atlantic and Pacific oceans, another of the Arctic ocean, a temperature oceanic chart, a map of the Great Lakes; seven maps illustrating the supposed geographical condition of the North American Continent at different times in its history from the Archæan to the Quaternary, a map of the

Yellowstone Park, and others, besides very large additions to the figures of fossils.

This edition is issued thirty-two years after the first, twentyone after the second, and fifteen after the third. In the preparation of the third, the Historical Geology was only partly revised. 4. Manual of the Geology of India, chiefly compiled from the observations of the Geological Survey, by H. B. MEDLICOTT and W. T. BLANFORD.-Stratigraphical and Structural Geology. Second edition, revised and largely rewritten by R. D. OLDHAM, Superintendent Geological Survey of India. 543 pp. large 8vo. with maps, plates and illustrations in the text, Calcutta, 1893.— This new edition of the Manual of the Geology of India appears in a single volume. While the size of the Manual has been reduced by omission of less important parts and by condensations, the latest results of the survey of India have been incorporated, and a new colored geological map of the country is among its illustrations. The many peculiarities in the geological structure and orographic history of India make the study of the work of great importance to the geologists of other lands and especially to those of America. The addition of 20,000 feet to the height of the Himalayas after the Miocene period was a marvelous event in geological history; and the great fault-plane of a reversed (or up thrust) fault, "along the whole length of the Himalayas," against which the fresh water Siwalik beds of the Pliocene were deposited to a thickness of several thousand feet (now constituting the Subhimalayas) and other related facts, present orographic problems of profound interest. (On the colored map, a yellow band, extending along the north margin of the great alluvial plain of the Ganges and the south margin of the mountains indicates the position of the Siwalik Hills.) It adds to that interest that while these great changes were in progress in the mountain region, Peninsular India, the lower region, from 500 to over 1000 miles in width, lying between the Himalayas and the Indian Ocean, underwent little change. "The only prominent event which can be attributed to this period is the origin of the western Ghats."

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5. Recurrence of Ice-Ages.-PROF. T. McK. HUGHES, of Cambridge, England, in a paper read before the Cambridge Philosophical Society (Proc. Phil. Soc. 1893-94, 72. 98) entitled "Criticism of the Geological evidence for the recurrence of IceAges," makes the following statements in the course of his concluding remarks. "I have criticised the principal cases in which it has been contended that we have evidence of glacial action in ancient bowlder deposits, and have shown, by reference to actual specimens of the rocks in question, that, not only is the evidence of Paleozoic or Mesozoic glaciation in Britain inconclusive, but that the negative can be proved in all cases hitherto adduced.

Being thus warned against taking on trust evidence for glacial action in ancient times founded upon the form or the condition of the surface of the rock, I venture to throw doubts on the infer

ence that the faceted stones of Copitz near Pirna, are of glacial origin. I give the results of some of my own explorations among the ancient bowlder clays of Wetzikon, and other localities. I point out that the Cambrian-scratched stones of Norway are in regions that are still under the influence of glacial conditions in spite of the mild influences of the gulf stream. I then give a sketch of the distribution of bowlder-bearing beds in India, Australia and Africa, but have no evidence from personal observation to offer respecting them. I admit that the consensus of many competent observers renders it difficult to believe that these beds do not exhibit evidence of glacial origin.”

1. Mechanism of the movements of the stamens of Berberis.— CHAUVEAUD (Comptes rendus, July 2), suggests a new explanation of the curvature of the filament of Barberry, in response to touch or other irritation. He first calls attention to the inadequacy of one of the more widely accepted explanations, namely, that the movement is in consequence of the expulsion of water, showing by a simple experiment that water does not escape from a severed filament. He says that if a stamen be cut off at its base, and held in a dry place, it is possible, after it has recovered and straightened itself, to excite a new bending and after a second straightening to cause a second bending; all of which would not be likely to take place if there was at each movement a true expulsion of

water.

According to the author, the following is the anatomical structure of the filament of Berberis aristata. Besides the fibrovascular bundle there is a special tissue which occupies about twothirds of the transverse section and about two thirds of the length. This tissue is formed of narrow, elongated cells which are packed closely. This tissue possesses, especially towards the extremities of the cells, minute intercellular spaces. The transverse walls of its cells are thin, but the longitudinal walls, on the contrary, are thick, with thin places arranged longitudinally. This elastic tissue is covered by a layer which is practically continuous with the epidermis on the internal face and the sides of the filament and which may be called the motile tissue. But this motile layer differs from the rest of the epidermis in many ways. Its cells are rounded and thin-walled on their outer aspect, but notably thicker on the inner or deeper aspect. The contents differ widely from those of the other epidermal cells, being much more opaque. At the bottom of each cell of this layer, there is, when the organ is at rest, a peculiar thickening of the protoplasm into a sort of band. Under the influence of irritation, mechanical, physical, or chemical, the protoplasm reacts. This band suddenly stretches, curves into a bow, and while its ends touch and draw on the side walls, its convexity is pressed against the outer wall, resulting in a shortening and thickening of the cell. This causes a slight but

yet sufficient deformation, and produces a curvature of the filament toward the interior of the flower.

The contractile movements of these cells are very rapid. They demand for their manifestation perfect integrity of the tissue. When the tissue is acted on by Osmic acid, for fixation of the contents of the cells, it presents totally different appearances according to the phase of activity immediately preceding the employment of the reagent. In a state of rest, the protoplasm forms a dark band at the bottom of each motile cell. When the filament is cut longitudinally, these bands give the impresssion of a sort of ribbon, as long as the sensitive portion. But if the filament was in a state of tension when it was fixed, these bands are more or less detached and curved, and present an undulating appearance. These colored and fixed segments of protoplasm are very distinct from the rest of the cell contents, and can be readily photographed.

These intracellular changes had been previously noticed, but had been regarded as enlargements and diminutions of an intercellular substance readily susceptible to changes in the amount of water in the cell.

G. L. G.

2. The Harvard Botanical Museum.-The accuracy of the glass models of plants and the analytical details of their flowers, made by the botanical artists, Messrs. L. and R. Blaschka, has rendered it possible to exhibit all the morphological relations of more than two hundred North American genera. Above four hundred species from North, South, and Central America are now arranged in such order as to display affinities in a manner perfectly intelligible to every observant visitor. The minutest details are given on an enlarged scale, so that the position and character of the embryo in even the smallest seeds are fully and faithfully presented. All peculiarities of the essential organs and floral envelopes are displayed with absolute fidelity.

The success attending this venture has encouraged the installation of other specimens illustrating all the relations of plants to their surroundings, and to animals; in short, a full presentation of the Biological features of vegetation. In this biological section, the department of economic botany has, of course, its proper place and is to claim its proportion of space. The cooperation of the Director of the Museum of Comparative Zoology, at Cambridge, of the Director of the new Museums at Philadelphia, and of the Curator of the Peabody Museum, places in hand sufficient material for the realization of this comprehensive scheme, so far as the Phanerogams are concerned. In the installation of the Cryptogamia, Professors Farlow and Thaxter have given indispensable assistance, and some of their specimens are already in the cases. From present appearances about two years will elapse before all the relations of plants to their environment can be satisfactorily exhibited, but the systematic and economic departments are now open. The phytopaleontological exhibit will be in the same building, but on a lower floor.

G. L. G.