Mode Of Arrangement Research Articles

Chromosome studies in Pisces

So far as the author is aware, the chromosomes of gobiid fishes have never been studied by any author. The present paper deals with the chromosomes in male germ cells of Tridentiger obscurus and Acanthogobius flavimanus belonging to the Family Gobiidae. No numerical and morphological differences of chromosomes were observed between these two species, as clearly seen by reference to the accompanying figures (Figs. 1-16). The diploid number of chromosomes counted in the spermatogonial division is 44, all being of telomitic type with gradual difference of length. The only visible difference lies between the smallest two pairs which are quite conspicuous on account of their remarkable minute size in Tridentiger obscurus.The haploid number, 22, is clearly demonstrated in the primary and secondary spermatocytes.In none of the cases described above, there was any evidence for the presence of the particular chromosomes, either in behaviour or in structure.Apparently the chromosome complex of the Gobiidae resembles those in some Pisces such as certain Cyprinidae, Cyprinodontidae, Gasterosteidae, Pholidae and Cobitidae, in many points, i.e. in their number, form and mode of arrangement.

New Etching Pattern of Quartz and Its Uses for the Determination of Electric Axes and the Detection of Crystalline Defects

A new etching pattern of quartz is formed, when a plate cut normal to the optic axis is subjected to the actions of hydrofluoric acid and electric field simultaneously. The general aspects of the pattern vary with the field intensity. In the case of weak field, the etching pattern consists of a number of regularly orientated small triangular figures which change their orientation from one twinned part to another. On the other hand, under the action of strong field, the triangular figures produced are generally smaller in size but by far greater in number than in the first case. The most striking features, exhibited in most of the etched surfaces under strong fields, are the appearance of groups of parallel long lines and bands as well as a kind of new etched zones which are similar in appearance but unlike in nature, the ordinary twinned zones. These groups of parallel lines and bands are exactly parallel to the electric axes of quartz; the presence of these lines and bands affords a very convenient way for the determination of the axes. There is reason to believe that the localities where the groups of parallel lines and bands as well as the new etched zones are found, are the seats of new crystalline defects arising from the so-called ‘primary’ crystal flaws. Some effects of the new crystalline defects on the oscillation characteristics of quartz oscillators are observed. The triangular etching figure, as revealed by a microscope, is composed of three sets of brushy parallel lines which make 120° with each other. The orientation of these sets of lines is a function of the applied field; those produced under weak field are approximately parallel to the three electric axes of quartz, with their outward ends directed to the positive extremities of the electric axes by compression, while those formed in strong field may deviate from the corresponding axes by as much as some ten degrees. Both the sense of deviation of the sets of lines with reference to the corresponding electric axes and the mode of arrangement of these brushy lines are found to be closely related with the sense of optical rotation of quartz. A general and accurate (to 1°) method for the determination of electric axes of quartz and their polarities, basing on the use of the orientations of the elementary etching figures, has been described.

39. The Comparative Anatomy of the Tongues of the Mammalia. – VI. Summary and Classification of the Tongues of the Primates.

39. The Comparative Anatomy of the Tongues of the Mammalia. – VI. Summary and Classification of the Tongues of the Primates.

On the effect of a longitudinal magnetic field on the internal viscosity of wires of nickel and iron, as shown by change of the rate of subsidence of torsional oscillations

We can obtain information as to the nature of the magnetisation of magnetisable bodies only by testing the various hypotheses with reference to effects which it seems likely should, under these hypotheses, be produced on the physical properties of the substance. Thus, for example, the internal friction of the different parts of a solid must depend upon the size and mode of arrangement of these parts, and any alteration in their dimensions or relative arrangement ought in general to produce some change in the amount of the internal friction.

Physiologische Pflanzenanatomie im Grundriss dargestellt

WHEN one recognises the immense importance of continually keeping before the student, the fact that from whatever standpoint the plant is viewed, physiological considerations must never be lost sight of, one cannot but welcome the appearance of Dr. Haberlandt's text-book on physiological plant anatomy, and one is disposed to do so with more than ordinary favour, recalling those chapters on physiological organography which appeared some three years ago in Prof. Sachs's “Vorlesungen.” The subject is one to which Dr. Haberlandt has specially devoted himself, the present volume being in fact the most recent of a series of detailed publications. On this account it is not surprising to find that much of the subject-matter is not new, and that of the twelve sections into which the book is divided five have already appeared in the article in Schenk's handbook entitled “Die physiologischen Leistungen der Pflanzengewebes.” Dr. Haberlandt's aim on the present occasion is to publish as complete an account as may be, of the present history of the subject, and the great point upon which he insists, is that the whole anatomical structure and the mode of arrangement of the various tissues composing the plant, are simply so many illustrations of the phenomenon of adaptation to physiological needs. Physiologische Pflanzenanatomie im Grundriss dargestellt. Von Dr. G. Haberlandt. (Leipzig: Wilhelm Engelmann, 1884.)

Fungi: their Nature, Influence, and Uses

THE names both of Dr. Cooke and Mr. Berkeley appear on the title-page of this work, but in the editor's preface it is stated that the whole of the manuscript was prepared by Dr. Cooke. There is very much that is interesting in this volume, but upon the whole the book is a disappointing one. The editor states that the work is intended for students, but we fear that the junior student will be repelled rather than attracted by the hosts of scientific names of genera and species which crowd many of the pages with italics. Then we cannot but condemn the mode of arrangement of the contents.

Recent Discovery of Pit-Dwellings

DURING the late summer, while engaged in excavating a Roman building at Finkley, near Andover, a deep trench, 100 feet in length, was found, dilating at the opposite ends into large subterranean pits, which, from the primitive character of the articles met with in them, such as flint and bone implements, spindle-whorls of chalk, and a rude form of pottery, appeared to belong to an earlier period than the Roman. One of the labourers engaged in the explorations became quite an expert in the recognition of these rude objects; and he having lately been employed in digging a yard at a new railway station, situated on a hill, about half a mile distant from St. Mary Bourne, immediately overlooking the Upper Test Valley, found the subsoil so abundant in calcined stones, broken pottery, and other evidences of early occupation, that he called my attention to the circumstance, which led to the discovery of a group of pit-dwellings or hut-circles; and it is likely, from their mode of arrangement, that they form a portion of an extensive settlement or vicus. Some knowledge of nine of these has been obtained, although, from their situation, two only have been completely investigated, and five others partially.

XXIV. On the anatomy of Victoria regia.―Part II

In a contribution to the Philosophical Transactions of this Society, published in 1852 (Part II. p. 289), I gave an account of the internal anatomy of the stem or rhizome of Victoria regia . I then stated that I regarded the arrangement of the vascular structures as essentially agreeing with that typical in Monocotyledons, and I directed attention to certain points of less importance, some of which appeared to strengthen the general argument in question, while others were opposed to it. Subsequently I have had an opportunity of studying the anatomy and development of the leaves, roots, and flowers of Victoria , and of observing some interesting facts which have not been clearly made out in any of the various memoirs which have appeared on this subject. I have also been led to a reconsideration of the subject of the anatomy of the stem by a criticism which appeared in the ‘Flora Indica’ (p. 236), the distinguished authors of which, in their advocacy of the opinion that the Order Nymphæaceæ is really Dicotyledonous, question the agreement which I have declared to exist between the structure of the stems of Victoria and of Monocotyledons. In the present paper, which may be regarded as a continuation and completion of the former, I shall first deal with the debated question of the structure of the rhizome, and afterwards give an account of the development of the appendicular organs, including the flower, and of the phenomena presented in the germination of the seed. For the abso­lute determination of the question whether a stem were organized on the Monocotyledonous or the Dicotyledonous type, it would be requisite first of all to define clearly what conditions we regard as typical in the two classes. This is no easy matter in the present state of our knowledge. The old terms Endogenous and Exogenous growth are founded on no corresponding contrast in the organization of the plants to which they refer. Exogenous growth is a reality, but endogenous growth is a figment of the imagination. The general distinctions between the stems of the two great classes of Angiospermous Flowering Plants depend upon a different mode of arrangement of the fibro-vascular bundles, and, usually, in addition to this, upon a different mode of arrangement of the elementary organs in the fibro-vascular bundles. These are the only essential differences; the formation of annual rings is by no means a constant phenomenon in perennial Dico­tyledons. It offers, however, a negative character for the Monocotyledons, since, from the construction and arrangement of their fibro-vascular bundles, they cannot produce annual (or periodical) rings of the same kind as those of the Dicotyledons. The layers formed in such exceptional instances as Yucca, Dracæna , and analogous stems are totally different from those of the layers of Dicotyledons, being formed of entirely new fibro-vascular cords quite independent of those of the inner substance of the stem, while the successive layers of the stems of Dicotyledons are ordinarily horizontal developments from the cambium layers of the pre-existing bundles.

XXV. On the anatomy and physiology of the Spongiadæ

The arrangement of the Spongiadæ by Lamarck, based entirely on external form, is wholly inadequate for the discrimination of species. The classification adopted by Drs. Fleming, Grant, and Johnston, dependent more especially on the chemical constituents of those bodies, is far too limited to be applied in generic characters. The author has, therefore, for this purpose rejected both systems, and has retained the latter one for forming primary divisions only, and he purposes founding the generic characters principally on the organic structure and mode of arrangement of the skeleton, in accordance with the practice so generally adopted by naturalists with regard to many of the higher classes of animals.

Observations on the Nature of Capillaries, and on the mode of arrangement of those in the Gills of Fishes

Observations on the Nature of Capillaries, and on the mode of arrangement of those in the Gills of Fishes