bluuebunny/crossref_metadata_2025 huggingface dataset:
Cell density affects spreading and clustering, but not attachment, of human keratinocytes in serum-free medium
Authors: Malcovati Massimo , Tenchini Maria Luisa
Published: April 2021

Attachment, spreading and clustering of second-passage human keratinocytes in serum-free medium have been evaluated within 24 h after plating, as a function of the density of the inoculum and of time, in two different strains.

The results show that attachment is unaffected by cell density and differs significantly from strain to strain.

Cell density affects the distribution of attached keratinocytes among three morphologically distinct classes: unspread, spread and clustered cells. The percentage of unspread keratinocytes shows a linear decrease at increasing cell density, and that of spread keratinocytes an increase, resulting from statistically significant increases in the percentages of both single and clustered cells. Spreading on uncoated surfaces appears therefore as an inducible phenomenon. The use of media conditioned by keratinocytes, fibroblasts and HeLa cells shows that keratinocytes specifically secrete a diffusible ‘spreading factor’. We term this phenomenon ‘autocrine induced spreading’. Preliminary physicochemical characterization suggests that a protein could be responsible for the spreading activity of conditioned media. The ‘spreading factor’ seems to act directly on the cells, and not through a modification of the plastic surface of the dishes, since most (>70%) of the spreading activity can be recovered in the conditioned media used in pre-coating experiments.

The percentages of clusters follow ‘saturation’ kinetics at increasing cell density, while the percentage of clustered cells increases linearly with the density of inoculum.

Time-course experiments show that the rate of spreading is cell density- and strain-independent. The percentages of clusters and of total clustered cells are time-independent, suggesting that cluster formation takes place in suspension.

These data indicate the existence of a complex functional heterogeneity of cultured human keratinocytes.
Interactions between mesoderm cells and the extracellular matrix following gastrulation in the chick embryo
Authors: Brown A. J. , Sanders E. J.
Published: April 2021

In the gastrulating chick embryo, the mesoderm cells arise from the epiblast layer by ingression through the linear accumulation of cells called the primitive streak. The mesoderm cells emerge from the streak with a fibroblastic morphology and proceed to move away from the mid-line of the embryo using, as a substratum, the basement membrane of the overlying epiblast and the extracellular matrix. We have investigated the roles of fibronectin and laminin as putative substrata for mesoderm cells using complementary in vivo and in vitro methods. We have microinjected agents into the tissue space adjacent to the primitive streak of living embryos and, after further incubation, we have examined the embryos for perturbation of the mesoderm tissue. These agents were: cell-binding regions from fibronectin (RGDS) and laminin (YIGSR), antibodies to these glycoproteins, and a Fab’ fragment of the antibody to fibronectin. We find that RGDS, antibody to fibronectin, and the Fab’ fragment cause a decrease in the number of mesoderm cells spread on the basement membrane, and a perturbation of cell shape suggesting locomotory impairment. No such influence was seen with YIGSR or antibodies to laminin.

These results were extended using in vitro methods in which mesoderm cells were cultured in fibronec tin-free medium on fibronectin or laminin in the presence of various agents. These agents were: RGDS; YIGSR; antibodies to fibronectin, fibronectin receptor, laminin and vitronectin; and a Fab’ fragment of the fibronectin antiserum. We find that cell attachment and spreading on fibronectin is impaired by RGDS, antiserum to fibronectin, the Fab’ fragment of fibronectin antiserum, and antiserum to fibronectin receptor. The results suggest that although the RGDS site in fibronectin is important, it is probably not the only fibronectin cell-binding site involved in mediating the bevaviour of the mesoderm cells. Cells growing on laminin were perturbed by YIGSR, RGDS and antibodies to laminin, suggesting that mesoderm cells are able to recognise at least two sites in the laminin molecule. We conclude that the in vivo dependence of mesoderm cells on fibronectin is confirmed, but that although these cells have the ability to recognise sites in laminin as mediators of attachment and spreading, the in vivo role of this molecule in mesoderm morphogenesis is not yet certain.
Enhanced assembly of basement membrane matrix by endodermal cells in response to fibronectin substrata
Authors: Austria Martin R. , Couchman John R.
Published: April 2021

Basement membranes are complex extracellular matrices contributing to the regulation of growth, migration and differentiation of many cell types. However, little is known about the mechanisms regulating the deposition and assembly of basement membrane from its constituents. We have investigated the role of extracellular matrix molecules in the control of basement membrane matrix assembly by cultured endodermal (PFHR-9) cells. In the presence of fibronectin-depleted serum, substrata of fibronectin or laminin induced an increase in deposition of laminin, type IV collagen and proteoglycans by PFHR-9 cells, in comparison to cells adherent to type I collagen-coated, vitronectin-coated or uncoated substrata.

Direct effects of fibronectin or laminin on the degree of cell spreading or rate of proliferation were not responsible for enhanced matrix deposition. The effect did not result from a redirection of basement membrane components to the matrix, since there was no decrease in matrix constituents released to the culture supernatants. Furthermore, the synthesis and release of other molecules that are not basement membrane constituents was unaltered in response to different extracellular matrix substrata. Experiments with fibronectin fragments showed that a 105×10;lMr ‘cell’-binding domain (containing the cell attachment sequence Arg-Gly-Asp-Ser) was an important contributor to enhanced matrix deposition, while the N-terminal 29×103Mr heparin-binding domain also contributed to the effect, particularly with respect to heparan sulfate proteoglycan deposition. It seems that fibronectin has a dual role of action in promoting basement membrane matrix assembly, through direct cell surface interactions, and through the binding of fibronectin to other matrix components that may nucleate or stabilize the matrix assembly.
Intranuclear distribution of Epstein-Barr virus-encoded nuclear antigens EBNA-1, -2, -3 and -5
Authors: Jiang Wei-Qin , Wendel-Hansen Vidar , Lundkvist Åke , Ringertz Nils , Klein George , Rosén Anders
Published: April 2021

Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) express at least seven virally encoded proteins. Their functional role, and their relationships to each other and to normal nuclear constituents are virtually unknown. As the first step towards a topographical study, the intranuclear distribution of EBV-encoded nuclear antigens EBNA-1, -2, -3 and -5 (abbreviated El, E2 etc.) was examined in EBV-transformed LCLs by immunofluorescence and digital image analysis of fluorescence patterns. E1-E3 showed a finely granular distribution. The E2 patterns were virtually identical when comparing indirect staining using an E2-specific mouse monoclonal antibody with anticomplement immunofluorescence using a human antibody, rendered monospecific to E2 by absorption. The E1/E2 patterns showed 32% overlap and the E2/E3 10% overlap in the high overlap category (66.7-100%), while the E2/E2 comparison with two reagents showed 61 % overlap in this category. This suggests that E2 and E3 largely appear in different nuclear structures, whereas El appears to be randomly distributed with regard to E2. The E5 pattern was radically different from that of El, E2 and E3. The anti-E5 mouse monoclonal antibody detected 4-10 huge, globular, sharply circumscribed dots, located in dispersed chromatin areas, while the distribution of El, E2 and E3 showed no obvious relationship to chromatin distribution. The methods described here allow a more refined topographical analysis of the EBNA protein family, mostly in relation to each other, in relation to other nuclear proteins, and with respect to specialized functional domains in interphase chromatin. The topology of the EBNA proteins relative to other nuclear components may provide important clues about the role of growth transformation-associated proteins in cellular immortalization and viral latency.
Further observations on nucleolar tails in amphibian oocytes
Authors: León Pedro , Kezer James , Schabtach Eric
Published: April 2021

Large oocytes from some amphibian species possess beaded or unbeaded intranuclear tails that penetrate the extrachromosomal nucleoli through a distinct pit in their surface and attach to the central core component Here we show, using light and electron microscopy, that tails anchor nucleoli to the nuclear envelope through intricate attachment structures. These structures are composed of interconnected spherical masses containing highly convoluted tubules and associated extratubular proteins, directly in contact with the inner nuclear membrane. Fibers emerging from the nuclear pores seemingly hold the attachment complex in place. Beads on the nucleolar tails are formed by the accumulation of proteins on the outer surface of smooth tubules. The function of these intranuclear tubules is unknown.
Comparative behavior of lysosomes and the pre-lysosome compartment (PLC) in in vivo cell fusion experiments
Authors: Deng Yuping , Griffiths Gareth , Storrie Brian
Published: April 2021

Interspecies cell fusion was used to compare protein intermixing within the mannose 6-phosphate receptor (MPR)-enriched pre-lysosome compartment (PLC) and within the MPR-negative lysosomal compartment. Both compartments were positive for lysosomal glycoprotein (Igp) membrane markers but were morphologically distinct In most experiments, rat-mouse cell syncytia were formed by u.v.-inactivated Sindbis virus-mediated fusion. By immunogold electron microscopy of syncytia, extensive intermixing of species-specific lysosomal membrane proteins was observed in both lysosomes and PLC. At 3 h post cell fusion, multiple-label immunogold studies showed that 82% of the lysosome-like structures positive for the rat lysosomal membrane protein LIMP-I were also positive for the mouse lysosomal membrane protein mLAMP-1. By immunofluorescence, LIMP-I and mLAMP-1 co-localized with a t| of 30 min after cell fusion; although the Igp-positive organelle populations had evidently interchanged their proteins, the lysosomal structures remained small, punctate bodies distributed throughout the syncytoplasm as observed in single cells. In contrast, the initially separate units of the PLC congregated with a t| of 1 h to form large, pre-lysosome complexes associated with individual nuclear clusters. At the electron-microscope level, gold markers endocytized by the rat and mouse parent cells in a 1h uptake followed by a 16-20 h chase co-localized in these extended PLC complexes, as did the membrane markers mLAMP-1 and LIMP-I. The density of labeling for rat MPR in the extended PLCs was markedly decreased, consistent with membrane fusions and dilution of the antigen upon congregation of the PLC compartments from the donor cells. The extended PLC complex behaved as a late endocytic compartment, as shown by co-localization of the MPR and rhodamine-dextran following a 10 min dextran uptake and a 50 min chase. These differences in behavior between lysosomes and the PLC in rat-mouse cell syncytia suggest that the pathway(s) of protein intermixing with respect to the two organelles may be different.
Rapid epithelialisation of fetal wounds is associated with the early deposition of tenascin
Authors: Whitby David J. , Longaker Michael T. , Harrison Michael R. , Adzick N. Scott , Ferguson Mark W. J.
Published: April 2021

Wound healing is a complex process involving the interaction of many cell types with the extracellular matrix (ECM). Fetal skin wound healing differs from that in the adult in that it occurs rapidly and without scar formation. The mechanisms underlying these differing processes may be related to the fetal environment, the stage of differentiation of the fetal cells or the ECM deposited in the wound. The spatial and temporal distribution of two components of the ECM, fibronectin and tenascin, were studied by immunostaining of cryosections from trunk wounds of fetal and adult sheep.

Epithelialisation was complete earlier in the fetal wound than in the adult. The distribution of fibronectin was similar in fetal and adult wounds but tenascin was present earlier in the fetal wound. Fibronectin has several roles in wound healing including acting as a substratum for cell migration and as a mediator of cell adhesion through cell surface integrins. The attachment of fibroblasts to fibronectin is inhibited by tenascin and during development the appearance of tenascin in the ECM of migratory pathways correlates with the initiation of cell migration. Similarly, the appearance of tenascin in healing wounds may initiate cell migration. Tenascin was present in these wounds prior to cell migration and the rapid epithelialisation of fetal wounds may be due to the early appearance of tenascin in the wound.
Distinct effects of cell-cell communication and corticosteroids on the synthesis and distribution of cytokeratins in cultured rat hepatocytes
Authors: Baffet Georges , Loyer Pascal , Glaise Denise , Corlu Anne , Etienne Pierre-Luc , Guguen-Guillouzo Christiane
Published: April 2021

Cytokeratins CK 8 and CK 18 are the two keratins expressed in the liver. They are known to undergo extensive changes in expression with alteration of the hepatocyte phenotype in vitro. In this study, we have investigated the variation in levels of these two cytokeratins in hepatocytes selected from different situations in vivo. The amounts of corresponding transcripts were compared; cytokeratin 8 and 18 mRNAs were present at similar levels in hepatocytes freshly isolated from adult liver and, unexpectedly, from 17-day-old foetuses and newborn rats, whereas they were markedly higher in regenerating hepato-cytes isolated early after partial hepatectomy. In order to investigate whether the different factors that can promote hepatocyte differentiation also produce a similar set of cytoskeletal changes, we have analysed both the expression and the distribution of cytokeratins in hepatocytes under different culture conditions allowing modulation of differentiation. Establishment of cell-cell contacts and addition of glucocorticoids were used as two modulating factors. Coculturing hepatocytes with rat liver epithelial cells (RLEC), which favours active expression of liver-specific genes, resulted in a gradual decline of cytokeratin mRNAs, whereas pure hepatocyte cultures, which exhibit rapid phenotypic changes, expressed increasing levels of CK 8 and CK 18 transcripts. Furthermore, intracellular CK distribution was dramatically modified in parallel: the CK-positive material formed a fine network of fibrils uniformly distributed in the cytoplasm of hepatocytes in pure culture, whereas in cocultured cells CK immunofluorescence appeared principally located at the cellular periphery and it was regularly arranged in long fibrils just beneath the plasma membrane. In contrast, addition of corticosteroids that strongly induces serum albumin synthesis in both pure cultures and cocultures increased the expression of cytokeratin genes in the two systems in a dose-dependent manner, and did not markedly affect their cellular location. These results confirm that the expression level of CKs 8 and 18 varies with the state of differentiation of mature hepatocytes in vivo and in vitro. They demonstrate that both the expression level and cytoplasmic distribution are involved in the morphological changes associated with the differentiated hepatocyte phenotype. In addition, they suggest that cell-cell interactions and glucocorticoids act as distinct regulators of cytoskeletal architecture.
Mikboskofische bt.tckf. in den inneren bad nvn das leben dee gewächse, &C. (Microscopical Glance into the Intimate Structure and Life of Plants. In the form of Popular Lectures.)
Authors: Ross-Massler E. A.
Published: April 2021

The whole is contained in four discourses. In the first the author compares the different modes in which natural history, or the idea contained in it, is comprehended by different classes of minds. To the one it is simply a chamber of mystery—to another a study—to a third a means of climbing to ease and renown—to a fourth a picture-book. To all, he says, it ought to be a “beautiful maternal home, to be a stranger in which should be regarded, in any one, as a loss and shame.” He touches upon the question whether natural history is a real or merely a humanistic science, and decides in favour of the latter, seeing that the homo is still a part of the kingdom of nature—a convenient, but surely a dangerous argument ! He lauds the value of the microscope in the natural sciences ; and then proceeds, in more immediate application to his subject, to show, that plants consist of cells., explaining what is meant by the latter. In the second discourse the theme is continued ; the peculiar forms of cells are described, and then the cell-contents : colouring matter, crystals, nucleus, starch, and the spiral filaments. The ensuing chapter discourses about the vessels and their modifications, and then adverts to the tissues formed immediately from the elementary organs, such as the cuticle with its stomata, hairs, setæ, and scales ; to the structure of the leaf and ligneous stem in the mono- and dicotyledonous plants. The fourth chapter embraces the distinction between animals and plants, with respect to individuality and their various vital actions ; the nutrition of plants and their importance with respect to the habitability of the earth ; and lastly, the alternating relation between animals and plants. The last discourse treats of the root, the changes of matter effected in the interior of plants, the ascent and descent of the nutritive sap, and finally, of the parts belonging to fructification, and of fructification itself.
On the Irritability of Ciliated Cells
Authors: Virchow Rud.
Published: April 2021

Among the many extraordinary circumstances with which the phenomenon of ciliary motion is surrounded, it has not been the least, that we have scarcely been acquainted with a proper excitant of it. Whilst we were able to call the contractile substances into activity by mechanical, physical, and chemical agencies, the founders of the doctrine of ciliary motion, Purkinje and Valentin, could, as regards the cilia, find nothing but means to impede or destroy it. And the influence of mechanical agitation, the only means by which they had seen the failing vibration again become more vigorous, was doubted by Sharpey. Can it be said, therefore, that the ciliary substance is wholly and entirely different from the other contractile substances ?
On the Germination of the Spores of the Uredineæ
Authors: Tulasne M. L. B.
Published: April 2021

The author had previously shown that the spores of the Uredineæ, like the pollen-grains of phanerogamous plants, had a variable number of pores, from which afterwards tubular filaments arose, apparently analogous to those which are the first result of the germination of the spore of a fungus.
Botanical Letters to A Friend
Authors: Unger Dr. F. , Paul Dr. B.
Published: April 2021

Nothing distinguishes our age more than the tendency that exists on the part of those who cultivate Science to diffuse its truths as widely and extensively as possible. The age of conservation in science is. over, and the dream of those who would confine it to our universities, colleges, or royal societies, is for ever dispelled. Much as we are indebted for this condition of things to the practical sagacity of Englishmen, and can boast of a large popular scientific literature in our own language, we have yet to offer a large meed of praise to the professors of science in the German universities, for their attempts to teach beyond the limits of their college walls, and to gain an audience amongst the hitherto despised Philistines. To Humboldt, Liebig, Schleiden, Buff, Moleschott, Schacht, we are indebted for treatises tending to diffuse a knowledge of the highest truths of science, and to these we may now add the name of Unger. These Botanical Letters are an indication of the progress of botanical science. Let any one compare the manuals and introductions formerly put into the hands of students with this volume, and they will see how great has been the advancement in correct observation and generalization within the last few years. Instead of the mere dry details of the forms of the organs of plants, we are introduced to a knowledge of their intimate structure and the laws of their developement ; instead of an absurd comparison of plants and animals, and rude guesses at the functions of the former from a study of those of the latter, we have the physiology of the plant, established upon observations made upon its own structure alone. To all who have attended to the study of the physiology of plants it is known, that the use of the microscope, and that alone, has produced this change and tended to this advancement. The structure of organised bodies and their functions can no longer be studied without this instrument ; and it is only as it is skilfully used that we can expect to attain a true knowledge of the laws which govern the existence of organised beings.
Anatomisch-Histologische Untersuchungen Ueber Fische Und Reptilien
Authors: Leydig Dr. Franz
Published: April 2021

We have more than once had occasion Quar. Jour, of Micros. Science,’ Nos. IV., V.) to refer to the labours of Dr. Leydig, who has done more than any one, of late years, towards extending our knowledge of histology to the lower Vertebrata and to the Invertebrata.
Der Baum. Studien Uber Bau Und Leben Der Hoheren Gewächse
Authors: Sohaoht Von Dr. H.
Published: April 2021

We have already noticed Dr. Schacht’s previous works on the microscope as applied to botanical subjects, and his more important one upon the Plant-cell—and have again the pleasing task of directing our readers’ attention to another from his indefatigable pen—which, like the former, contains a vast amount of matter interesting especially to the microscopic observer.
Contributions to the knowledge of cutaneous diseases, Caused by parasitic growths
Authors: Gudden B.
Published: April 2021

Bateman, following Willan, describes four species under the genus Pityriasis, two of which, P. capitis and P. rubra, varying according to their seat, consist merely in a morbidly increased formation of the epidermis ; P. nigra is unknown to the author, but P. versicolor, as was first noticed by Eichstadt in Froriep’s Notizen, 1846, depends upon a parasitic vegetable growth.
A flora and fauna within living animals
Authors: Leidy Joseph
Published: April 2021

That there are animals which inhabit the bodies of other animals as their natural locality has long been known. Many of these are so obvious as to be popularly recognized under the name of “Worms.” It is, however, only since the extensive employment of the microscope in aiding vision, that any large addition has been made to those generally known. Not only is it found that each species of animal has its peculiar parasitic animal and plant, but every species of animal appears to have a Flora and a Fauna of its own. Formerly a country was necessary to supply the materials of a Fauna or Flora, but with the microscope in hand the stomach of an insect affords abundance of peculiar species of animals and plants for such a purpose. Dr. Leidy’s work is not an account of all the species of plants found in living animals, but an account of certain new genera and species of plants discovered by himself in the stomach and intestines of a few species of insects. In an introduction, Dr. Leidy refers to the plants and animals of the human body. These are treated of at length in the works of Dujardin,* Diesing,-†- and Robin.‡
On the construction of the compound achromatic microscope
Authors: Brooke Charles
Published: April 2021

After briefly adverting to the ordinary phenomena of reflection, the lecturer illustrated those of refraction by a moveable diagram, which readily explained the total reflection of a ray of light incident on the common surface of two media, at an angle greater than the critical angle, corresponding to which the angle of refraction is 90°.
On closterium lunula
Authors: Osborne S. G. , Hogg Jabez
Published: April 2021

“I Have now examined with great care more than one hundred specimens of C. Lunula. I will give you the result as impressed upon my own mind.
On some new or little-known Diseases of Plants, caused by Fungi
Authors: Braun Alex , Caspary  , Bary Anton De
Published: April 2021

In the introductory part of this brochure, Dr. A. Braun says that, “As the history of the civilization of the human race has its dark side in the development of many obstinate social evils which accompany the march of advancing civilization, so also has horticulture and agriculture, together with the bright, their dark side. There are certain diseases to which plants, in the state of cultivation show themselves to be more obnoxious than when they are in their natural localities, and subject to the original conditions requisite for their flourishing. That this dark side fully deserves the attention of the gardener and of the farmer, is obvious, from the incalculable evils that ensue upon the mysterious and unexpected appearance of one of these vegetable plagues. The more difficult it appears to investigate the causes of these diseases, and to discover means by which they may be arrested or prevented, so much the more are they worthy of profound study.”
On a “Black Fur on the Tongue.”
Authors: Coblenz Eulenberg
Published: April 2021

The author relates that in the preceding year a child, two years old, was brought to him whose tongue was covered with a perfectly black coating. The organ, from the tip to the back, appeared as if it were smeared with ink ; and at first sight the supposition necessarily entertained was, that the child had licked some black object, or had swallowed a coloured liquid. Except a slight diarrhœa, the boy presented no other morbid symptoms. For his age, he. was well developed, and had never had any important illness. The author’s immediate treatment was confined to washing the tongue with vinegar and water.
Untersuchungen ueber die Entwicklungs-Geschichte der Mikroskopischen Algen und Pilze
Authors: Cohn Dr. F.
Published: April 2021

The importance of the study of unicellular organisms, as leading in the most ready and complete way to a knowledge of the “cell,” the foundation of all scientific acquaintance with the real nature of plant life is so obvious, as to have attracted a great number of followers.
Principles of Comparative Physiology
Authors: Carpenter W. B.
Published: April 2021

Although it be an ample apology for the use of the microscope, that he who records a new observation by its aid has added another fact to science, yet we would fain hope that all who use this instrument are more or less impressed with the truth, that by its employment large departments of human knowledge are being moved on. If we wanted an apology for the use of the microscope, we could not do better than point to the works of the learned and laborious President of the Microscopical Society on the various branches of the great science of Biology. Let any one compare the manuals of Physiology that were in use twenty-five years ago with the last editions of Dr. Carpenter’s beautiful volumes, and they will see not only how our knowledge of the laws which govern vital phenomena has advanced, but they will see that it has been mainly by the aid of the microscope. They will see too in Dr. Carpenter’s volumes how the labours of the humblest observers become in time part and parcel of the great body of special and general facts, which constitute the principles of science. This should be an encouragement to all to persevere in a course of observation, and to record what they have observed. Few perhaps know the whole value and significance of the facts which are presented to their senses ; but if they record them, they become appropriated by those whose special and peculiar gift it is to generalise, and thus to give a form and body to science. Of modern writers and workers few possess this gift to so great an extent as Dr. Carpenter, and he may be justly regarded as the most successful exponent of Physiological science in this country, and one of our most elegant scientific writers. The volume, whose name stands at the head of our article, is intended as a companion to two others, the ‘Principles of Human Physiology’ and the ‘Principles of General Physiology.’ The latter work, which is not yet published, together with the present volume, formed the basis of the author’s ‘ Principles of Physiology, General and Comparative,’ which will henceforth cease to appear as a single volume.
The Microscope and its Application to Vegetable Anatomy and Physiology
Authors: Schacht Dr. Hermann , Currey Frederick
Published: April 2021

The fact of this book having reached a second edition justifies the good opinion we have expressed of it on two previous occasions. Mr. Currey has taken the opportunity of adding some new matter, which has very considerably improved this edition. Four chapters have been added at the beginning of the book; the first of which relates to some elementary principles of optics essential to a proper comprehension of the microscope; the second contains a description of different kinds of English microscopes, including as far as is necessary the details of their different parts; the third contains an account of the accessory apparatus and chemical reagents necessary for microscopical investigations in botany; and the fourth relates to the preservation of specimens. Besides these chapters by the editor, Dr. Schacht has furnished a quantity of new matter in manuscript, being the result of his investigations since the last German edition of his work was published in 1852.
Lettsomian lectures on pulmonary consumption
Authors: Thompson Theophilus
Published: April 2021

This work consists of three lectures devoted to the subject of pulmonary consumption and its treatment. In the first lecture there are some very good remarks on the microscopic appearances afforded during the progress of tuberculous disease of the lungs. It has oftentimes been denied that the microscope is of any value in the diagnosis of tubercle; and on this subject we subjoin the remarks of Dr. Thompson, whose opinion no one will doubt is that of a thoroughly practical man: —
Royal Society. Micro-chemical Researches on the Digestion of Starch and Amylaceous Foods
Authors: Ayres Philip Burnard , Bishop John
Published: April 2021

After some general historical remarks on the methods hitherto employed in the investigation of the complicated phenomena of the process of digestion, the comparatively small results obtained by chemical analysis of the contents of the stomach, intestinal canal, and of the evacuations, by Tiedemann and Gmelin, Berzelius, and others, the author proceeded to demonstrate the necessity of a minute examination of the contents of the alimentary canal by the microscope, and such chemical tests as we possess for the determination of the changes of such articles of food as exhibit definite structure.
Observations on the practical application of the microscope
Authors: Hepworth J.
Published: April 2021

There are yet some parties in the medical profession who are sceptical as to the utility of the microscope. I have found it occasionally of practical importance; and perhaps if I mention a few cases, it may not be uninteresting to the medical readers of the ‘Journal.’
On the actinophrys sol
Authors: Weston J.
Published: April 2021

Having during the last two or three months met with a plentiful supply of Actinophrys Sol, and fortunately also a most unusual deficiency of professional calls upon my time, I have been enabled to pay these little creatures considerable attention, not, I hope, quite fruitlessly, since the description I am about to give of some of their peculiar habits will, I think, be novel.
On the impregnation and germination of algæ
Authors: Pringsheim M.
Published: April 2021

Having thus fully described the mode of origin of what may be termed the sexual organs in Vaucheria, the author proceeds to describe the process of impregnation as it takes place in the Fucaceæ, and which he finds to be of a precisely analogous nature. Adverting to Thuret’s observations and experiments, which showed that unless brought into contact with the antheridia of the male plant, the spores of these plants invariably perish without germination, he proceeds to relate his own researches on the same subject in Fucus vesi-culosus. The result was fully to confirm Thuret’s statements.
On the course of the amyloid degeneration
Authors: Virchow Rudolph
Published: April 2021

In former communications on the subject of “amyloid degeneration” the Author was able to adduce, as instances of the affection, besides the corpora amylacea in the nervous system, only the waxy degeneration of the spleen, liver, and kidneys; but since then some more recent cases have afforded him the opportunity of extending his researches, and of making, as he thinks, a very important advance in the knowledge of the remarkable changes included under the term.
The Practical Use of the Microscope
Authors: Hepworth J.
Published: April 2021

In making a post-mortem examination of a man about 63 years of age, who had laboured under gastric disease for two or three years and was extremely emaciated and dropsical, I found the stomach small, and containing about an ounce of yellowish mucus; there was no scirrhus, but the rugæ were thickened and more raised than natural, ecchymosis had occurred in different parts of the inner lining, but principally on the elevated ridges of the rugæ; the mucous lining over two or three of these spots, had given way, leaving a small jagged ulcer. On examining one of these points I found that the vessels retained their form (although quite bare), except one or two, which had contracted and formed a knob about the of an inch in diameter at the point of rupture. There was a cicatrix, three quarters by five eighths of an inch in diameter, in which the muscular coat was wanting, but the mucous covering appeared to have been reproduced. On examining the mucus, it did not contain Sarcina ventriculi as I had anticipated, but some crystals of oxalate of lime (which I never met with in the stomach before), abundance of exudation corpuscles and what I conceive to be a vegetation (vide fig. 1). The corpuscles appear to have been the nidi of these formations, as I observed them in different stages of progress, as though each granule of the corpuscle supported a single cell, or plant; these becoming elongated, and so numerous as almost to hide the whole of the corpuscle from view.
The Structure of the Eye of the Lobster.
Authors: T. Newton Edwin
Published: April 2021

(With Plates XVI and XVII.)
On the Chromatological Relations of Spongilla Fleviatilis
Authors: Sorby H. C.
Published: April 2021

I Had long been anxious to examine fresh specimens of Spongilla, since the old and dry specimens which I had studied clearly showed that the colouring matters had been greatly altered. At length, through the kindness of Mr. E. Ray Lankester, I was able to investigate the subject in a perfectly satisfactory manner. I had previously examined some of the marine sponges growing on the coast of Devonshire, which are often of a fine orange colour, but sometimes have a well-marked green tint. In the natural state these did not show the band in the red characteristic of chlorophyll; and, though when dried and digested in carbon bisulphide the solution contained a small quantity of chlorophyll, yet I could not be certain that it had not been derived from a small portion of some alga accidentally enclosed in the sponge. The exact nature of the green substance is therefore still open to some slight doubt. The chief coloured constituent was an orange substance soluble in carbon bisulphide, which, when so dissolved, had a pink tint in dilute solution. The spectrum had no detached narrow absorption-bands, but cut off the whole of the green and blue, and when diluted allowed the blue to pass rather more readily than the green. I was not able to distinguish any difference between it and an orange-coloured substance found in the eggs of the crab, but it would be premature to say that the two are identical. There is also an orange colouring matter found in the soft parts of some species of Cardium, closely allied, though not identical, with these, and on the whole it seems pretty clear that the coloured compounds found in some marine sponges are either identical with or closely related to those met with in animals, and unlike those occurring in the higher classes of plants. Fungi do, indeed, sometimes contain very closely allied substances, but I do not yet know any certainly identical. At all events, when looked upon from a chromatological point of view, such sponges are closely related to animals, or to those plants which, like them, are nourished by complex chemical compounds, and cannot be supported by merely mineral substances, like the more perfect plants.
On the Invaginate Planula, or Diploblastic Phase of Paludina vivipara
Authors: Lankester E. Ray
Published: April 2021

At the end of last summer I had an opportunity of examining some embryoes of Paludina, in the laboratory of Exeter College, Oxford.
Observations on the Structure of the Spleen
Authors: Klein E.
Published: April 2021

The structure and function of the spleen has at all times been one of the most favourite subjects of discussion with histologists. It is chiefly its great importance in pathology that has made it an object of repeated investigation. The spleen is so complicated an organ, and its investigation combined with so many difficulties, that it is no wonder that even the principal points with regard to its structure are not yet definitely settled, being still a matter of controversy. Experiment has done very little hitherto with reference to the function of the spleen ; the whole doctrine of its function rests, therefore, almost entirely on anatomical investigation. Generally the spleen is regarded as to a certain extent analogous to a lymphatic gland, in virtue of its containing masses of adenoid tissue, first in the sheath of arterial branches, and secondly as special elliptical or spherical collections—the well-known Malpighian corpuscles—in connection with small arteries. From this and from the fact that the trunk of the splenic vein always contains in the normal condition an abundance of lymphoid cells or colourless blood-corpuscles, it has been concluded that these cells are produced in the spleen.
Note on a Pink-coloured Spirillum (Spirillum rosaceum)
Authors: Klein E.
Published: April 2021

On the 26th December of last year Dr. Mackellar, of the Fever Hospital at Stockwell, placed for me a small quantity —about half a drachm—of fresh faecal matter, obtained from a recent case of enteric fever, in a bottle containing about four ounces of water. The sediment, which was of a yellowish-white colour, contained, when examined under the microscope, very numerous, bright, highly refractive, large (spherical) Micrococci, either isolated or in dumb-bells, or forming smaller or larger masses of Zooglcea.
On the Structure of the Proboscis of Ophideres fullonica, an Orange-sucking Moth
Authors: Darwin Francis
Published: April 2021

It must be premised that the fact of some Lepidoptera piercing vegetable tissues for the purpose of obtaining the juices is not a new one. In his ‘Fertilisation of Orchids’ pay father shows that the lining membrane of the nectaries of certain orchids are bored through in this way. Moreover, Mr. R. Trimen informed my father that, at the Cape of Good Hope, a great deal of fruit is thus injured by Lepidoptera.1
On a Polystomatous Condition of the Hydranths of Cordylophora lacustris
Authors: Price Hugh
Published: April 2021

Specimens of the beautiful hydroid polyp Cordylophora were brought by me last summer from the Victoria Docks for the use of the class of practical zoology at University College, London. Professor Ray Lankester drew my attention to certain abnormal-looking hydranths amongst these specimens which appeared to possess a number of supernumerary oral cones. I isolated some of these abnormal specimens and made them the subject of further study.
Contributions to the History of the Germinal Vesicle, and of the First Embryonic Nucleus
Authors: Beneden Edouard Van
Published: April 2021

I have had the honour of presenting to the Academy a summary exposition of the results of my researches on the maturation of the ovule, the fecundation and earliest phenomena in the embryonic development of the rabbit, up to the moment of the appearance of the primitive streak more especially. I have made known those of my researches which establish the disappearance of the germinal vesicle, the formation of the directive bodies (Richtungsbläschen of Fritz Müller), and the appearance of the first embryonic nucleus. The recent publication of the researches of Auerbach,1 Bütschli,2 and Strasburger,3 on the formation and division of the nuclei of cells, led me, in the course of my researches on the development of mammalia, to investigate very specially how the first nucleus of the embryo appears and how cells multiply in the embryonic laminæ. Long before I became acquainted with these researches, I had observed that the germinal vesicle of the rabbit disappears, independent of fecundation, and that the disappearance of this element is the indication of the complete maturity of the ovum.
A New Process for Examining the Structure of the Brain. With a review of some points in the Histology of the Cerebellum
Authors: Sankey H. R. Octavius
Published: April 2021

The methods usually adopted in the microscopical examination of the brain have all proved in my hands more or less unsatisfactory. I find that when thin sections of hardened brain are cut and stained, the dye does not sufficiently differentiate the various structures so as to render their form and arrangement obvious, while in teased preparations the shape of the cells, the connection of their processes, and the fibres of the brain are just as likely to be torn to pieces as to be separated from the substance which surrounds them.
On the Development of the Ova and Structure of the Ovary in Man and other Mammalia
Authors: Foulis James
Published: April 2021

Contents.—Introduction. The Ovary of the Kitten. The Human Ovary: (a) Nature of the germ epithelium; (b) The relation of the germ epithelium to the peritoneal epithelium; (c) The manner of inclusion of the primordial ova and germ epithelial corpuscles in the stroma of the ovary; (d) Development of the egg clusters; (e) The development of the membrana granulosa. General observations on the development of the membrana granulosa in adult ovaries. General conclusions.
On the Structure of Muscular Fibre
Authors: Thin G.
Published: April 2021

In order that the value of the preparations which it is the object of this paper to describe may be properly estimated it is necessary to refer the reader to a paper I published in ‘The Edinburgh Medical Journal’ for September, 1874, On the Minute Anatomy of Muscle and Tendon, and especially to the figures by which it is illustrated. For the sake of completeness I will, however, give here a short summary of the results of my investigations up to the time when that paper was written.
An Account of the Recent Researches into the History of the Bacteria, made by, and under the direction of, Prof. Cohn.1
Authors: Bell F. Jeffrey
Published: April 2021

In the April number of the 13th volume of this Journal (1873), an account was given of the first series of observations on Bacteria which Professor Cohn had published in his valuable ‘Beitiägezur Biologie der Pflanzen1 (Heft 2) ; in the 3rd Heft, published last year, the subject is continued by Cohn, in addition to whom Eidam, working in his laboratory, gives an account of certain experiments made on these interesting organisms. Since the publication of the previous paper the discussion concerning spontaneous generation has changed in aspect ; Dr. Burdon Sanderson has given an account of several Bacterioid forms, in his Reports to the Medical Officer of the Privy Council, and Professor Ray Lankester has called the attention of readers of this Journal to the subject by his very interesting account of “a peachcoloured Bacterium.” To the wide interest exhibited in these forms Cohn briefly refers, but mentions at greater length the work of Billroth, published by George Reimer, of Berlin, in 1874.1 I shall try to give in the following pages an account of these two new papers, but must refer all who are really interested in the matter from whatever point of view, philosophical, botanical, or pathological, to the originals themselves, assuring them that diffuseness will not be found to be a characteristic of this memoir. Notwithstanding Billroth’s work, Cohn holds firmly to his original position, that the Bacteria should be arranged in genera and species, and not united into a single polymorphous species— Coccobacteria septica (Billroth), as has happened to all the forms described by him, with the exception of Spirillum and Spirochæte, under the hands of Billroth. Readers of this Journal will remember that Mr. Lankester speaks of B. rubescens as a Protean species. Against such a view Cohn argues that the changes of form are not fully proved, nor does he think that such a way of looking at these organisms will be as conducive to progress in our knowledge as his more objective method. With so much byway of introduction we will proceed to the consideration of the various forms which Cohn examines, one by one ; it will I think conduce to clearness, if we follow his example.
White Cement for Final Coating in Microscopic Mounting
Authors: Richardson B. Wills
Published: April 2021

A white cement for final coating in microscopic mounting, and one which admits of being used cold, has been employed for some years abroad. It is known as “Ziegler’s White Cement.”
Note on a Method of Preparing the Cornea
Authors: Klein E.
Published: April 2021

In his studies on inflammation, Stricker (‘Medizin. Jahrbücher,’ 1875) uses caustic potash as a means of producing keratitis. The centre of the cornea of a kitten is touched with a pointed stick of caustic potash, and after the lapse of twenty-four to forty-eight hours—according to the required stage of inflammation—the cornea is treated with lunar caustic, and then left to stand in water acidulated with acetic acid.
An Account of Professor Strasburger’s Observations on Protoplasm
Authors: Vines Sydney H.
Published: April 2021

In spite of the numerous researches which have been undertaken of late years in order to gain some knowledge of the properties and intimate structure of that substance which, from its universal occurrence in living organisms, has been termed the “physical basis of life,” and to which Hugo von Mohl gave the name “Protoplasm,” our information is still quite insufficient to enable us to form any satisfactory hypothesis upon which the so-called vital phenomena exhibited by this substance might be explained. In these “studies” Professor Strasburger gives some account of his observations in this direction.