bluuebunny/crossref_metadata_2025 huggingface dataset:
The polarized epithelial phenotype is dominant in hybrids between polarized and unpolarized rat thyroid cell lines
Authors: Zurzolo Chiara , Gentile Raff Aele , Mascia Anna , Garbi Corrado , Polistina Claudio , Aloj Luigi , Awedimento Vittorio Enrico , Nitsch Lucio
Published: April 2021

We have studied the expression of cell polarity in hybrids between two rat thyroid epithelial cells: FRT and FRTL-5. FRT cells are polarized but do not express tissue-specific properties, FRTL-5 are unpolarized and express many thyroid-specific genes. A pool of 170 hybrid clones and five independent clones were characterized. The chromosome complement was that expected from 1:1 fusion of the parental cells. No chromosome loss was observed for several generations. All hybrids were polarized as judged from: (1) morphology, (2) transepithelial resistance, (3) preferential secretion of several proteins either through the apical (e.g. thyroglobulin) or through the basolateral pole, and (4) basolateral trapping of iodide. On the other hand, the expression of thyroid-specific markers: thyroglobulin synthesis and secretion, trapping of iodide, thyrotropin-dependent growth and expression of specific membrane antigens, were greatly reduced or inhibited in the pool and in the isolated clones. We also found that reduction of thyroglobulin synthesis was correlated with the loss of activity of the trans-acting factor TgTF1. We conclude that cell polarity, a property of FRT cells, is dominant in the hybrids whereas thyroid differentiation is recessive.
Behaviour of nucleolar proteins in nuclei lacking ribosomal genes: A study by confocal laser scanning microscopy
Authors: Hernandez-Verdun D. , Robert-Nicoud M. , Geraud G. , Masson C.
Published: April 2021

The behaviour of nucleolar proteins in cycling PtK1 cells and in micronuclei with or without NORs was investigated by immunofluorescence using antibodies from autoimmune sera and confocal laser scanning microscopy. These antibodies were shown by electron microscopy to recognize antigens confined to only one of the three basic nucleolar components: fibrillar centres (FC), dense fibrillar component (DFC) and granular component (GC). Serial optical sections allowed us to determine the three-dimensional organization of these components in the nucleolus of cycling cells. Furthermore, clear differences were found in the distribution of the various antigens in micronucleated cells. Three patterns could be observed: (1) the FC antigens were found mainly in the nucleoli, but also in varying amounts in the dots; (2) surprisingly, the DFC antigens were found to accumulate preferentially in the dots; (3) the GC-specific marker stained intensively the nucleoli as well the dots. The results are interpreted with regard to possible mechanisms for targeting nucleolar proteins to the site of nucleolar formation.
Nuclear localization of an o-glycosylated protein phosphotyrosine phosphatase from human cells
Authors: Meikrantz William , Smith Douglas M. , Sladicka Melissa M. , Schlegel Robert A.
Published: April 2021

Histochemical staining of immunoprecipitates of p65, a component of human M phase-promoting factor, identified the molecule as having phosphatase activity. The enzyme, purified 3400-fold from mitotic cell extracts by (NH^SCL precipitation, DEAE chromatography, and immunoaffinity chromatography on immobilized anti-p65 IgG, was inhibited by Zn 2+ and Na 3 VO 4 but not NaF or β-glycerophosphate; 32 P-labeled poly(Glu, Tyr) was more efficiently dephosphorylated than phosphorylated histone or phosphorylase a. Indirect immunofluorescence showed most of the phosphatase to be localized in the nucleus of interphase cells, with a fine, granular distribution unaltered by detergent extraction; in mitotic cells, p65 was localized on chromosomes. ELISA of subcellular fractions confirmed this localization. Immunoreactive p65 was recovered from immobilized wheat germ agglutinin (WGA) upon elution with N-acetylglucosamine; similarly, WGA recognized immunoaffinity-purified p65 on blots. Alkaline hydrolysis of blotted protein prevented WGA binding, indicating that phosphatase p65, like a small group of other nuclear proteins, contains O-linked carbohydrate terminating in N-acetylgluco-samine.
A perichromosomal region contains proteins phosphorylated during mitosis in Xenopus Laevis cells
Authors: Dilworth Stephen M.
Published: April 2021

An antibody that recognizes the phosphorylated form of nucleoplasmin has identified another nuclear protein whose antigenic form is regulated in a mitosis-specific manner, with a dramatic increase in binding occurring in all mitotic cells. The protein is localised around the periphery of condensed chromosomes during mitosis in a manner analogous to another nucleoplasmin-related polypeptide NO38. Mitosis-specific expression of the antigenic site is dependent on phosphorylation of the polypeptide; binding of the antibody is dramatically reduced byprior incubation of the polypeptide with phosphatases. Migration on SDS-PAGE suggests that the protein has an exceptionally large relative molecular mass, in excess of 400000. The probable mitosisspecific phosphorylation and location of this antigen suggests a subcell ular storage mechanism for proteins during mitosis.
Vanadate inhibits both intercellular adhesion and spreading on fibronectin of BHK21 cells and transformed derivatives
Authors: Edwards J. G. , Campbell G. , Grierson A. W. , Kenn S. R.
Published: April 2021

Both intercellular adhesion and spreading on fibronectin of BHK21 hamster cells are inhibited by vanadate at concentrations that cause specific regulatory effects rather than general metabolic inhibition. Inhibition of aggregation of these cells in suspension (half-maximal in 10−5M vanadate) is rapid and reversible. The extent of inhibition, and its decline with culture age parallel inhibition by agents that depolymerize microtubules.

Vanadate also reversibly inhibits spreading of both BHK cells and transformed derivatives on fibronectin. If 10−4 M vanadate is added to BHK cells that have spread in its absence, they remain spread,but transformed derivatives are sensitive to rounding by vanadate at 10−6M.

The mechanisms by which vanadate inhibits both intercellular adhesion and spreading are unknown, and may be different for the two phenomena. Possible sensitive targets include cytoplasmic dynein for the former, and protein tyrosyl phosphatase for the latter.
Production of scatter factor by ndk, a strain of epithelial cells, and inhibition of scatter factor activity by suramin
Authors: Adams Josephine C. , Furlong Robert A. , Watt Fiona M.
Published: April 2021

ndk are a strain of human epidermal kératinocytes that do not undergo terminal differentiation and which grow as single cells rather than compact colonies. We show that ndk are motile and secrete an epithelial scatter factor that has the same biochemical and immunological properties as the scatter factor previously purified from ras-transformed 3T3 fibroblasts. We have found that suramin, a polyanionic detergent, will reverse the activity of scatter factor from either cell type in the standard MDCK activity assay. When added to ndk cultures, suramin causes the cells to grow in coherent patches. This morphological change is accompanied by alterations in the distribution of actin and integrins, but not by stratification or terminal differentiation. The effect is reversed upon removal of suramin. We propose that the motile phenotype of ndk is due, at least in part, to autocrine production of scatter factor and that suramin may be useful for further studies of scatter factor binding to the cell surface.
Addition of protease inhibitors to culture medium of neuroblastoma cells induces both neurite outgrowth and phosphorylation of microtubule-associated protein MAP-1B
Authors: Diaz-Nido J. , Armas-Portela R. , Avila J.
Published: April 2021

The addition of two synthetic peptides with antiprotease activity to the culture medium of mouse neuroblastoma cells results in the promotion of neurite outgrowth. One of these peptides has a sequence corresponding to the reactive center of protease nexin-1 and inhibits both trypsin and thrombin. Its effect on neuroblastoma cells is similar to that found on serum withdrawal from the culture medium, giving rise to cells with one or two long neurites, and is reversed upon the addition of thrombin to the culture medium. The sequence of the other peptide is present in one of the precursor proteins of the main component of the amyloid plaques of Alzheimer’s disease patients’ brains, and corresponds to protease nexin-2. It can inhibit trypsin but fails to inhibit thrombin at low doses. Its effect on neuroblastoma cells is slightly different from that observed after serum deprivation, as a significant proportion of stellate cells, with short and branched neurites, is observed. An increase in the phosphorylation of microtubule-associated protein MAP-1B, which accompanies neurite outgrowth induced by serum deprivation, is also observed upon addition of the two antiprotease synthetic peptides, although the nexin-2 (amyloid) peptide induces a less marked increase in phosphorylated MAP-1B than does the nexin-1 peptide. These results may be correlated with the different antiprotease activities of both synthetic peptides, thus suggesting a role for a balance between trypsin-like and thrombin-like proteases and their inhibitors in eliciting neurite outgrowth under normal and pathological conditions.
Differential behavior of centrosomes in unequally dividing blastomeres during fourth cleavage of sea urchin embryos
Authors: Holy Jon , Schatten Gerald
Published: April 2021

The fourth cleavage in sea urchin embryos is unequal and represents an initial step in cell differentiation: vegetal blastomeres divide to produce micromeres, which are precursors of the skeleto- genic mesenchyme, and macromeres. The mitotic spindles of these unequally dividing cells are peripherally located and lie orthogonal to the vegetal pole plasma membrane; the aster of the micromere pole is closely apposed to the plasmalemma and presents a characteristic flattened profile. In order to investigate the role of centrosomes in the generation of the asymmetric vegetal spindle at fourth cleavage, structural dynamics of centrosomes in both equally and unequally dividing blastomeres were compared using immunofluorescence methods. Quantitation of immunofluorescence and three-dimensional reconstruction techniques demonstrate that micromere centrosomes differ from macromere centrosomes in two respects: (1) micromere spindle poles contain less centrosomal material than macromere poles, and (2) micromere centrosomes undergo a specific filiform elongation during late anaphase and telophase. The behavior of micromere centrosomes suggests that a unique spindle pole event, involving interactions of the microtubular cytoskeleton, centrosome and cell cortex, occurs during the process of unequal cleavage of vegetal blastomeres.
Studies on the ejection properties of asters: astral microtubule turnover influences the oscillatory behavior and positioning of mono-oriented chromosomes
Authors: Ault Jeffrey G. , Demarco Anthony J. , Salmon Edward D. , Rieder Conly L.
Published: April 2021

The position of a mono-oriented chromosome changes as it oscillates to and from the pole to which it is attached. Such oscillatory behavior reveals that the net force on a mono-oriented chromosome is constantly changing. Fluctuations may occur in both the polewardly directed force acting at the kinetochore and the opposing outwardly directed force associated with the aster. We have examined the ejection properties of the aster –as well as the oscillatory behavior and positioning of monooriented chromosomes –in relation to astral microtubule turnover. We treated cells containing monopolar spindles with drugs that affect microtubule turnover, either by promoting the depletion of dynamically unstable astral microtubules (nocodazole and colcemid) or by augmenting their numbers and stability (taxol). Both types of drugs stopped the oscillatory behavior of mono-oriented chromosomes within seconds. The final position of the chromosomes depended on how microtubule turnover was affected. In the case of nocodazole and colcemid, non-kinetochore astral microtubules were depleted first and the kinetochore-to-pole distance shortened. In these cells chromosome fragments generated bylaser microsurgery were no longer expelled from the center of the aster. By contrast, with taxol the number of non-kinetochore microtubules increased and the astral ejection force became stronger as shown by the finding that the chromosomes moved away from the pole to the periphery of the monaster. Moreover, arms severed from chromosomes at the periphery of the taxol monaster failed to move further away from the aster’s center. From these observations we conclude that the oscillatory movements and changing position of a mono-oriented chromosome relative to the pole are mediated by changes in the number of astral microtubules. The dynamic instability of astral microtubules that leads to a rapid turnover may contribute to the astral ejection force by allowing the continual growth of microtubules out from the aster. Growing astral microtubules may exert a pushing force that their rigidity maintains until their depolymerization.
The role of the flagellar transition region: inferences from the analysis of a Chlamydomonas mutant with defective transition region structures
Authors: Jarvik Jonathan W. , Suhan Joseph P.
Published: April 2021

Thin-section electron microscopy of the Chlamydomonas reinhardtii mutant vfl-2 revealed striking defects in the transition region between basal body and flagellum. In place of the highly organized transition cylinders and stellate fibers characteristic of wild type, variable quantities of poorly organized electron-dense material were present. In many cases the transition region was penetrated by central pair microtubules that passed from the axoneme into the basal body. On the basis of these observations we propose that an important function of the structures present in the normal transition region is to physically exclude the central pair microtubules from the basal body.

The transition region is the site of flagellarautotomy –the process by which doublet microtubules are severed and flagella are released from the cell. It has been claimed that autotomy is caused by contraction of the centrin-containing stellate fibers, resulting in the mechanical severing of the doublet microtubules and a concomitant reduction of the diameter of the axoneme adjacent to the abscission point. Our observations do not support this claim in that vfl-2 cells, which lack organized stellate fibers, display effective autotomy unaccompanied by detectable narrowing of the axoneme.
Binding of latent and high M
r active forms of stromelysin to collagen is mediated by the C-terminal domain
Authors: Allan J. A. , Hembry R. M. , Angal S. , Reynolds J. J. , Murphy G.
Published: April 2021

A specific high-titre polyclonal antiserum to recombinant human prostromelysin was raised in a sheep and shown by immunoblotting to detect latent prostromelysin, high and low Mr active forms and the C-terminal domain. This antiserum was used to demonstrate by indirect immunofluorescence that latent and active high Mr prostromelysin bind to reconstituted collagen fibrils, and to other extracellular matrix components in tissues ex vivo but that active low Mr stromelysin does not Isolation of the C-terminal domain was carried out to demonstrate that stromelysin binding was through this domain.

By use of an antiserum to the tissue inhibitor of metalloproteinases (TIMP) it was shown that TIMP is unable to bind to reconstituted collagen fibrils. TIMP, however, will bind when active high Mr stromelysin is present but not if latent prostromelysin is bound.

We conclude that stromelysin has different binding specificities from those previously documented for collagenase; only active collagenase binds to reconstituted collagen fibrils. However, TIMP binds to the active forms of both stromelysin and collagenase when these are bound to the collagen fibrils. These results have important implications for the interpretation of immunolocalization data in establishing the roles of metalloproteinases and their inhibitors in vivo.
Structural analysis and expression of human desmoglein: a cadherin-like component of the desmosome
Authors: Nilles Laura A. , Parry David A. D. , Powers Eric E. , Angst Brigitt D. , Wagner Rita M. , Green Kathleen J.
Published: April 2021

Desmosomes are adhesive cell junctions found in great abondance in tissues that experience mechanical stress. The transmembrane desmosomal glycoproteine have been proposed to play a role in cell adhesion; desmoglein I (DGI) is a major member of this class of desmosomal molecules. However, evidence supporting a role for DGI in cell adhesion or in the plaque is lacking. In order to begin to understand DGI function we have identified human cDNA clones encoding the entire mature polypeptide of 1000 amino acids. Our data suggest that like the bovine DGI molecule human DGI is highly related to the calcium-dependent class of cell adhesion molecules known as cadherins. Four related extracellular domains located in the amino-terminal domain of the molecule contain putative calcium binding sites originally identified in the cadherins. The highest degree of similarity between human N-cadherin and human DGI, and likewise between bovine DGI and human DGI, is greatest in the most amino-terminal extracellular domain. This suggests a conserved functional role for the extracellular domains, perhaps in calcium-mediated cell adhesion. The cyto-plasmic portion of the molecule contains a cadherinlike region and, like bovine DGI, a carboxy-terminal tail that is not present in the cadherins, comprising three additional domains. One of these contains a novel repeating motif of 29±1 residues, first identified in bovine DGI. Each of the highly homologous repeating units is likely to consist of two β-strands and two tums with special characteristics. Five amino acids that are identical in bovine and human DGI lie in the second of the two predicted β-strands, and intriguingly contain putative target sites for protein kinase C. On the basis of structural analysis, a model predicting the disposition of human DGI domains in the desmosome is proposed.

Northern analysis suggests that unlike bovine epidermis, which expresses a single mRNA of reported size ∼7.6kb, human foreskin and cultured keratinocytes display a complex pattern with bands of —7.2, 4.0 and 3.0 kb. Each of these cross-hybridizing mRNAs is coordinately expressed in normal human keratinocytes in response to long-term culture and increased calcium.
Notes on the structure of oscillatortæ, with a description of a new species, possessing a most remarkable locomotive power, not cilia
Authors: D’Alquen F.
Published: April 2021

The study of the structure of the Oscillatoriœ is particularly interesting, from the fact that we may not unreasonably expect to find in it a key to the singular motion from which they have received their generic name, and which now, for more than a century,* has formed an object of curiosity and interest to the microscopist without having received as yet a satisfactory explanation. In one species at least, I think, I have been able to make out the leading features of its structure and the mechanism of its locomotion. The description of this, to me, new species I wish to preface by a few observations, containing some new facts regarding the structure of Oscillatoria in general, which may, perhaps, interest some of your readers ; in doing so, it will, however, not be necessary to refer to the general character of these interesting organisms, as they must be familiarly known to every one who is in the habit of using the microscope, and therefore I plunge at once in medias res.
Notes on the siliceous cell of diatomaceæ
Authors: Ralfs J.
Published: April 2021

The few remarks now offered to the British Association, “upon the siliceous cell formed within the frustules of several Diatomaceæ,” have been written rather to stimulate the researches of my fellow-students, and to elicit their opinions, than to communicate any new facts.
On the ossification of the primordial cartilage
Authors: Baur A.
Published: April 2021

A Microscopical analysis of the changes which take place in the ossification of cartilage has two questions to resolve: First, in what way does the peculiar structure of osseous substance arise from the so widely different structure of cartilage ? and, secondly, in this process, in what relation do the elements of the cartilage stand towards those of the bone? The latter question especially, since it has become known that bone may be formed without any pre-existing cartilage, has acquired redoubled interest.
A monograph of the fresh-water polyzoa
Authors: Allman Geo. J.
Published: April 2021

To the well-known and invaluable series of Monographs by Alder and Hancock, Forbes, Baird, and Darwin, published under the auspices of the Ray Society, we have to announce the addition of the long-expected work of Professor Allman, on the ‘Fresh-water Polyzoa, including all the known species, both British and Foreign.’
Catalogue of Desmidiacece
Authors: Ball R. , Archer Wm.
Published: April 2021

The following list of the Desmidiaceæ which I have found about the “Feather-bed” and “Seechon” mountains, near Dublin, is not, of course assumed to be a complete list. It is, however, a perfect one (with, perhaps, the exception of the genus Pediastrum) of the species I have met with in my limited experience; and I have no doubt but subsequent search will very much extend it. I have ventured to append to each species an opinion as to its frequency or rarity, which, I need hardly state, is to be interpreted as the result of my own experience only in a limited district. Some of those I have marked as rare may ultimately prove frequent. I am inclined to corroborate an observation made in Mr. Ralfs’ beautiful f Monograph,’ as to the non-occurrence of the same species in the same pools from year to year. For instance, in the year 1855, a certain pool produced Didymoprium Borreri in great abundance. During 1856 I could not find a single specimen of that species; but its place was taken by a considerably less abundant development’ of Hyalotheca mucosa.
On a New Polyzoon, “Victorella Pavida,” From Ike Victoria Docks
Authors: Kent WM. S.
Published: April 2021

In November, 1868, I briefly referred, in the pages of ‘Science Gossip,’ to a representative of the Ctenostomatous Polyzoa, taken by myself in the brackish waters of the Victoria Docks.
Note on the Distribution of Nerves to the Vessels of the Connective Tissue in the Hilus of the Pio’s Kidney, and on the Ganglia Found in Connection With These Nerves
Authors: Tyson James
Published: April 2021

Premising that these observations are incomplete, though, I believe, accurate as far as they go, my excuse for bringing them under the notice of the Section at this stage is, that its members may have the opportunity of examining the preparations before they become altered. Having been mounted quite two months, they are still in good keeping, though it is impossible to state how long they will remain thus. The observations, when complete, will also have for their object to determine whether these nerves and ganglia are also distributed to the vessels and tubules in the secreting structure of the kidney, as the labours of Beale appear to have shown; failure to demonstrate this latter point being attributed to want of success in the injecting process—a matter of no inconsiderable difficulty, as the entire organ (that of the young pig) was but an inch in length, and the artery, therefore, exceedingly small. It is hoped that further attempts will accomplish this, though Dr. Beale himself, of whose observations these are a repetition, makes no allusion to having found the nerves Upon the tubules and vessels of the pig’s kidney, but has demonstrated them most satisfactorily in this portion of the kidney of the frog and newt, as will be learned later.
A History of the British Hydroid Zoophytes
Authors: Hincks Thomas
Published: April 2021

The appearance of Mr. Hincks’ long-expected work has supplied a desideratum that must have been felt by nearly all microscopic observers, at any rate when on a visit to the seaside.
On Microscopic Illumination
Authors: Higgins John F.
Published: April 2021

The subject of illumination in the use of the microscope is one upon which much has been written, especially in connection with the merits of various accessories, and yet one the understanding of which is far from general, and, moreover, in reference to which microscopists of acknowledged ability and attainments hold most opposite opinions. In endeavouring to ascertain what are really the facts in the case, and by what rule or rules we should be guided, it becomes necessary, laying aside all previous bias or hitherto conceived opinions, to commence de novo with first principles, and guided by known and absolute laws of light and vision, in conjunction with a careful, complete, and unwearied series of experiments, work out the much desired end.
The Cell Doctrine; its History and Present State
Authors: Tyson James
Published: April 2021

Whilst America is perhaps not doing her share of the work of original observation in the various branches of natural science, we have from time to time abundant proof that her scientific teachers are keeping abreast of the knowledge of the day. Dr. Tyson, who lectures on the microscope and physiology in Philadelphia, has produced in this book an admirable résumé of the history of the various theories and observations on the ultimate structure of organic beings. Whilst giving credit to the earlier observers with the microscope, for their views and observations, he rightly speaks of the researches of Schleiden and Schwann as having introduced a new era into the history of our knowledge of animal and vegetable structure. He passes successively in review the observations of Henle, von Mohl, von Baer, Beale, Bennett, and the views of Huxley. Without going into elaborate detail, he presents the subject in such a way that the student can-not fail to understand the exact bearing of the views of each particular writer, on the subject of what is called “cell-doctrine,” or the “cell-theory.” The author sums up his own views in the following passage.
Notes on Diatomaceæ
Authors: Edwards Arthur Mead
Published: April 2021

I AM one of those who have always strongly advocated the keeping of written and drawn notes by observers of nature. However crude and imperfect the drawings may be, however incomplete the written descriptions, yet, if made conscientiously and with due regard to facts, stating what the observer thinks he sees, they always possess the value of truth, and at the same time serve to place upon record and impress upon the mind many things that would otherwise pass unheeded, and those often of great value. So by following Out such a plan, the mind of the student is drilled in System, the great secret of success in all scientific observations, as well as in other matters. For a long time I have kept a book in which, from day to day, and immediately as observations are made, memoranda are jotted down, often accompanied by sketches, coloured or not, as the subject requires. And on looking back, I frequently find in my older notes the key to some puzzling phenomenon undergoing investigation at a later time. Let not the observer plead the excuse that he cannot draw; I believe that everybody can learn to draw sufficiently well to give a truthful, if not artistic representation of what appears before his eyes. Every one can write well enough to say what he sees when required, and drawing is but a short-hand system of writing.
On a New Sponge, Tethyopsis Columnifer
Authors: Stewart C.
Published: April 2021

For the opportunity of examining and describing this interesting sponge I am indebted to the kindness of my friend Prof. W. H. Flower, of the Royal College of Surgeons.
Notes on Amphidotus cordatos (penn)
Authors: Robertson David
Published: April 2021

In the early part of 1868, on the shores at Cumbrae, my attention was attracted to many holes occurring in the sand. In tracing them to a depth of four or five inches, I found an Amphidotus cordatus under each hole. The diameter of the hole was about equal to that of a crowquill, and often irregular, and rose straight over the long spines surrounding the dorsal impression of the test. By placing one of the animals in a glass jar with two or three inches of sand below and over it, and covering the whole with water, an opportunity was afforded of seeing how the holes were produced and kept open. Long contractile processes, with tentaculated heads— described by Forbes as “long ringed worm-like suckers,” and by John Johannes Müller as “locomotive feet”—were thrust up through the sand, and were seen slowly, and apparently searchingly, wandering over its surface, then grasping particles of the sandy matter in their tentacles, and finally dragging them rapidly down into the hole. As these holes extend from four to five inches into the sand, and I have seen these prehensile tentacles stretch between two and three inches over its surface, the length of these instruments cannot be less than six or seven inches.
On some Freshwater Rhizopoda, New or Little-Known. Fasciculus II. On Amphizonella Vestita (Sp. Nov.), Acanthocystis Spinifera (Greeff) and Plagiophrys Sphærica (Clap, et Lachm)1
Authors: Archer William
Published: April 2021

On a former occasion,2 I brought before the notice of those interested in types of existence so lowly, a series of forms in certain groups of Rhizopoda, at once novel to our freshwaters, as well as some of them possessing in themselves a considerable interest as connecting links, leading on to their more complex and structurally more differentiated marine relatives. Having, since then, continued to bestow some attention to the subject, I venture to propose to bring forward from time to time, as opportunity may offer, such casual jottings, or accounts of any few additional new forms, as good fortune may enable me.
On the Structure and Origin of the Spermatophors, or Sperm-Ropes, of two Species of Tubifex
Authors: Lankester E. Ray
Published: April 2021

In the April number of this Journal last year I called attention to the fact that the so-called opalinoid parasite Pachydermon of M. Claparède,found in the copulatory pouches of certain Oligochœtous Annelids, is in reality a felted mass of spermatozoa, i.e. a spermatophor.
On the Colour of Leaves at Different Seasons of the Year
Authors: Sorby H. C.
Published: April 2021

The number of distinct vegetable colouring matters is so great, and there are so many plants which merit careful examination, that any general conclusions I might now form would probably be considerably modified by further inquiry. This makes me hesitate in giving a decided opinion on many questions connected with my subject; but, at the same time, 1 feel that it is better to run the risk of making some errors than to describe the facts without uniting them by such an amount of theory as may serve to lead to intelligible general principles. I shall, therefore, endeavour to draw such conclusions as the present state of the subject admits, and beg my readers to place no more value on them than I do myself, and to look upon them as provisional, to be modified as our knowledge increases.
Some Remarks on the Nerves of the Cornea of the Rabbit and Frog
Authors: Moseley H. N.
Published: April 2021

Gold preparations of the cornea after they have been in the cabinet for five or six months in a glycerine mount, generally turn dark and very often lose their transparency so thoroughly as to become apparently spoiled. It will be found, however, that from such specimens really beautiful preparations can often be obtained. After this long maceration in glycerine, the cornea can readily be torn into a series of extremely fine layers, so fine, indeed, as in the case of the frog, to be only one cornea-corpuscle thick. As the nerves continually get darker and darker by the further reduction of the gold chloride, these thin layers are extremely instructive with regard to these nerves generally, and especially with regard to their relation to the corpuscles, which it is extremely difficult if not impossible to determine when several layers of corpuscles with the surrounding nerves are in the field at once. Although so much has been written on the subject of the nerves of the cornea, it is hoped that the following remarks and accompanying drawings may not be without interest.
Recent Researches in the DiatomaceÆ.
Authors: O’meara Eugene
Published: April 2021

The second of a series of treatises in course of publication under the direction of Dr. Johannes Hanstein, under the title of ‘Botanische Abhandlungen aus dem Gebiet der Morphologie und Physiologie,’ is eminently calculated to interest such as are engaged in the study of the Diatoms, and promote their knowledge of these interesting and ornamental organisms. These benefits, however, must be confined to those students who are acquainted with German, unless some one undertake to remove the obstruction, and present the treatise in an English dress. ‘
On a Method of Finding the Refractive Index of Glass by Means of the Microscope and White Light
Authors: Royston-Pigott G. W.
Published: April 2021

The following method has occurred to me whilst writing these papers:
A Résumé of Recent Views respecting the Nature of Lichens
Authors: Archer W.
Published: April 2021

A Novel hypothesis respecting the nature of Lichens, which was first propounded by Prof. Schwendener of Basel, and has since to a greater or less extent been adopted by other experienced observers, has for some time past been a subject of controversy between them and botanists of the older school. The “gonidia question,” as it is called, has been discussed in several of the continental journals, and a résumé of some of the papers on both sides will probably possess some interest for English readers. Briefly Schwendener’s view is that the growths which we know as “Lichens” are not independent plants, but ascomycetous fungi, to which certain unicellular or filamentous algæ serve as host-plants, and, therefore, that these latter have hitherto been erroneously regarded, under the name of “gonidia,” as special organs of “Lichens.” Hence each representative of the class is a compound organism made up of two primarily distinct elements.
Review: The Anatomy of the Lymphatic System
Authors: Klein E.
Published: April 2021

This valuable memoir is doubtless one of the most important contributions made to histology within the past year. We are, however, relieved from the necessity of giving a very elaborate notice of the contents, since a portion of the work has already appeared in our journal (‘Quar. Jour. Micro. Sci.,’ 1872, p. 142). ‘
Observations on Spontaneous Movement of Nucleoli
Authors: Kidd P.
Published: April 2021

During an examination of the ciliated epithelial cells from a frog’s mouth Dr. Klein drew my attention to certain cells with special characters to be referred to presently, the nucleoli of which exhibited a crenated appearance; this aroused the suspicion of this being due to amœboid movement. They were therefore subjected to a continuous and careful observation, and it was found that this was actually the case, viz., that these nucleoli perform spontaneous movement. In an ordinary saline solution preparation in which these movements were observed they were, although distinct, yet not very marked, and it was therefore desirable to repeat the experiment under more favorable conditions. A portion of epithelium from the same frog’s mouth was prepared between two thin cover-glasses, in a drop of “humor aqueus” and a thin layer of oil was then painted round the edges of the cover-glasses. The specimen was then placed on a Stricker’s warm-stage, and examined under a No. 10 immersion of Hartnack. The temperature of the warm stage was about 39° C. Several cells were again found similar to those before noticed, viz., cells differing from the other epithelial cells in having no cilia, in their distinct outline and large size, and in the pale and uniformly granular nature of their protoplasm. They possessed a large ovoid vesicular nucleus like the other epithelial cells present, and were provided with a large nucleolus, sometimes with two nucleoli. The larger nucleoli measured 0·002mm., the smaller 0·0015mm. in diameter. As far as morphological characters go these cells were not lymphoid corpuscles, for they were very large, much like columnar epithelial cells, at the same time somewhat irregular in their outline. It should be mentioned that as the frog was suffering from inflammation of the mucous membrane of the mouth, these special cells, from their large size, irregular shape, and the absence of cilia were probably young epithelial cells. On observing one of these cells after a short time a process was developed from its nucleolus, which very soon after was seen to undergo a change not only in length but also in direction. In two or three cases the processes given off from a nucleolus possessed a knob-like projection at their free end, which seemed to vary in distinctness in the course of the observation. After a few days another examination of the epithelial cells from the mouth of the same frog was made under similar conditions, that is to say, the cells were examined between two cover-glasses in a drop of “humor aqiueus,” on a Stricker’s warm stage. Again, amoeboid movements were observed in the nucleoli of these special cells, two or more processes were observed to spring from several nucleoli. In some cases these processes were provided with a small lateral branch, and in one instance such a branch disappeared and a corresponding branch appeared at another point.
On a New Peritrichous Infusorian (Cyclochæta spon-gillæ)
Authors: Jackson WM. Hatchett
Published: April 2021

The Infusorian figured Pl. XII was originally found by my friend Mr. W. H. Poole, of Magdalen College, while engaged in examining a fine fresh-water sponge (Spongilla fluviatilis) taken from the river Cherwell. He was good enough to give me the first specimen as well as another he found subsequently. These two, together with others obtained by myself from the same sponge, form the subjectmatter of the present paper.
The Morphology of the Vertebrate Olfactory Organ
Authors: Marshall A. Milnes
Published: April 2021

Of the two parts into which the present paper is divided, the first deals with the development of the olfactory nerve in certain selected types of vertebrates; the second with the development of the olfactory organ in the same types.
On Certain Points in the Anatomy of Peripatus Capensis
Authors: Balfour F. M.
Published: April 2021

The discovery by Mr. Moseley2 of a tracheal system in Peripatus must be reckoned as one of the most interesting results obtained by the naturalists of the “Challenger.” The discovery clearly proves that the genus Peripatus, which is widely distributed over the globe, is the persisting remnant of what was probably a large group of forms, from which the present tracheate Arthropoda are descended.
On the Use of the Wenham Binocular with High Powers
Authors: Gibbes Heneage
Published: April 2021

A Great many plans have been tried for the purpose of obtaining stereoscopic effect with high powers, and these have all required a special stand or special apparatus entirely removed out of the reach of the ordinary working microscopist, and this led I think to the prevalent idea that the binocular microscope is entirely unsuited for histological or pathological research.
The Origin of the Red Blood-Corpuscles
Authors: Pouchet Professor
Published: April 2021

I have paid a good deal of attention lately (since November, 1877) to the study of the formed elements of the blood and their origin. The fact was, as often happens, that several histologists were pursuing, both in France and elsewhere, the same investigation.
Histological Notes
Authors: Klein E.
Published: April 2021

Dissecting the salivary glands of the guinea-pig I noticed various points in their arrangement and structure which I do not think have been observed by others, and therefore deserve to be described.
On the Micrometric Numeration of the Blood-Corpuscles and the Estimation of their Haemoglobin
Authors: Hart Ernest
Published: April 2021

The micrometric numeration of the blood-corpuscles and the estimation of haemoglobin are operations which, though of comparatively recent introduction, have rapidly passed out of the sphere of laboratory experiment into practical use as exact methods of physiological and clinical investigation. Those who have worked at this subject cannot, however, have proceeded far without discovering that the methods and instruments hitherto in use are inconveniently imperfect and vitiated by numerous sources of error. Some recent improvements by M. Malassez, assistant in the Laboratory of Histology in the Collège de France, appear to me to have done much to remove these disadvantages.
Preliminary Account of the Development of the Lampreys
Authors: Scott W. B.
Published: April 2021

For nearly a year (1879-80) I was occupied in the laboratory of Professor Gegenbaur in working out the development of the Lampreys, the results of which investigations will appear shortly in a more extended form. It seemed, however, desirable to give a preliminary account of the results which have been obtained, in order, as far as possible, to direct the attention of morphologists to the general character of the development of this important and little understood group of Vertebrates. Professor Gegenbaur very kindly placed at my disposal the splendid material which was so laboriously and skilfully collected and prepared by the late Dr. Calberla. This consists of an immense series of preserved embryos and larvæ, and of many thousand prepared sections; and, in addition to these, I have further obtained a fine series of larvæ, for which I am indebted to the friendly offices of Professor Wiedersheim.
The Organ of Jacobson in the Rabbit
Authors: Klein E.
Published: April 2021

In continuation of the research of the organ of Jacobson in mammals, that of the guinea-pig having been described in the January and April numbers, 1881, of this Journal, I now propose to give the results of the minute examination of this organ in the rabbit. The differences in the microscopic anatomy of Jacobson’s organ in these two rodents are very great indeed, much greater than could be anticipated. That of the rabbit in many respects comes very close to the ideal type which Gratiolet 1 draws and describes, and is also similar to the organ in the sheep as described by Balogh 2. The points of resemblance between that of the rabbit and the sheep and the points of dissemblance between that of the rabbit and the guinea-pig will be fully discussed below.
Recent Researches on the Cilio-Flagellata
Authors: Parker T. Jeffery
Published: April 2021

This interesting group of Infusoria has lately received the attention of a Danish zoologist, Mr. R. S. Bergh, who publishes an elaborate monograph on the subject in the last number of Gegenbaur’s ‘Morphologisches Jahrbuch.’1
The Minute Structure of the Lateral and the Central Eyes of Scorpio and of Limulus
Authors: Ray Lankester E. , Bourne A. G.
Published: April 2021

Scope.—In the essay entitled “Limulus an Arachnid,” published in this Journal in 1881, it has been pointed out by one of us (Prof. Lankester) that, amongst other very numerous agreements of structure exhibited by the Scorpions on the one hand and the King Crab on the other, there is a close superficial coincidence in the disposition and the character of the eyes; in both we find a.single pair of simple central eyes, and a lateral or marginal pair of “grouped “or aggregated eyes—the multicorneal lens of the King Crab’s lateral eye corresponding to the numerous (two to seven) small lenses placed in groups laterally on the Scorpion’s head.
The Tongue of Perameles nasuta, with some Suggestions as to the Origin of Taste Bulbs
Authors: Poulton Edward B.
Published: April 2021

I am indebted to the kindness of Professor Moseley for the opportunity of working upon the tongue of this little-known animal. I had expected to meet with interesting details in this investigation, but I hardly ventured to hope for characters with so important a bearing on general development as, it appears to me, are to be found in this organ, especially when such suggestive structures are combined with so much highly specialised peculiarity.
On the Structure and Development of Loxosoma
Authors: Harmer Sidney F.
Published: April 2021

The investigations which form the subject of the present paper were carried on during an occupation of the Cambridge University Table at Naples from. January to July, 1884. An account of my main results was communicated to the Montreal meeting of the British Association in September, 1884, and a short abstract will appear in the forthcoming report.
On Green Oysters
Authors: Lankester E. Ray
Published: April 2021

The investigation of the nature of the colouring matters which occur in different organisms, has always appeared to me one of especial importance, leading us, on the one hand, into a remarkable region of physiological phenomena, and on the other hand, helping us to trace to their true physical causes some of the most beautiful and at the same time most puzzling of organic developments. The chemical and functional characteristics of pigment-compounds are daily becoming better understood, and at the same time we are obtaining some notion of the way in which nature has here and there taken hold of the accidental non-significant property of colour in a by-product of the organism’s chemical factory, and has assigned to the pigment a high position of importance as an ornament, a protective, or a lure.
ERRATA
Authors: Fowler G. Herbert
Published: April 2021

On page 444, fifth line from bottom, for “p. 29” read “p. 458.”
On the Anatomy of Mussa and Euphyllia, and the Morphology of the Madreporarian Skeleton
Authors: Bourne G. C.
Published: April 2021

The following paper contains a description of the anatomy of two genera of Madreporaria aporosa, Mussa and Euphyllia, concluding with a general account of the morphology of the Madreporarian skeleton in the light of the most recent researches on the group. My thanks are due to Professor Moseley, who kindly gave me the specimens of Euphyllia with which I worked, and assisted me with his advice; to Mr. W. Hatchett Jackson, whom I frequently consulted on the more general morphological questions contained in the latter part of this paper; and to Dr. G. H. Fowler, who kindly lent me for reference proofs of his latest paper on the Madreporaria before it had appeared in public print.
Contributions to the Knowledge of Amphioxus lanceolatus, Yarrell
Authors: Lankester E. Ray
Published: April 2021

It is now fourteen years since I published in the ‘Quarterly Journal of Microsc. Science’ (vol. xv) some notes on the structure of Amphioxus. I have delayed publishing until the present date fuller illustrations of the facts then recorded, but have made use of my material in annually recurring lectures at University College.
Studies in the Embryology of the Echinoderms
Authors: Bury H.
Published: April 2021

In the following pages I propose to give a comparative account of the structure and development of certain organs in young Echinoderm larvæ. I am not here concerned with the earliest stages (gastrula, &c.), nor with those later ones in which the pentamerous symmetry of the adult is already assumed, but only with that bilaterally symmetrical stage which is more or less clearly represented in all Echinoderm larvæ, and to which Semon (28) has given the convenient name “Dipleurula.”
The Nephridium of Lumbricus and its Bloodsupply; With Remarks on the Nephridia in other Chætopoda
Authors: Benham W. Blaxland
Published: April 2021

The nephridium of the common earthworm has recently been the subject of a contribution by Dr. Goehlich (20), in which he remarks on various statements made by Gegenbaur in his classical paper on the subject, published in 1853 (19), in which he corrected the then prevailing view that the segmentally arranged tubes were respiratory, and suggested their excretory function.