bluuebunny/crossref_metadata_2025 huggingface dataset:
Microtubule distribution and function in early Pelvetia development
Authors: Kropf Darryl L. , Maddock Anna , Gard David L.
Published: April 2021

We have used immunofluorescence microscopy to examine the distribution of microtubules (Mts) during the first two cell cycles in embryos of the brown alga, Pelvetia. Prior to germination of the zygote at 12 h post-fertilization, Mts radiated from the circumnuclear region into the peripheral cytoplasm. After rhizoid emergence, Mts resolved into two perinuclear microtubule organizing centers (MTOCs). The axis defined by the pair of MTOCs was oriented transverse to the growth axis, with Mts extending from each MTOC into the rhizoid. The axis defined by the MTOCs then reoriented by 90 degrees, and aligned with the growth axis. The first mitotic spindle formed between these MTOCs. The division plane bisected the spindle, giving rise to rhizoid and thallus cells with distinct developmental potentials. During the second cell cycle, the axis defined by MTOCs in the rhizoid cell again reoriented from an orthogonal to an axial alignment with respect to the growth axis. MTOC reorientation did not occur in the thallus cell, and the division planes in the rhizoid and thallus cells were orthogonal to one another.

Zygotes treated with amiprophos methyl (APM) or taxol established an axis and initiated rhizoid outgrowth. However, treated zygotes ceased growing soon after germination and failed to divide. Cytochalasin D, which prevents establishment of the developmental axis, interfered with the proper orientation of the spindle. From these results we conclude that(1)Mts are not required for establishment of the rhizoid-thallus axis or rhizoid germination;(2)an F-actin-dependent process, probably establishment of a developmental axis, is required for rotation of the axis defined by MTOCs; and (3) the alignment of perinuclear MTOCs dictates the orientation of spindle and subsequent division planes, and thereby controls cell lineage.
Selective digestion of nuclear envelopes from Xenopus oocyte germinal vesicles: possible structural role for the nuclear lamina
Authors: Whytock Sue , Moir Robert D. , Stewart Murray
Published: April 2021

We have used enzymic digestion as a structural probe to investigate components of the nuclear envelope of germinal vesicles from Xenopus oocytes. Previous studies have shown that these envelopes are composed of a double membrane in which nuclear pore complexes are embedded. The nuclear pore complexes are linked to a fibrous lamina that underlies the nucleoplasmic face of the envelope. The pores are also linked by pore-connecting fibrils that attach near their cytoplasmic face. Xenopus oocyte nuclear envelopes were remarkably resistant to extraction with salt solutions and, even after treatment with 1M NaCl or 3 M MgCl2, pores, lamina and pore-connecting fibrils remained intact. However, mild proteolysis with trypsin selectively removed the lamina fibres from Triton-extracted nuclear envelopes to leave only the pore complexes and connecting fibrils. This observation confirmed that the pore connecting fibrils were different from the lamina fibres and were probably constructed from different proteins. Trypsin digestion followed by Triton treatment resulted in the complete disintegration of the nuclear envelope, providing direct evidence for a structural role for the lamina in maintaining envelope integrity. Digestion with ribonuclease did not produce any marked change in the structure of Triton-extracted nuclear envelopes, indicating that probably neither the pore-connecting fibrils nor the cytoplasmic granules on the pore complexes contained a substantial proportion of RNA that was vital for their structural integrity.
p34cdc2 homologue level, cell division, phytohormone responsiveness and cell differentiation in wheat leaves
Authors: John P. C. L. , Sek F. J. , Carmichael J. P. , Mccurdy D. W.
Published: April 2021

Formation of a plant involves generation of new cells by the division cycle and development in these of specialised structure and metabolism. Specialisation is accompanied by a decreasing capacity for division, which declines with particular rapidity in cells of monocotyledonous plants such as the cereals. Here we report that in wheat leaves a homologue of the cell cycle control protein p34cdca participates in the control of these developmental programmes. Accumulation of p34cdc2 to a maximum level in dividing cells and the cessation of its accumulation during subsequent cell growth and expansion indicate that it contributes specifically to division. There is a decline in p34cdc2 level as cell differentiation pro ceeds, in close parallel with the previously established decline of cell division in response to auxin hormones. A basal level of p34cdc2 in fully differentiated cells that is one-sixteenth of that in dividing cells correlates with their loss of capacity to divide. We conclude that p34cdc2 level is controlled in diverse multicellular eukaryotes and suggest that it is an important element in the switch from cell division to differentiation.
Development of desmosomal adhesion between MDCK cells following calcium switching
Authors: Mattey D. L. , Burdge G. , Garrod D. R.
Published: April 2021

The development or maturation of intercellular adhesions following their initiation has received very little attention even though this is an area of significance for a variety of in vivo processes. Using Ca2+-induced desmosome formation in MDCK cells as a study system it is shown that, following its initiation, desmosome formation continues for many hours. Following Ca2+ switching the major desmosomal glycoproteins, dg2/3a,b (desmocollins), accumulate progressively at the cell surface. Accumulation is first detectable within 45 min, but continues linearly for ∼16h, reaching a plateau at 24–32 h at 15 times the amount present in low-Ca2+ medium (LCM). Desmosomes do not increase in size during this time, but appear to become more numerous. These results suggest that cells progressively increase their desmosome-mediated adhesion over this period of time.

Cycloheximide treatment shows that ∼93% of the total dg2/3a,b accumulation is dependent upon protein synthesis after Ca2+ switching and only ∼7% on assembly of pre-synthesised material. Thus, although triggering of desmosome formation is rapid, protein synthesis makes a major contribution to the gradual development of desmosomal adhesion in these cells.

The initial assembly phase itself can be inhibited by treating cells in LCM with chloroquine, which reduces the cell surface concentration of dg2/3a,b by 40–50%. However, slow dg2/3a,b accumulation does take place in chloroquine and, if protein synthesis is permitted, desmosome formation occurs.

It is suggested that when cell contacts are formed in vivo, maximisation of intercellular adhesiveness may take many hours and is dependent on the synthesis and accumulation of adhesive components.
Polarization of pseudopodial activities: cytoskeletal mechanisms
Authors: Vasiliev J. M.
Published: April 2021

The reorganization of the cytoskeleton resulting in a stabilized polarization in cells of two types, Dictyo-stelium amoebae and cultured mammalian fibroblasts, is compared. It is suggested that there are two levels of reorganization: basal level reorganization of actin-myosin cortex and a higher level of reorganization of microtubules and intermediate filaments.
Non-neuronal 210×103Mr microtubule-associated protein (MAP4) contains a domain homologous to the microtubule-binding domains of neuronal MAP2 and tau
Authors: Chapin Steven J. , Chloë Bulinski Jeannette
Published: April 2021

A polyclonal antiserum raised against a HeLa cell microtubule-associated protein of Mr210000 (210 kD MAP or MAP4), an abundant non-neuronal MAP, was used to isolate cDNA clones encoding MAP4 from a human fetal brain λ gtll cDNA expression library. The largest of these clones, pMAP4.245, contains an insert of 4.1 kb and encodes a 245 kD β-galactosidase fusion protein. Evidence that pMAP4.245 encodes MAP4 sequences includes immunoabsorption of MAP4 antibodies with the pMAP4.245 fusion protein, as well as identity of protein sequences obtained from HeLa 210 kD MAP4 with amino acid sequences encoded by pMAP4.245. The MAP4.245 cDNA hybridizes to several large (∼6–9 kb) transcripts on Northern blots of HeLa cell RNA. DNA sequencing of overlapping MAP4 cDNA clones revealed a long open reading frame containing a C-terminal region with three imperfect 18-amino acid repeats; this region is homologous to a motif present in the microtubule (MT)-binding domain of two prominent neuronal MAPs, MAP2 and tau. The pMAP4.245 sequence also encoded a series of unrelated repeats, located in the MAP’s projection domain, N-terminal to the MT-binding domain. MAP4.245 fusion proteins bound to MTs in vitro, while fusion proteins that contained only the projection domain repeats failed to bind specifically to MTs. Thus, the major human non-neuronal MAP resembles two neuronal MAPs in its MT-binding domain, while most of the molecule has sequences, and presumably functions, distinct from those of the neuronal MAPs.
Murine cDNAs coding for the centrosomal antigen centrosomin A*
Authors: Joswig Gaby , Petzelt Christian , Werner Dieter
Published: April 2021

Screening of an induced Ehrlich ascites cell-derived λgtll cDNA library with an antibody (GP1), immunoreacting specifically with centrosomal antigen(s) of interphase and mitotic cells of different species, released a partial cDNA clone (λP10A) encoding the carboxy-terminal section of a centrosome-specific antigen. This specificity of the clone λP10 A could be verified by 7acZ-directed antigen expression from Escherichia coli Y1089 lysogenized with the recombinant phage λP10 A and subsequent production of centrosome-specific antibodies by means of the recombinant antigen. Using the λP10A insert as a probe, two types of cDNA clones were identified in a λgt10 cDNA library by plaque-hybridization. The inserts of PN1 type clones were 1.2 kb (kilobases) and those of PN5 type clones were 2.2 kb in length. The DNA sequence of a PN1 type clone revealed its fulllength cDNA nature. The open reading frame of PN1 encodes a rather hydrophilic and highly charged 34.5 × 103 Mr polypeptide comprising short but apparently significant strings of 100% sequence identity with the major nuclear lamina polypeptides lamins A/C and lamin B. Restriction enzyme mapping of PN1 and PN5 inserts, cross-hybridization experiments and comparison of overlapping DNA sequences indicate that the 1.2 kb and 2.2 kb cDNAs code for the same 34.5×103Mr polypeptide, termed centrosomin A. Western blots of Ehrlich ascites cell proteins show a second, larger GP1 antigen (centrosomin B) whose cDNA has not been cloned. It remains to be investigated whether centrosomin B is encoded by a second mRNA or whether it reflects an oligomeric or a postranslationally modified form of centrosomin A.
Expression and compartmentalization of integral plasma membrane proteins by hepatocytes and their progenitors in the rat pancreas
Authors: Bartles James R. , Rao M. Sambasiva , Zhang Liqin , Fayos Barbara E. , Nehme Cheryl L. , Reddy Janardan K.
Published: April 2021

A combination of Western blotting, Northern blotting and immunofluorescence was used to examine the expression and compartmentalization of plasma membrane proteins by those hepatocyte-like cells that arise in the pancreases of rats subjected to sequential dietary copper depletion and repletion. The pancreatic hepatocytes were found to: (1) express several integral membrane proteins known to be concentrated within the apical, lateral or basolat-eral domains of the plasma membranes of hepatocytes in liver; and (2) compartmentalize the membrane proteins to equivalent plasma membrane domains, despite the organization of these cells into clusters instead of highly vascularized plates. The apical plasma membrane proteins dipeptidylpepti-dase IV and HA 4 were found to line bile canaliculus-like openings between adjacent pancreatic hepato-cytes; these openings were shown to be continuous with the pancreatic exocrine duct by India ink infusion. In contrast, the basolateral plasma membrane protein rat hepatic lectin-1 and lateral plasma membrane protein HA 321 were detected elsewhere about the surfaces of the pancreatic hepatocytes: by analogy to their respective localizations on hepatocytes in liver, rat hepatic lectin-1 was concentrated on those surfaces exposed to the pancreatic matrix at the periphery of the hepatocyte clusters (the basal surface equivalent), whereas HA 321 was concentrated on those surfaces exposed to adjacent hepatocytes within the clusters. The hepatocyte plasma membrane proteins were found to be expressed in the pancreas at different times during the copper depletion/repletion protocol: for example, rat hepatic lectin-1 and the bulk of the HA 4 were expressed relatively late in the protocol, only after large numbers of pancreatic hepatocytes had appeared; whereas dipeptidylpeptidase IV was induced > 10-fold early in the protocol and proved to be an apical-specific marker for those ductular epithelial cells that are believed to be the progenitors of the pancreatic hepatocytes.
Evidence that estramustine binds MAP-1A to inhibit type IV collagenase secretion
Authors: Stearns Mark E. , Wang Min , Sousa Odete
Published: April 2021

Estramustine is a novel anti-microtubule drug shown to bind MAP-1 and MAP-2 (microtubule-associated proteins) in vitro. In this paper we have shown that estramustine specifically binds MAP-1A in Du 145a cells, resulting in disruption of MAP-1A microtubules and inhibition of type IV collagenase secretion. Immunofluorescence studies revealed that at 30μM levels estramustine blocked type IV collagenase secretion by partial disruption of the MAP-1A microtubule networks. Immunoprecipitation studies with polyclonal antibodies provided quantitative evidence that 30–60 μM estramustine blocked secretion of a 105 ×103Mr type IV collagenase. Pulse labeling experiments confirmed that the effect was not a result of inhibition of either protein synthesis or altered rates of type IV collagenase turnover. Finally, drug uptake studies with [3H]estramustine, scintillation counting and fluorography demonstrated that the principal target of the drug was MAP-1A. For the first time we have shown that the drug blocks secretion by binding MAP-1A and causing incomplete disruption of the microtubule networks.
Isolation and characterisation of clones from the Caco-2 cell line displaying increased taurocholic acid transport
Authors: Woodcock Sian , Williamson Ian , Hassan Ian , Mackay Martin
Published: April 2021

The Caco-2 cell line has been cloned by the limiting dilution technique. Clones and reclones have been tested for growth characteristics, transepithelial electrical resistance, ability to transport taurocholic acid specifically and morphological homogeneity. Although clones have similar growth patterns to the parental population they display a variety of electrophysiological, biochemical and morphological characteristics. One clone, clone 40, has been characterised in detail and shown to transport significantly higher amounts of taurocholic acid. Moreover, this clone displays morphological homogeneity and is stable with respect to this parameter over an extended time period.
Influence of basement membrane molecules on directional migration of human breast cell lines in vitro
Authors: Coopman P. J. , Bracke M. E. , Lissitzky J. C. , Bruyne G. K. De , Roy F. M. Van , Foidart J. M. , Mareel* M. M.
Published: April 2021

Spheroidal cell aggregates were prepared from four tumorigenic human breast cell lines (HBL-100 and three MCF-7 variants). Cells from these aggregates were allowed to migrate towards lanes of basement membrane components coated on a glass substratum. Matrigel™ (reconstituted basement membrane) lanes permanently arrested the migration of one MCF-7 cell line, while migration of the others was permitted. Amongst several purified basement membrane constituents only laminin, not collagen type IV or fibronectin, was found to cause the same arrest of migration. Within the laminin molecule only the pepsin Pl, not the elastase E8 fragment, efficiently arrested migration of that cell line. Although migration was inhibited by these components, timelapse video recordings revealed that arrested cells still proliferated and actively ruffled on top of the coatings.

These data suggest that, amongst several basement membrane components, laminin can function as a stop signal for cell migration. Within laminin, this activity seems to be mainly associated with the Pl fragment We conclude that laminin is the major determinant of the barrier-function of the basement membrane, to which some cell types have become insensitive.
Embryonic cell invasiveness: an in vitro study of chick gastrulation
Authors: Sanders E. J.
Published: April 2021

An investigation has been made into some of the possible mechanisms underlying the invasionary activity of gastrulating cells at the primitive streak of the early chick embryo. At gastrulation, epithelial cells in the upper epiblast layer of the embryo undergo a transformation into fibroblastic mesenchyme cells by passage through the primitive streak and penetration of a basement membrane. The resulting cells constitute the first embryonic mesoderm, which then invades the underlying tissue space. This phenomenon has been studied in vitro using the invasion of Matrigel, a reconstituted basement membrane, as a model. Mesoderm cells explanted into this matrix were subjected to treatments aimed at perturbing a number of putative mechanisms for cellular invasion. Application of inhibitors of glycosylation (tunicamycin) and oligosaccharide processing (castanospermine, deoxyman- nojirimycin, swainsonine) resulted in various degrees of inhibition of invasion. By contrast, cell binding fragments from fibronectin and laminin did not impede invasion, and neither did a panel of enzyme inhibitors, including serine protease and metalloprotease inhibitors. It is concluded that the primary determinant of the invasionary behaviour of these cells at gastrulation is a change in cell surface carbohydrate determinants, and that there is no evidence for the participation of localized enzymic activity. The medial disruption of the basement membrane seen at the primitive streak is therefore most likely to be due to local failure of synthesis, rather than local degradation.
Interpreting nucleolar structure: where are the transcribing genes?
Authors: Jordan E. Gwyn
Published: April 2021

The nucleolus, the site of ribosomal RNA synthesis, provides us with one of the best opportunities for unravelling the relationships between transcription and the spatial organization of chromatin. Some of the best visualizations of the transcription process have come from nucleolar spread preparations (Miller, 1981) but this procedure introduces major structural reorganizations that deny us a molecular interpretation of the intact nucleolus.
Evidence that cyclic GMP may regulate the association of myosin II heavy chain with the cytoskeleton by inhibiting its phosphorylation
Authors: Liu Gang , Newell Peter C.
Published: April 2021

Previous studies have implicated cyclic GMP in the regulation of myosin II heavy chain (MHC) association with the cytoskeleton in Dictyostelium discoideum. Here we provide evidence that cyclic GMP may regulate MHC association with the cytoskeleton through MHC phosphorylation. Comparative data are presented of MHC phosphorylation in the wildtype strain NC4, the parental strain XP55 and streamer mutants NP368 and NP377.

Using an anti-MHC monoclonal antibody to immunoprecipitate MHC from [32P]phosphate-labelled developing cells, we found that cyclic AMP stimulation of the wild-type strain NC4 and parental strain XP55 induced MHC phosphorylation in vivo. A peak of phosphorylation was observed at 30–40 s, followed by a gradual decrease to basal level at 160 s. In contrast, in both of the streamer mutants NP368 and NP377 (which have prolonged cyclic GMP accumulation and prolonged MHC association with the cytoskeleton), the phosphorylation of MHC was delayed and did not form a peak until 60–80s after cyclic AMP stimulation. We also found that cyto-skeletal MHC showed only minor phosphorylation, the majority of the phosphorylated MHC being found in the cytosol.

We present a model to account for these results in which cyclic GMP regulates MHC association with the cytoskeleton by regulating the phosphorylation/ dephosphorylation cycle of MHC in these cells.
Overproduction and secretion of β2-microglobulin by a rat thymic epithelial cell line that expresses MHC class I heavy chain
Authors: Dargemont Catherine , Dunon Dominique , Salamero Jean , Deugnter Marie-Ange , Davoust Jean , Thiery Jean Paul
Published: April 2021

Major histocompatibility complex (MHC) class I antigens are constituted of dimers consisting of a peripheral light chain, β2-microglobulin (β2m) and a transmembrane heavy chain whose cell surface expression depends on its assembly with β2m. In contrast, soluble β2m can be secreted in the absence of heavy chain expression. The presence of β2m in medium conditioned by a rat thymic epithelial cell line, IT45-R1 (IT45) prompted us to investigate whether β2m could be secreted by cells that express MHC class I antigens. IT45 cells produce three to five times more β2m in the culture supernatant than another rat thymic epithelial cell line, IT26-R21 (IT26). The IT45 cell line exported β2m through a constitutive pathway of secretion, as indicated by the kinetics of production and localization of intracellular β2m. Although cells from the IT45 cell line expressed a much higher amount of β2m as compared to IT26 and NBT II cells (a rat bladder epithelial cell line), all three of these cell lines expressed the same amount of membrane and intracellular MHC class I heavy chain. These data are thus consistent with a constitutive secretion of 02m dependent upon an overexpression of MHC class I light chain as compared to the heavy chain. The amount of β2m mRNA and the ratio of β2m versus MHC class I heavy chain transcripts were higher in IT45 than in IT26 cells, indicating that overexpression of 02m in IT45 cells could be due to an enhanced level of β2m mRNA. These results demonstrate that β2m can be oversynthezised and consequently secreted by cells that express MHC class I heavy chains. It may thus suggest that β2m could be secreted differentialy at specific body sites, which remain to be determined.
Effects of 6-dimethylaminopurine on microtubules and putative intermediate filaments in sea urchin embryos
Authors: Dufresne Louise , Néant Isabelle , St-Pierre Johanne , Dubé FrançOis , Guerrier Pierre
Published: April 2021

The effects of 6-dimethylaminopurine (6-DMAP) (a putative phosphorylation inhibitor) on the state of assembly of microtubules and intermediate filaments have been studied during the first cell cycle of the sea urchin Strongylocentrotus droebachiensis. Changes in the spatial organization of cytoskeletal structures were studied by indirect immunofluorescence with anti-tubulin and anti-IFa antibodies. The rates and patterns of protein phosphorylation in control and treated eggs were also investigated.

The transfer of fertilized eggs to 600 pM 6-DMAP within 4 min following insemination inhibits pronuclear migration and syngamy. This also prevents male pronuclear decondensation, while chromatin condensation and nuclear envelope breakdown do not occur in the female pronucleus. Immunolabeling with anti-tubulin antibodies reveals the presence of cortical microtubules as early as 15 min after fertilization in both control and treated eggs. However, no sperm astral microtubules could be detected in the treated eggs. At later stages, from syngamy (40 min) up to nuclear envelope breakdown (90 min), 6-DMAP affects neither cortical microtubule organization nor the state of chromatin condensation but it precludes nuclear envelope breakdown and entry into mitosis. Treatment of the fertilized eggs after nuclear envelope breakdown induces permanent chromosome decondensation and premature disappearance of the mitotic apparatus. This last event involves disruption of the spatial organization of both microtubules and putative intermediate filaments.

Quantitative measurements of protein phosphorylation show that 6-DMAP efficiently and reversibly inhibits 32P incorporation into proteins. Qualitative analysis of the autoradiograms of 32P-labeled proteins separated by SDS-PAGE reveals that a major protein band, migrating with an apparent molecular weight of 31 × 103Mr, is specifically dephosphorylated in eggs treated with 6-DMAP.

This study suggests that protein phosphorylation is required for sperm aster microtubule growth and migration, but not for cortical microtubule polymerization. It also strengthens the hypothesis that, in sea urchin eggs, putative intermediate filaments are tightly associated with spindle microtubules. Finally, it confirms that inhibiting protein phosphorylation before nuclear envelope breakdown reversibly prevents the entry into mitosis.
The response of endothelial cells to TGFβ-1 is dependent upon cell shape, proliferative state and the nature of the substratum
Authors: Sutton A. B. , Canfield A. E. , Schor S. L. , Grant M. E. , Schor A. M.
Published: April 2021

Endothelial cells plated on two-dimensional (2-D) substrata proliferate until they form a tightly apposed confluent monolayer of quiescent cells that display a typical ‘cobblestone’ morphology. When added to proliferating cultures TGFβ-1 (transforming growth factor β-l) inhibited cell growth and caused marked morphological changes, with the cells becoming enlarged and ragged. These effects were dose-dependent and reversible. TGFβ-1 also reduced the cloning efficiency and colony size of these cells, indicating that TGFβ-1 is cytotoxic and cytostatic for endothelial cells. By contrast, TGFβ-1 added to quiescent cobblestone cultures did not affect cell morphology or cell numbers. In the presence of 20% serum, the level of total protein synthesis per cell was significantly increased by TGFβ-1 in a dose-dependent manner when the cells were cultured on a 2-D substratum, regardless of whether the cells were proliferating or cobblestone quiescent. The level of plasminogen activator inhibitor type 1 was specifically increased in these cultures, as demonstrated by reverse fibrin zymography and immunoprecipitation. Endothelial cells embedded within a 3-D collagen gel display an elongated ‘sprouting’ morphology. Such cells self-associate to form three-dimensional cellular networks within the gel, but do not proliferate. The addition of TGFβ-1 to these quiescent sprouting cells initially induced rounding-up without altering protein synthesis, and cell death occurred later. The effects of TGFβ-1 on sprouting endothelial cells were also examined using two culture systems where both the cobblestone and the sprouting phenotypes were present. TGFβ-1 reduced the number of cells present and the extent of migration of sprouting cells embedded within a type I collagen gel, but had no effect upon sprouting cells embedded within a complex endothelial-produced extracellular matrix. Large vessel (aortic) and microvessel (retinal) endothelial cells responded in a similar way to TGFβ-1; the only difference being that an increased synthesis of PAI-1 was not observed with sub-confluent BREC cultures. Our results suggest that the effects of TGFβ-1 upon endothelial cells depend on the shape (cobblestone or sprouting), on the proliferative state of the cells, and on the nature of the matrix surrounding the cells. The response of these cells to TGFβ-1 in vivo may be similarly modulated during angiogenesis by changes in the cell phenotype and the composition of the surrounding matrix.
On the Photographic Delineation of Microscopic Objects by Artificial Illumination
Authors: Shadbolt George
Published: April 2021

The application of Photography to the purpose of delineating microscopic forms I have for some years entertained as a favourite project; but some practical difficulties of mani-lation deterred me from putting it to the test until quite recently, when a sufficient stimulus was applied in the beautiful specimens both on paper and glass exhibited in the month of October last, at the Microscopical Society of London, by Mr. Joseph Delves, of Tonbridge Wells. Of the excellent promise for a highly valuable adjunct to microscopic science, the proofs in the present Number of the Journal will afford your readers an opportunity of judging.
Excess of the Colourless Corpuscles of the Blood (Leucoeythemia) occurring in Cases of Goitre
Authors: Holland Thomas S.
Published: April 2021

The impulse which the researches of Professors Bennett and Virchow have given to the study of the histological alterations in the Blood will be, I presume, sufficient excuse for the publication of these observations ; and by confining myself to a simple narration of facts I hope to secure the attention of those who live in districts in which Goître is of frequent occurrence, and perhaps induce them to make, in all such cases, a microscopical examination of the blood.
On the Practical Application of Photography to the Illustration of Works on Microscopy, Natural History, Anatomy, &c
Authors: Highley jun Samuel
Published: April 2021

Many scientific phenomena, when first discovered, either from their remarkability or beauty, have excited much interest in the popular mind, but have only been regarded by it as pleasing toys, till in the course of time their practical value has been discovered, and they have been arranged thereafter in the list of applied sciences.
On the Psorospekmia and Gregarinæ
Authors: Leydig D. F.
Published: April 2021

The Psorospermia are microscopical corpuscles of a peculiar kind, which may be generally characterized, in the full-grown condition, as rounded organisms, having a sharply-defined outline, with or without a tail-like appendage. They are flattened and lenticular in figure, and one pole is usually acuminute; and towards this pole several internal vesicles converge in a symmetrical manner. These creatures were discovered by Joh. Miiller in 1841 (Mull. Arch., 1841, p. 477). He found in a young Pike minute round cysts in the cellular tissue of the muscles of the eye, in the substance of the sclerotica, and between this and the choroid coat. The contents of the cysts was a whitish substance, which, when examined microscopically, was found to consist of peculiar elements—the “ Psorospermia.” [A detailed notice of these observations is given in the ‘ Microscop. Journal,’ vol. ii. p. 123, and in the ‘ Brit, and Foreign Med. Rev.,’ January, 1842.] In the following year the same observer (Müller’s Arch., 1842, p. 193) discovered parasitic corpuscles in the swimming bladder of a Gadus callarius, which, although specifically distinct from the Psorospermia, approached very near the latter in their organization. They resembled in general a smooth ventricose Navicula, and consisted of two elongated cases applied to each other at the cavity, and with an elliptical outline and convex outer surface. They were in part free, in part enclosed in masses within a tunic. Similar cysts, containing “ Psorospermia,” have been found by Leydig in several species of fish, and in all parts nearly of their bodies, and even in the blood contained in the heart (p. 223), and in the peritoneal cavity.
Experiments on the Transmission of Intestinal Worms
Authors: Herbst M.
Published: April 2021

The author’s experiments appear to have been directed only to the Trichina spiralis, or allied species. He recognizes three species of this genus. The first, corresponding in all respects with that discovered in the human body by Hilton, Owen, and Bischoff, was met with in the voluntary muscles of a large old cat. Shortly afterwards he met with a second species in the mesentery of Strix passerina. It occurred in the substance of the muscles, and also in the mesentery, in which situation the worm occupied yellowish tubercles about the size of a pin’s head. This Trichina is distinguished not only by a body double the size of that of the other, but principally by the abnormal form of its extremities. The enlarged head terminates in a short conical point, the surface of which is verrucose, and the attenuated tail seems to be furnished with two papillary protuberances at the extremity, as well as with an infundibuliform opening. The third species was met with by the author in 1848, in the muscles of a full-grown dog. The cysts were very small, scarcely visible to the naked eye. The vermiculi enclosed in them were much smaller, but in other respects resembled those of the first species, from which, consequently, it may be considered doubtful whether they are really specifically distinct.
On the Structure of the Cutaneous Follicles of the Toad, with some Experiments and Observations upon the Nature and alleged Venomous Properties of their Secretion
Authors: Rainey George
Published: April 2021

From time immemorial a venomous quality has been attributed to one or other of the secretions of the toad. Scarcely any one who has spent much time in the provinces of this, and other countries, has failed to hear of instances of supposed poisoning by this reptile: these accounts, however, have always been so vague and imperfectly attested, as to obtain credit only among the uninformed and superstitious classes of the people, so that by enlightened persons the belief in the venomous powers of the Toad has been regarded only as a vulgar prejudice. Such were the doubts and opinions entertained upon this subject as late as 1851, when they were said to be set at rest, and the poisonous nature of the cutaneous secretion of the toad demonstrated by two French philosophers, MM. Gratiolet and S. Cloez, who, by inoculating various animals with the secretion in question, produced, according to the account given of these experiments, most decided results, and, in some instances, almost immediate death.
Observations on the Circulation of the Sap in the Leaf Cells of Anacharis Alsinastrum
Authors: Wenham F. H.
Published: April 2021

There is no known plant in which the sap-rotation has been discovered that displays the phenomena of the circulation more distinctly, or in such variety of detail, as the newly imported water-weed, Anacharis Alsinastrum. Having observed some peculiar features in this, which I have not discovered in the circulating sap of any other plant, I venture to announce them. I must, however, premise that I have not made a special study of this department of vegetable physiology, and may therefore be excused from drawing any conclusions, or for showing a defective acquaintance with technicalities ;—I have simply to relate what I have seen.
On the Cellulose (in Animals) Question
Authors: Virchow R.
Published: April 2021

Since my former communications respecting the substance met with in the human body resembling vegetable cellulose, I have taken much pains to ascertain more precisely its nature. In now recurring to the subject, it is not that I have been altogether successful in the inquiry, but rather because I perceive that it is becoming more and more involved in confusion. There are some even who, whether from superficiality or for other reasons, appear to regard what I have said,—as I believe with sufficient distinctness—as unsaid, and have busied themselves in associating with the amyloid bodies described by me, bodies of all kinds, only morphologically analogous with them. The reaction of iodine and sulphuric acid having once been established, nothing can be described as a corpus amylaceum which does not exhibit this reaction. At most can such bodies be termed corpora amylacea spuria.
On the Action of a Concentrated Solution of Urea upon the Blood-Cells
Authors: Kölliker A.
Published: April 2021

In the prosecution of a series of researches, respecting the influence of various reagents upon the spermatic filaments, I have almost always employed the blood-cells as a test of the degree of concentration of the fluids experimented with. I was thus led to observe, in the Frog, a remarkable change produced in the blood-cells by a concentrated solution of urea (30 per cent.). The blood-cells gradually acquired an irregular, jagged outline, and were rapidly transformed into the most beautiful stellate cells, usually having 3—6 tolerably long and somewhat clavate processes, so as to be brought to resemble very closely the irregularly-stellate pigment-cells of the lamina fusca of the sclerotic. This elegant form, however, was not long retained ; for the processes now began speedily to become melted down, sometimes disappearing by a gradual process of fusion commencing at the border of the cell, and occasionally in detaching larger or smaller droplets, which immediately became pale and disappeared. Thus, at last, the nuclear part of the cell only remained as a minute, round, dark-red, brilliant globule, which, ultimately, also lost its colour and disappeared up to the nucleus without leaving a trace.
Notice respecting the Occurrence of Lymph-Corpuscles in the commencements of the Lymphatic Vessels
Authors: Kölliker A.
Published: April 2021

The recent researches of Virchow on the one hand, and of Brücke, Donders, and myself on the other., have shown that the lymphatic glands are the principal seat of origin of the cellæform elements of the chyle. The further question arises, as to whether lymph-cells are formed in other situations besides those organs, and particularly, whether the independent formation of such cells, in the commencement of the-lacteals, which has recently been almost universally assumed, be really deducible from well-ascertained facts. This question is of the greater interest, that the formation of lymph-cells in the commencement of lymphatics has hitherto been regarded as one of the most certain instances of the formation of cells around isolated nuclei contained in a fluid, whilst the more recent results of histological inquiries have tended more and more to limit the occurrence of a free cell-formation independent of pre-existing cells. Consideration of the foregoing facts, would certainly, at first sight, appear to render the question now in discussion superfluous, inasmuch as it has long been proved that the lacteal s of the small intestine, even at their commencement between the intestine and the mesenteric glands, contain lymph-corpuscles ; but here the possibility arises, that the cells may be derived from the Peyerian and solitary follicles, whose connexion with the lacteals is asserted by Brücke, and which on this account have been regarded as a kind of lymphatic glands. In this state of things, it is above all necessary to investigate the conditions under which, and the situations in which, the lymphatics contain cellæform elements previously to their reaching the lymphatic glands, and where not; an investigation which, when carried out sufficiently, is more difficult than it appears at first sight. Although I have had neither opportunity nor leisure of instituting detailed researches on this subject, still I am in a condition to communicate some facts, which may serve as an introduction to further inquiries.
On the Influence of Caustic Alkalies upon the Motions of the Spermatic Filaments
Authors: Kölliker A.
Published: April 2021

Setting out with the well-known observation of Virchow (Virch. Archiv., vol. vi., p. 133, 1853; Quart. Journ. Mic. Sci., vol. ii., p. 108), with respect to the action of caustic potass and soda on the cilia, I have in the last winter investigated their action upon the spermatic filaments. To my agreeable surprise a perfect correspondence was exhibited between these two motile bodies, except that I noticed an influence from ammonia upon the spermatic filaments, which had not been observed by Virchow in the cilia. In order to observe the action of caustic alkalies upon the spermatic filaments, the best mode of proceeding is to allow them to become perfectly quiescent in a dilute solution of sugar or of albumen, and afterwards to introduce the caustic in small quantity beneath the covering glass. It will then be seen wherever the potass or soda reaches that the mass is again put into the most lively motion, fully as active as that of the perfectly-fresh spermatozoids; but after a short time ( —1—2 minutes) a total quiescence takes place, from which the spermatic filaments cannot in any way be again roused. This phenomenon is best witnessed on the application of a solution containing from 1 to 5 parts in 100 of caustic soda or potass. In stronger solutions it undoubtedly takes place, but in this case the movement is soon over, nor does it occur in all the filaments, many of which, and especially those which first come into contact with the stream, exhibit, instead of active vibratile and locomotive movements, only a few rotations on the axis, and then become quiescent in the extended posture. Concentrated solutions of caustic alkalies, containing from 10 to 50 in 100, also produce the phenomena of revivification in a mass of quiescent spermatic filaments, and in a well-marked manner, but in this case care is still more requisite than with more dilute solutions.
On the Restoration of the Motions of the Spermatozoids of the Mammalia
Authors: Moleschott MM. , Ricchetti J. C.
Published: April 2021

The author’s researches were made on the spermatozoids of the Bull, taken in each experiment from the epididymis. These spermatozoids have a lynx-shaped head, the depression in which is small and situated towards the inferior third, and a very long tail, furnished with a minute appendicular nodosity, which is soluble in the alkalies, and is usually placed in the middle of the filament, though in some individuals it is situated nearer to the head.
Observations on aphanizomenon flos-aquæ, and a species of peridinea
Authors: Allman G. J.
Published: April 2021

The substance of the following communication has already appeared in the Proceedings of the Royal Irish Academy ; but having made some additional observations, I have thought them of sufficient interest for publication in the Microscopical Journal. The first part of the paper consists of the results of some observations made on Aphanizomenon Flos-aquœ. This minute alga has appeared in great abundance in the large pond of the Zoological Gardens, Dublin. The best account we possess of the plant is in an excellent paper on the Nostochineæ, by Mr. Ralfs ; * but as the specimens from which Mr. Ralfs’s description was drawn up were not in a recent state, some important points of structure have necessarily escaped him.
On a Post-Tertiary Lacustrine Sand, containing Diatomaceous Exuviæ, from Glenshira, near Inverary
Authors: Gregory William
Published: April 2021

This remarkable deposit was sent to me in February last by the Duke of Argyll, who had found it in the valley of Glen shira, the waters of which flow into Loch Fine, well known as a sea-loch, at its upper part. The sand occurs above a mile from the mouth of the valley, lying under a considerable depth of good alluvial soil. It is nearly black, with shining particles of mica, and very dense. It consists chiefly of the detritus of the surrounding mountains, formed of micaceous schist, and contains therefore much quartz and mica. There is also a considerable proportion of an iron ore, and of a dark matter of vegetable origin, and apparently somewhat of a peaty character. To the last-named ingredients the dark colour of the sand is due.
On the Structure of Noctiluca Miliaris
Authors: Huxley Thomas H.
Published: April 2021

Among the many striking and beautiful appearances presented by the Ocean, there is none, perhaps, which has more attracted the attention both of the naturalist and of the casual observer, than the silvery, sparkling, phosphorescent light, which may often be seen on dark nights, illuminating the track of every boat and defining the contours of the waves as they break upon the shore.
Memoir on the Coloration of the China Sea
Authors: Dareste M. Camille
Published: April 2021

We learn from the observations of M. Ehrenberg, and more recently from those of MM. E. Dupont and Montagne, that the waters of the Red Sea are, at certain epochs, coloured red by the development, in prodigious quantities, of microscopical Algæ belonging to a species described by the former of these observers under the name of Trichodesmium erythrœum.
On the Development of the Spermatozoids in Torrea Vitrea
Authors: Quatrefages M. A. de
Published: April 2021

In a memoir on the organs of sense in the Annelids (Ann. d. Sc. Nat., Зe Serie, t. xiii), I designated, under the name of Torrea vitrea, a worm remarkable for the complex nature and the development of the eyes, and the extreme transparency of the tissues. Owing to this favourable circumstance, as well as to the unusual size of the spermatogenous masses, I was enabled at once to observe in it phenomena, of which I have spoken in a note annexed to the report of Milne Edwards on the results of his travels in Sicily (Ann. d. Sc. Nat., Зe Serie, t. iii.), and concerning which I shall now enter more into detail.
On the cystolites or Calcareous Concretions in the Urticaceæ and other Plants
Authors: Weddel H. A.
Published: April 2021

About the year 1827, J. Meyen discovered in the leaves of Ficus elastica, and of several other species belonging to the same genus, certain pedunculate corpuscles, constituted, as he supposed, of gum or of some analogous substance; he ascertained that these corpuscles increased by the superposition of new layers, and that ultimately they became covered with notches and elevations composed of a calcareous, crystalline material, soluble with effervescence in acids (carbonate of lime).
Note on the Reproductive Organs of the Cheilostome Polyzoa
Authors: Huxley T. H.
Published: April 2021

Obvious as are the ovicells and partially-developed ova of the cheilostome Polyzoa, the precise position of their ovaria and testis has not yet been determined ; the general idea that the ova are developed within the ovicells being wholly an assumption. The investigation of the question is not without difficulty, on account of the delicacy of the ova in their young condition, the greater or less opacity of the ectocyst, and the obstruction offered by the other viscera if the cells be viewed in any of the positions which they ordinarily assume, lying, that is, on their front or back faces. By tearing up a polyzoarium, with needles, into single series of cells, and causing one of these series to lie upon its side, I found the process of examination much facilitated.
On an Easy Method of viewing certain of the Diatomaceæ
Authors: Hall John Charles
Published: April 2021

We shall most certainly add not a little to the chances of increasing our knowledge of the intimate structure of the infusorial tribes, if any means can be suggested by which the number of observers may be increased. Possessed of a good microscope by one of our principal makers, a student may imagine that he is in a condition at once to ascertain the exact form and nature of certain shells of Bacillaria, certainly amongst the most difficult of test objects ; a very few trials will, however, convince him that even the best-constructed eighth will not fully display their peculiar markings without some accessory instrument. For this purpose the achromatic condenser of Mr. Gillet, as made by Mr. Ross, or the achromatic condenser of Powell and Lealand, or of Smith and Beck, is usually employed. The purse, unfortunately, of the most enthusiastic labourers is not always the heaviest ; a microscope is bought and added to from time to time, and the condenser, so much coveted, must often be waited for some years.
Further observations on the genus triceratium, with descriptions and figures of new species
Authors: Brightwell T.
Published: April 2021

In June, 1853, I communicated to this Journal a paper on the genus Triceratium, with descriptions and figures of 22 species. Since that time, I have used my best endeavours to add to my knowledge of these singular forms, and have nearly doubled my list. Those not before described I purpose to describe in this paper, adding figures of each species, and shortly to notice such as other labourers in the same field have made known. I take this opportunity, also, to correct some errors in my former paper.