bluuebunny/crossref_metadata_2025_split huggingface dataset:
CARBON SURFACE REPLICAS FOR ELECTRON MICROSCOPY AND ELECTRON DIFFRACTION
Authors: Scott D. B. , Wyckoff R. W. G. 
Published: November 2011

SYNOPSISA technique is described for using evaporated carbon films in the preparation of pseudo‐replicas that can be employed for both electron microscopy and electron diffraction. The areas selected microscopically for diffraction can be as small as one square micron. Fluorescent X‐ray analyses can frequently be carried out on the same preparations.The procedure is illustrated from current investigations of tooth enamel and with pseudo‐replicas from a variety of other solids.
NOTES ON MULTIPLE IMAGE FORMATION BY AEROSOL PARTICLES AT SUBMERGED BUBBLE SURFACES, AND ITS RELEVANCE TO A SURFACE FILM
Authors: Gardiner M. W. 
Published: November 2011

SYNOPSISRadial striations are shown to be present as fixed appearances in the refraction rings of submerged bubbles in diverse media, and to be due to aerosol particles at the surface. They are shown to be of multiple origin, being composed of brighter parts of concentric rings of light which may be produced in this usually dark zone. Possible causes of these phenomena are discussed in relation to the bubble surface. It is concluded that the bubbles are surrounded by thin layers of static material of different refractive index from the bulk of the liquid, and that the “radial striations” are due to multiple image formation by the two interfaces produced.
ELECTRON MICROSCOPE STUDIES ON DIATOMS
Authors: Desikachary T. V. 
Published: November 2011

SYNOPSISA review of the electron microscopy of diatom wall structure is given. The structure of the areolæ and its variations are described. The diatoms are divided into nine groups based on their wall structure. The structures of the mucilage pores, spines and the raphe are described from the electron microscopic studies.As many as 80 genera and nearly 300 species have been investigated by different workers. A full list of these is given and the facts known about them analysed.The writer supports the view that structural details revealed by electron microscopy have a definite place in taxonomy.
AN EXAMINATION OF THE SCALES AND BRISTLES OF MALLOMONAS IN THE ELECTRON MICROSCOPE USING CARBON REPLICAS
Authors: Harris Katharine , Bradley D. E. 
Published: November 2011

SYNOPSISThe species of the genus Mallomonas, classed amongst the algæ, are small cells covered with characteristic silica scales and bristles. These are of considerable importance in the classification of the species, but only the coarser details are visible under the optical microscope. A direct electron microscope study yields much information about the fine markings on the scales, but the use of carbon replicas produces clearer, more easily interpreted micrographs, and permits the examination of the exterior of a complete organism.The scales and bristles of nine species, three of which are new, are described, and some variations in the markings within a single species are illustrated.
THE MORPHOLOGY OF BOAR SPERMATOZOA
Authors: Hancock J. L. 
Published: November 2011

SYNOPSISThe morphological features of boar spermatozoa in freshly ejaculated semen and in semen exposed to various experimental treatments have been studied in stained smears and with the phase‐contrast microscope and the electron‐microscope.The spermatozoon of the boar closely resembles that of other domestic ungulates. The head is approximately 8.5μ long; it is twice as long as it is wide. The mid‐piece is approximately 10μ long and the main tail‐piece is 30μ long.The head is covered anteriorly by a cap‐like structure—the acrosome. Evidence is presented to show that the acrosome has two components: the outer acrosome is the larger, the smaller inner acrosome is a crescentic structure. The segment‐shaped area of overlap between the two parts of the acrosome forms the equatorial segment which is a feature of living boar spermatozoa.The surface of the head behind the acrosome impregnates with silver; this argentophil area is the post‐nuclear cap.Three neck granules can be distinguished at the posterior border of the head and these are apparently connected to three bundles of neck fibres which the head receives from the mid‐piece.The structure of the spermatozoon is altered by post‐mortem changes; the most prominent changes occur in the acrosome. Evidence is presented that the post‐nuclear cap is absent from dead spermatozoa.The development of the boar acrosome has been studied in sections stained by the PAS method and in unfixed tissues with the phase‐contrast microscope. The development of the post‐nuclear cap has been studied in sections impregnated with silver. The morphological features of epididymal spermatozoa have been studied in spermatozoa from different levels of the epididymis.The development of the acrosome is shown to resemble its development in the bull. Two separate components of the acrosome of the spermatid are distinguished. It is suggested that these develop into the two components of the acrosome of the mature spermatozoon.Migration of the cytoplasmic droplet from the neck to the mid‐piece occurs at varying levels in the epididymis, but it is shown that it may occur in the head of the epididymis.The findings are discussed in relation to current ideas about the structure of mammalian spermatozoa.
APPLICATIONS OF AN EPOXIDE EMBEDDING MEDIUM TO ELECTRON MICROSCOPY
Authors: Birbeck M. S. C. , Mercer E. H. 
Published: November 2011

SYNOPSISThe Araldite embedding resin, described by Glauert et al., for preparing thin sections for electron microscopy has been tried on a wide range of materials and found to prevent completely the “explosion damage” so common with methacrylate polymers.
A STUDY OF FRESH MOUSE ASCITES TUMOUR CELLS BY ULTRA‐VIOLET, PHASE‐CONTRAST AND INTERFERENCE MICROSCOPY
Authors: King R. J. , Roe E. M. F. 
Published: November 2011

SYNOPSISVarious microscopical techniques have been used to study the morphology of ascites tumour cells. These methods have the advantage that they are applicable to fresh material, thus avoiding the artefacts usually caused by fixation and associated procedures. Certain observations concerning the distribution of nucleic acids and proteins within these cells are discussed.
IV.— THE OPTICAL CORRECTION OF OBJECTIVES USED FOR MICROSPECTROSCOPY
Authors: KING R. J. 
Published: November 2011

SYNOPSISThe optical densities of small absorbing particles have been measured, initially with the microscope system well corrected optically and then after the introduction of spherical aberration by variation of the immersion fluid refractive index. It was found that several times the Rayleigh limit of spherical aberration could be tolerated without affecting the accuracy of the results, provided the condenser aperture was kept considerably smaller than the objective numerical aperture, this being a necessary condition from other considerations. There was, moreover, a surprisingly small deterioration of image quality. The effects on absorption measurements caused by the presence of coma and central obscuration in the microscope objective are also discussed.
ELECTRON MICROSCOPE STUDIES OF NEW ZEALAND MARINE PLANKTON DIATOMS*
Authors: Cassie Vivienne , Bertaud W. S. 
Published: November 2011

SYNOPSISA description is given of the fine structure of two marine plankton diatoms from New Zealand: Stepkanopyxis orbicularis Wood and Biddulphia mobiliensis (Bailey) Grunow. Three‐dimensional structure has been elucidated by photogrammetric means from stereoscopic pairs of electron micrographs.A hypothesis regarding the mechanism of growth in the girdle of Stephanopyxis is suggested.
THE MITOCHONDRIA DURING THE DIFFERENTIATION AND GROWTH OF THE NERVE CELLS OF SCHISTOCERCA GREGARIA
Authors: Moussa Tohamy A. , Banhawy M. 
Published: November 2011

SYNOPSISThe mitochondria occur as granules and short rods throughout the various developmental stages of the locust. No filamentous mitochondria could be detected. In early germ‐band cells the mitochondria exist as small granules and very short rods scattered in the cytoplasm. They are shared out between the dividing neuroblasts, and remain as such in the early ganglion cells and in the first four nymphal instars.The nerve cells of the fifth instar nymph (as well as the large neurones of the fourth instar nymph) and adult locust contain, besides the normal mitochondria, a number of swollen bodies which we consider as metamorphosed mitochondria. The latter type, in old neurones, decreases in number and moves towards the cell periphery.In the senile condition the metamorphosed mitochondria are no longer visible.The pictures of mitochondria in living unstained or vitally stained preparations do not differ from those of fixed and stained materials.The mitochondria are not responsible for the production of the Golgi dictyosomes as an effect of fixation and metallic impregnation, as is shown from the following:

In the early germ‐band cells, a single osmiophilic globule (Golgi body) is found, whereas the mitochondria appear in the form of many small granules and very short rods scattered in the cytoplasm.
In the early developmental stages, the mitochondria are evenly scattered in the cytoplasm, whereas the Golgi dictyosomes are polarized.
The mitochondria and dictyosomes can be demonstrated side by side in the same cell.
NOTES ON THE HISTOLOGY AND ANATOMY OF THE LARVA OF BOLITOPHILA LUMINOSA OF NEW ZEALAND
Authors: Ganguly Gouri 
Published: November 2011

SYNOPSISThe histology and fine anatomy of the larva of Bolitophila luminosa have been considered. There are two separate glands, silk (salivary) and mucus, producing the web and mucus droplets of the snare. Chordotonal (scolophore) organs have been described from the anal papillæ.
THE VISCERAL HISTOLOGY OF THE PRIMITIVE CETACEAN CAPEREA (NEOBALAENA)
Authors: Cave A. J. E. , Aumonier F. J. 
Published: November 2011

SYNOPSISThe histology is described, for the first time, of the liver, kidney, and heart muscle of the rare and primitive cetacean Caperea (Neobalœna) marginata Gray, 1844. Observations are also submitted on the hepatic histology of Physeter catodon, Megaptera novœangliœ and Lagenorhynchus cruciger, and a tentative hypothesis is advanced concerning the mode of venous drainage of the cetacean liver lobule. Attention is drawn to a hitherto undescribed histological feature of the kidney of Caperea, Physeter, Phocœna and Lagenorhynchus, and its interpretation is attempted in terms of renal structure and function.
A FURTHER CONTRIBUTION TO OUR KNOWLEDGE OF PHLYCTOCHYTRIUM UNISPINUM PATERSON
Authors: Willoughby L. G. , Townley Patricia J. 
Published: November 2011

SYNOPSISThe fungus Phlyctochytrium unispinum Paterson (Phycomycetes, Chytridiales) previously known only from the U.S.A., is described from Great Britain for the first time. Using British material, a further contribution has been made to knowledge of this chytrid.
COCCOLITHS AND DISCOASTERS FROM THE FLOOR OF THE SOUTH ATLANTIC OCEAN
Authors: Black Maurice , Barnes Barbara 
Published: November 2011

SYNOPSISThe minute structure of the coccoliths borne by several species of Chrysophyceæ is described and illustrated by electron‐micrographs of carbon replicas. The use of replicas enables anatomical details which are obscure or invisible in micrographs of the object itself to be seen clearly, and they provide a means of distinguishing with certainty between species which have very small coccoliths of similar gross appearance but different in their plan of construction.
QUANTITATIVE STUDIES ON LIVING CELL INCLUSIONS
Authors: Ross K. F. A. 
Published: November 2011

SYNOPSISThe purpose of this paper is to show that refractive‐index measurements made by interference microscopes can provide much varied and interesting information about many of the visible constituents of living cells, and consequently about the cells as a whole.There are two main methods of measuring the refractive indices of cytoplasmic inclusions in living cells; by immersing the cells in non‐toxic isotonic mounting media with the same refractive index as their cytoplasm, and by compressing the cells to a determined thickness. Both these methods, which can under certain circumstances also be applied to measuring the refractive indices of nuclear inclusions, are described in detail.Usually, refractive‐index measurements made on an inclusion in a living cell are used to indicate the percentage of total solid and water present in that region, but, in addition, they can sometimes provide information about its submicroscopic molecular arrangement, its histochemical nature, and its permeability properties; and examples of all these interpretations are described.
FLUORESCENCE MICROSCOPY OF MOUSE BONE‐MARROW CELLS
Authors: Ashwood‐Smith M. J. , Young M. R. 
Published: November 2011

SYNOPSISMouse bone‐marrow cells have been treated with a 1:20,000 concentration of acridine‐orange and mounted on slides coated with nutrient agar. Under these conditions cells spread themselves rapidly, and active movements can be observed within a few minutes. When viewed with blue‐violet light a variety of marrow cells can be distinguished. The nuclei fluoresce green and the cytoplasmic granules fluoresce red; this cytoplasmic granulation is similar to that observed with phase‐contrast microscopy. Photographs were obtained using Ektachrome high‐speed colour film which permitted greatly reduced exposure times. Black and white bromide prints made from colour transparencies could be made without difficulty. These have the advantage of being free from grain.
THE CELLULAR UPTAKE OF PROTEINS LABELLED WITH FLUORESCENT DYES
Authors: Cormack D. H. , Ambrose E. J. 
Published: November 2011

SYNOPSISThe use of the direct fluorescent‐labelling technique as a method for demonstrating the uptake of proteins by living cells is evaluated. This technique has been applied to the uptake of wheat‐germ “lipase” and insulin by a selection of normal and malignant cell types. Some enzymatic activity of the “lipase”, which shows aliesterase activity, has been shown to remain after the labelling procedure. It was taken up in relatively large amounts by pinocytosis, and accumulated on the cell membrane of normal cells. Insulin did not appear to be taken up by pinocytosis.
ELECTRON MICROSCOPE OBSERVATIONS ON THE PHALLIC (CONGLOBATE) GLAND OF THE COCKROACH, PERIPLANETA AMERICANA
Authors: Beams H. W. , Anderson Everett , Kessel Richard 
Published: November 2011

SYNOPSISThe lumen of the phallic gland is lined by a layer of cuticle derived from an invagination of the integument. The same layers as found in the integument are represented in the cuticular lining; namely, epicuticle, exocuticle, and endocuticle with an underlying epidermal layer. In sections through the cuticle and the underlying gland cells, small ductules are seen to penetrate the cuticular layer and extend to the surface of the gland cells where they enter them and become continuous with small intra‐cellular ductules. Upon entering the gland cell a marked change in the structure of the ductule occurs. This consists in the termination of the relatively dense, continuous epicuticle as such and the appearance of a highly reticulated layer which extends throughout the remainder of the ductule. Abutting upon the reticulated layer are the microvilli. Small vesicles are often observed in the outer border of the cell. These may serve as a transport system.Mitochondria and relative large secretion bodies are frequently concentrated below and near the base of the microvilli. The Gogli material is present in the form of dictyosomes and the ergastoplasm as numerous rosettes, groups of small ribosomes or as vesicular elements.
A SURVEY OF EMBEDDING MEDIA FOR ELECTRON MICROSCOPY
Authors: Glauert Audrey M. 
Published: November 2011

SYNOPSISThe survey describes the various embedding media that are now available for thin sectioning and electron microscopy, with the aim of aiding a correct choice of medium in any particular investigation. The properties of the methacrylates, the epoxy resins and the polyester resins are compared and, in particular, the basic similarities between the different mixtures containing epoxy resins are emphasized. A description of water‐soluble embedding media is included.
THE SIZE OF BACTERIA, AS MEASURED WITH THE DYSON IMAGE‐SPLITTING EYEPIECE
Authors: Powell E. O. , Errington F. P. 
Published: November 2011

SYNOPSISUsing the Dyson image‐splitting eyepiece, a careful unfatigued observer can measure the dimensions of a bacterium with a standard deviation of about 0.03 μ. Systematic as well as random errors are discussed. The application of the eyepiece is illustrated by a number of specialized examples, including the growth of individual bacteria.
DIRECT EHRLICH ASCITES TUMOUR CELL DIAMETER MEASUREMENTS BY PROJECTION OF A MICROSCOPE IMAGE
Authors: Barker N. , Needham George H. , Furst Arthur 
Published: November 2011

SYNOPSISThe carcinostatic action of phenazine‐di‐N‐oxide against the Ehrlich tumour was subjected to closer study on individual cells. A method was devised whereby the increase in cell diameter could be followed by direct measurement on the projected microscope image. After standardization of the optics so that 1 μ on the slide equalled 1 mm on the ruler, 50 cells per 20 minutes could be measured randomly.Observations 24 hours after drug administration into a mouse bearing a 7‐day tumour showed that treated cell diameters increased from a median diameter of 14 μ to a median of 21 μ (many had doubled in size) as compared to an increase of 1.9 μ in the controls. After 72 hours the treated cells reached a maximum diameter and disintegrated. By this time there was an absence of ascitic fluid. The drug acted by accelerating the growth and exaggerating the disordered mitoses of the tumour cells which were unable to cleave daughter cells, leaving a cluster of partially divided protuberances.
THE USE OF WATER‐SOLUBLE GLYCOL METHACRYLATE IN ULTRASTRUCTURAL CYTOCHEMISTRY
Authors: Leduc Elizabeth , Marinozzi V. , Bernhard W. 
Published: November 2011

SYNOPSISA procedure for the application of cytochemical techniques directly on ultrathin sections for electron microscopy has been developed with the use of water‐soluble plastics, which act both as dehydrating agents and embedding media. Our approach has been to selectively extract proteins and nucleic acids from ultrathin sections of cells and viruses by specific enzyme hydrolysis. Glycol methacrylate is particularly useful as a component of the embedding medium because it enhances the penetrability of the enzyme into the section and preserves the biological materials in such a way that they remain susceptible to enzymic digestion. Various degrees of morphological preservation of ultrastructure are obtained with the aldehyde fixatives, formalin, acrplein, and glutaraldehyde, followed by. embedding in glycol methacrylate and the choice of fixative, at present, depends on the system which is to be studied. It is believed that the proposed method can be developed further and be used for other approaches to ultrastructural cytochemistry.
AN ADHESION TECHNIQUE FOR SMALL AQUATIC ORGANISMS
Authors: Hawes R. S. J. 
Published: November 2011

It is a recognized difficulty in making permanent preparations of small aquatic organisms, or of those cultivated in aqueous solutions, that they must either be stained in bulk, when the control of differentiation is uncertain, or they must be attached to slides or cover‐slips, when they may be stained and differentiated as precisely as sections. The latter method is plainly preferable, especially for cytological work, but its application is commonly unreliable, in that specimens are lost or distorted at one stage or another, or it is successful only in experienced hands on a limited range of material. The following technique has the advantages that slides holding many thousands of specimens may be prepared without loss or, provided that fixation has been good in the first place, distortion. It has been applied in this laboratory almost exclusively to Protozoa, including such notoriously difficult subjects as flagellates from fresh water or aqueous culture solutions, but it is equally successful with small metazoan animals such as rotifers and gastrotrichs.The principle is to concentrate the material after fixation, washing, and dehydration, soak it in a thin solution of celloidin and allow drops of this to spread on slides. The film of celloidin containing the organisms adheres to the slide, which is thereafter treated as if it carried a section, except that precautions must be taken against the tendency of celloidin to dissolve in the higher alcohols.
Ultrastructure of mercerized cotton fibres*
Authors: ROLLINS MARY L. , MOORE ANNA T. , DEGRUY INES V. , GOYNES WILTON R. 
Published: November 2011

SYNOPSISSome changes in the structure of cotton fibre which accompany mercerization are illustrated. The familiar swelling, rounding out, and partial untwisting of the collapsed fibre into a more nearly rod‐like shape have been investigated with both the light and the electron microscope. Shrinkage and compacting of the primary‐wall network to provide a constricting casing about the fibre, crimping of the microfibrils of the secondary‐wall cellulose, and ultimate smoothing out of the wrinkled primary wall have been observed. A technique for expansion of the fibre wall into layers further demonstrates the altered structure of the cotton fibre after tension‐mercerization.
Electron microscopy of a porcine adenovirus
Authors: CHANDLER R. L. , HAIG D. A. , SMITH K. 
Published: November 2011

SYNOPSISA virus isolated from the pig and showing characteristics of an adenovirus has been examined by electron microscopy in both the purified state and in tissue culture cells. The virus is icosahedral in shape, has 252 capsomeres per capsid, and is characteristic of the adenovirus group. Examination of infected cells shows that the virus is predominantly intranuclear but virus has also been demonstrated in the cytoplasm. The cellular relationships characterise the adenovirus as more likely to be a member of the sub‐group containing types 3, 4 and 7 than that containing type 5. The virus is closely associated with the chromatin of the nucleus, in which parallel densely staining fibres have been demonstrated. Other structures with a rectilinear profile have been observed which have dense cores, evidence of a helical component and loci resembling the spheroidal form of virus.The first report of the isolation from a pig of a virus resembling an adenovirus was made by Haig et al. (1946): the results of serological tests indicated that the virus possessed the adenovirus group antigen but there was no neutralisation against several of the commoner human adenoviruses; the cytopathic changes in tissue culture were of the type described for the sub‐group of human adenoviruses types 3, 4 and 7. This paper records an electron‐microscope study of the morphology of the virus, the changes in infected tissue‐culture cells and the micro‐ecology of the virus.
Cytochemical studies on the non‐specific esterases of the rat ovary
Authors: BULMER D. 
Published: November 2011

SYNOPSISThe indoxyl and naphthol AS techniques, used in association with Mipafox and E600, indicate the presence of both organophosphate‐sensitive and organophosphate‐resistant esterases in the rat ovary. Organophosphate‐sensitive type B enzymes occur in the theca interna and interstitial cells; a B‐esterase activity is particularly prominent in the corpus luteum of pregnancy. The organophosphate‐resistant type C enzymes are demonstrated in macrophages, interstitial cells, theca interna, germinal epithelium and granulosa cells of atretic follicles. In corpora lutea the C‐esterase activity increases with the ageing and degeneration of the luteal cells. The distribution of organophosphate‐resistant esterase is very similar to that of acid phosphatase and the high content of these lysosomal enzymes in the ovary may be an important factor in its responses to hormonal stimuli.