bluuebunny/crossref_metadata_2025_split huggingface dataset:
An approach to the thermodynamics of histological dyeing, illustrated by experiments with azure A
Authors: Goldstein D. J. 
Published: April 2021

ABSTRACT
Despite extensive quantitative work on the thermodynamics of textile dyeing (Vickerstaff, 1954), probably only Weiss (1954), who estimated the heat of reaction of elastin with orcein in vitro, has attempted to apply similar methods to a histological problem. In the present article a semi-quantitative investigation into the effect of temperature on the staining of sections by the basic dye azure A (M.W. 292) is reported, and certain aspects of the thermo- dynamics of staining are discussed. Despite the fact, discussed in the text, that some of the results reported in the present article can be accepted only with reservations, it will be shown that the thermodynamical approach to staining promises to throw light on several aspects of the staining process.
Electrophoresis of acid dyes
Authors: Byrne Jennifer M. 
Published: April 2021

ABSTRACT
Electrophoresis experiments were performed to find out whether the hydroxy- phthalein dyes which have been found to behave as basic rather than as acid dyes in their staining of phospholipid showed any signs of an amphoteric character.
It was found that it is precisely those acid dyes that stain phospholipids that show least anionic movement in electrophoresis at neutrality.
Cytochemistry of the test cells in the eggs of Pyura squamulosa (Tunicata, Pleurogonia)
Authors: Seshachar B. R. , Venkatasubba Rao S. R. 
Published: April 2021

ABSTRACT
The test cells in the eggs of Pyura squamulosa are rich in PAS-negative acid mucopolysaccharides. They also contain PAS-positive lipoproteins and other carbo- hydrate-protein-lipid complexes. The possible role of sulphated acid mucopolysac- charides in these cells is discussed.
The histochemical demonstration of haemoglobin and haemosiderin in the growing oocytes of a teleost fish
Authors: Chatterjee Nirmala 
Published: April 2021

ABSTRACT
In a previous investigation, evidence was obtained indicating the presence of erythro- cytes in the cytoplasm and germinal vesicle of a teleost fish, Trichogaster fasciatus. Histochemical tests for haemoglobin and related iron compounds have been applied to verify the histological and cytological findings. Haemoglobin (both intact in the erythrocytes and in the crystalline state) and pseudoperoxidase granules have been demonstrated histochemically both in the ooplasm and in the nucleus of immature eggs. Haemosiderins have also been detected and histochemically localized in and around the ooplasmic vacuoles.
Elementary neurosecretory granules in the neurones of the snail, Helix aspersa
Authors: Lane Nancy J. 
Published: April 2021

ABSTRACT
Elementary neurosecretory granules are present in the cytoplasm of certain neurones of the snail, Helix aspersa. The granules appear to be elaborated within the lamellae of the Golgi complex and produced at the edges of the lamellae by budding and vésiculation.
The demonstration of lysosomes in mouse skin
Authors: Diengdoh J. V. 
Published: April 2021

ABSTRACT
Lysosomes, as demonstrated biochemically in the liver, are subcellular particles containing a group of hydrolytic enzymes enclosed by a membrane-like barrier. They are apparently inactive in the normal state, but when subjected to various forms of injurious treatments the enzymes associated with them are released. The existence of lysosomes in skin is demonstrated in the present communication. The resistance of this tissue to homogenization makes the biochemical study of lysosomes very difficult. Yet, by the application of histochemical methods to sections of skin, it has been possible to use the same criteria as would be employed in the biochemical characterization of these organelles. By using the controlled-temperature freezing-sectioning method it has been possible to obtain frozen sections in which cytoplasmic particles could be demonstrated which were enzymically inactive for acid phosphatase until the sections were subjected to such injurious treatments as heat, repeated freezing and thawing, hypotonic solutions, distilled water, and ‘triton-X-100’. Since the subcellular particles demonstrated behaved in the same manner as lysosomes prepared biochemically from liver, it is concluded that the cytoplasmic organelles staining for acid phosphatase in mouse skin are lysosomes as biochemically defined.
On bridging the gap in cytology between the light and electron microscopes by some combined observations on snail neurones
Authors: McGee-Russell S. M. 
Published: April 2021

ABSTRACT
Discrepancies between observations made with the light microscope only, and with the electron microscope only, can be clarified by using both instruments to study exactly the same section of the same object. A simple technique for doing this is outlined. Direct, phase-contrast, ‘anoptral’ phase-contrast, dark-ground, interference, and ultra-violet microscopy can all be used. When applied to snail neurones this technique of combined observations reveals intracellular organelles which have not previously been differentiated. These organelles are positively identified by criteria appropriate to each instrument. By combined observations it is possible to see the ‘Golgi apparatus’ in preparations stained only with Nile blue, by direct microscopy. Data obtained by combined observations are considered in relation to the previous literature. Unequivocal cross-correlations between the light and the electron microscope go a long way towards explaining past difficulties.
Experiments on embedding media for electron microscopy
Authors: McGee-Russell S. M. , De Bruijn W. C. 
Published: April 2021

ABSTRACT
Experiments were conducted to determine the feasibility of improving the trimming and sectioning properties of the polymers glycol methacrylate (Rosenberg, Bartl and Leško,1960) and durcupan (X133/1097) (Stäubli, 1960) by combining them with other resins, in particular epon 812. We have also attempted to determine the value of comparative studies of tissue given different fixation and dehydration treatments, prior to embedding in the same final embedding medium.
Presumed photoreceptive cilia in a ctenophore
Authors: Horridge G. A. 
Published: April 2021

ABSTRACT
Four groups of lamellate bodies are symmetrically arranged inter-radially in the floor of the apical organ. Each is composed of many streamed-out membranes of a group of about a dozen cilia, within an invagination of a cell. The rings of ciliary fibrils, of the 9 + 0 pattern, become disarrayed not far from the base. Their dense membranes are lined with granules so that the successive lamellae resemble those of the modified cilia of vertebrate eyes, although flattened in a different plane. On this basis, of ciliary origin, and their resemblance to photoreceptors in fine detail, these structures are interpreted as photoreceptors.
Acid phosphatase activity in the neutral red granules of mouse exocrine pancreas cells
Authors: Byrne Jennifer M. 
Published: April 2021

ABSTRACT
The Gomori test for acid phosphatase was performed on pancreatic tissue from mice injected with neutral red. On an electron microscopical level, acid phosphatase activity was found to be localized in the neutral red granules.
It is suggested that the neutral red granules are of lysosomal derivation.
The yolk nucleus of fish oocytes
Authors: Nayyar R. P. 
Published: April 2021

ABSTRACT
A comparative study of the yolk nucleus in the oocytes from 8 species of fishes has been carried out. The yolk nucleus appears as a mass of lipid granules and mitochondria situated beside the nucleus. It becomes spherical, detaches itself from the nucleus, and migrates to the peripheral region of the cytoplasm to lie just below the cell membrane. During the migration, the lipid granules of the yolk nucleus grow and move out of this organelle. When the oocyte is about 180/x in diameter, the yolk nucleus breaks up and its components are dispersed in the cytoplasm. No differences have been found in the morphology of the yolk nucleus in the species under investi- gation.
Two more accessories for the Huxley ultramicrotome
Authors: Mcgee-Russell S. M. , Smale C. J. G. , Banbury W. 
Published: April 2021

ABSTRACT
A combined section-mounting stage and miniature hot plate has been made to be used with the Huxley ultramicrotome. It facilitates precision in the handling of 0·2 to 2 μ sections during mounting and staining for light microscopy. Both processes can be carried out under continuous binocular magnification.
The advance mechanism of the microtome has been fitted with a simple bell circuit to give an audible signal at the beginning and end of the full travel of the mechanical advance. This signal may be calibrated by readings on the vernier advance of the knife holder, for re-setting the microtome on a given block face. During prolonged bouts of sectioning the audible signal is a useful warning of full extension of the advance mechanism.
The connective tissue sheath of the locust nervous system: its development in the embryo
Authors: Ashhurst Doreen E. 
Published: April 2021

ABSTRACTThe embryological development of the connective tissue sheath around the nervous system has been investigated in Schistocerca gregaria. The sheath cells appear to be derived from outlying ganglion cells. The neural lamella is first visible when the embryo is 9 days old and it increases in thickness until hatching occurs on the twelfth day. It is produced entirely by the sheath cells.The sheath cells have numerous lipid droplets in their cytoplasm. Some neutral mucopolysaccharide and proteins are also present. The histochemical reactions of the neural lamella after its formation suggest that it is composed of collagenous proteins embedded in neutral mucopolysaccharides.The sheath cells are typical fibroblasts during the formation of the neural lamella. The cisternae of the endoplasmic reticulum are dilated into vesicles which contain a somewhat electron-dense material. No intracellular fibrils were observed. Collagen fibrils with banding of periodicity between 55 and 60 mμ are seen in the neural lamella from 11 days onwards.
The Distribution of Alkaline Phosphatase in the Skull of the Developing Trout
Authors: Lorch I. Joan 
Published: April 2021

ABSTRACT
The histological and cytological distribution of alkaline phosphatase in developing trout has been studied with special reference to membrane and cartilage bone formation in the skull. Nuclear phosphatase is widely distributed in the youngest stages examined, but decreases as differentiation proceeds. Extracellular phosphatase is always associated with ossification or fibre formation. No deposition of calcium salts in the absence of phosphatase was observed. Alkaline phosphatase is probably connected with histogenesis in general apart from its special function in calcification.
The Shell in the Lamellibranchia
Authors: Owen G. 
Published: April 2021

ABSTRACT
I. In the Lamellibranchia, the direction of growth at any region of the valve margins may be resolved into : (a) a radial component radiating from the umbo and acting in the plane of the generating curve ; (b) a transverse component acting at right angles to the plane of the generating curve; (c) a tangential component acting tangentially to, and in the plane of, the generating curve. The radial component is always present and affects the form of both valves while the transverse component may be reduced or absent in one valve.
2. The lamellibranch mantle/shell is orientated with reference to the normal axis. This normal axis follows that sector of the shell secreted by the normal zone of the mantle edge (i.e. where the effect of the transverse component is greatest) and passes through the umbo, the normal zone and the point at which the greatest transverse diameter of the shell intersects the surface of the valves.
3. The form of the shell valves should be considered with reference to : (a) the outline of the generating curve; (b) the spiral angle of the normal axis; (c) the form (i.e. pianospiral or turbinate spiral) of the normal axis.
4. The ‘deflection’ anteriorly of the umbones and the splitting of the anterior portion of the ligament in many bivalves is a consequence of a tangential component affecting the form of the valves.
5. In both gastropods and lamellibranchs, the turbinate spiral shell is the resultant of two differential growth ratios. In the Gastropoda, however, both ratios act perpendicularly to the plane of the generating curve, while in the Lamellibranchia, one acts perpendicularly to this plane while the other acts in the plane of the generating curve.
A Histological Study of the Development of the Scales of the Largemouth Black Bass (Micropterus salmoides)
Authors: Dietrich Mary Alice 
Published: April 2021

ABSTRACT
1. The scale method of age determination in largemouth black bass, Micropterus salmoides, is valid at least up to and probably including the third year of the fish’s life. A more careful study of older fish might reveal that it was valid beyond that point.
2. The annulus in a largemouth black bass is formed by a brief but gradual slowing down of growth and then its quick resumption. The annulus appears as a wide band on the anterior edge of the scale, and as a dark line (circulus) cutting across some inner dark lines (also circuit) on the lateral edges.
3. The scale is mesodermal in origin, and lies in a pocket surrounded by dermal tissue, which in turn is covered externally by a thin layer of epidermis.
4. The bony layer is formed by osteoblastic cells on its outer surface in a manner similar to the formation of dermal bone. Excess bony material is accumulated in ridges or circuli.
5. The fibrillary plate is formed by the fibroblastic cells on its inner surface.
Nematocysts of Corynactis: The Activity of the Filament during Discharge
Authors: Robson E. A. 
Published: April 2021

ABSTRACT
1. The appearance of one type of nematocyst from Corynactis before, during, and after discharge is described. Discharge is a progressive eversion of the intracapsular filament.
2. Weill’s observation that the speed at which dried nematocysts can be made to discharge depends on the quantity of water available is confirmed.
3. In water, dry isolated fragments of undischarged filament undergo changes in size which normally accompany discharge, while remaining uneverted. This reaction is an anisometric swelling of the shaft wall due to water absorption, and is largely responsible for the normal progression of discharge in nematocysts.
4. Electron microscopy has been used to investigate the morphology of various nematocysts.
Observations on Substances that react weakly to the Periodic Acid/Schiff Test
Authors: Hale Arthur J. 
Published: April 2021

ABSTRACT
It has been shown that certain mucinous substances which are weakly positive with the periodic acid/Schiff technique stain more strongly after treating them with a solution of sodium hydroxide.
The deepening of the staining reaction is produced by making available, for aldehyde production by periodic acid, more .CHOH.CHOH., . CHOH. CHNH2., or . CHOH .CHNHR. groups. This is done without affecting those sulphate or metaphosphate groups responsible for metachromasia.
The Lipoid Contents of the Golgi Bodies in the Oocytes of the Indian Water Spider, Lycosa birmanica
Authors: Krishna Daya 
Published: April 2021

ABSTRACT
1. The Golgi bodies of the oocyte of Lycosa birmanica do not contain triglyceride.
2. They contain phospholipine, lipo-protein, and protein.
3. They are granular and all of approximately equal size. Any variation in their size or shape is due to the irregular deposition of phospholipine on them.
4. Fine bodies resembling Golgi bodies in appearance and reacting like them with osmium tetroxide and silver nitrate consist of phospholipine.
5. The Golgi bodies in the material studied appear not to multiply by division, but to arise in the ground cytoplasm independently of one another. They may be regarded as nutritive bodies.
The Cell-theory: a Restatement, History, and Critique: Part IV. The Multiplication of Cells
Authors: Baker John R. 
Published: April 2021

ABSTRACT
In the first half of the nineteenth century it was commonly supposed that new cells arose either exogenously, outside pre-existing cells, or endogenously, from small rudiments that appeared within pre-existing cells and gradually grew larger. The theory of exogeny had been founded by Wolff (1759), and was supported especially by Link (1807), Schwann (1839), and Vogt (1842). The theory of endogeny, which had been hinted at by various writers in early times, obtained the backing of a very large literature. Its chief advocates were Raspail (1825, &c.), Turpin (1827, &c.), Schleiden (1838), Kôlliker (1843-4), and Goodsir (1845).
That cells do not arise exogenously or endogenously, but are produced by the division of pre-existing cells, was at last realized by the convergence of studies made in three separate fields, as follows :
(1) Trembley (1746, &c.), Morren (1830, 1836), Ehrenberg (1830, 1832, 1838), and others noticed how protists multiply.
(2) Dumortier (1832), Mohl (1837), and Meyen (1838) watched the partitioning of the cells of filamentous algae.
(3) Several observers studied the cleavage of eggs and at last revealed that this was a process of cell-division (Prévost and Dumas (1824), von Siebold (1837), Barry (1839), Reichert (1840), Bagge (1841), Bergmann (1841-2)).
Nàgeli (1844, 1846) also made an important study of cell-division in all the main groups of plants (except bacteria), but used an unfortunate nomenclature that tended to obscure the true nature of the process.
Remak (1852 and 1855) and Virchow (1852, 1855, 1859) made general statements to the effect that division is the standard method by which cells multiply. The writings of Remak on this subject were much more weighty than those of Virchow.
Physical Factors involved in the Vertical Migration of Plankton
Authors: Harris John E. 
Published: April 2021

ABSTRACT
It is suggested that vertical migration is an inescapable consequence of the use of light by planktonic forms as a means of attaining a level within the euphotic zone; no other sense organ appears capable of producing this result. The mechanism of light response in Daphnia fulfils the necessary requirements for vertical migration, and field observations on other species suggest the presence of similar if not identical physiological features in them. These features are a positive photokinesis which is combined with negative geotaxis at low light intensities; at a critical higher value of light intensity a typical dorsal light reflex cuts off the vertical rise. The dorsal light reflex is probably a response to illumination of the eye within the critical cone of submarine illumination, and is therefore not related to the direction of a particular light source such as the sun.
Histological and Polarization Studies of the Brush Border of the Proximal Convoluted Tubules of the Rat Kidney
Authors: Brewer Douglas B. 
Published: April 2021

ABSTRACT
The kidneys of rats were examined histologically after the intraperitoneal injection of haemoglobin and also after the intrarenal injection of a graphite suspension. During haemoglobin excretion spaces can be seen running across the brush border of the proximal convoluted tubules. These spaces are filled by the reabsorbed haemoglobin passing from the tubular lumen into tbe.tubular cells. After intratubular injection of a graphite suspension, particles about 0·5 μ diameter cross the border and appear in the cell cytoplasm.
Examination with the polarizing microscope shows the brush border to have positive form and negative intrinsic birefringence with respect to the length of the striations.
These findings are considered in relation to the appearances found on electron microscopy. It is suggested that on present evidence it is most likely that the brush border consists of rodlets of the order of 300–600 Å diameter, with an orientated molecular structure at right angles to their length. These rodlets are gathered in tufts so that they diverge from one another. The spaces between the tufts at their bases is about 0·3–0·5 μ and at their tips they just touch one another.
The Deposition of the Third Instar Larval Cuticle of Calliphora erythrocephala
Authors: Wolfe L. S. 
Published: April 2021

ABSTRACT
A histological study has been made of the formation of the cuticle of the third instar of Calliphora.
Increase in size of the epidermal cells and nuclei, particularly in the spiny regions, preceded the release of the moulting fluid. The cytoplasm first became vacuolated and this was followed by the appearance of many granules. The basement membrane is constituted in part by stellate tracheoblast cells. The membrane breaks down just before cuticle deposition and reappears after ecdysis.
The outer epicuticle is formed from coalesced droplets aligned at the cell surface to form a delicate continuous, folded, acidophil, lipoprotein layer. Further, protein and lipoid (cuticulin) is added beneath this layer from cytoplasmic processes to form the inner epicuticle. These processes later became the pore canals. Endocuticle is secreted as filaments from the epidermal cells between and around the processes.
During moulting, phenolic substances and oxidase are transported to the inner epicuticle only in the cuticular spines. Wax and cement layers are not formed and there are no dermal glands.
The peak in the secretory cycle of the oenocytes corresponds to the time of deposition of the epicuticle and the secretory material shows similar staining properties to epicuticular material. The oenocyte groups are connected with each other and with the epidermis by cytoplasmic extensions, through which secretory granules pass.
The muscle insertions are not attacked by the moulting fluid. They are thought to contain protein-bound sulphur. The separation of the muscle insertions and sensory organs from the exuvial cuticle occurs just before ecdysis.
The nature of the epicuticle and the theory that the oenocytes are associated with its formation is discussed.
A Plastic Lacquer Substitute for Coverslips
Authors: Perry J. S. 
Published: April 2021

ABSTRACT
A plastic lacquer manufactured by Cellon Ltd. has been found useful for covering sections on glass slides of any size.
It takes the place of both mounting medium and coverglass and saves storage-space. The method has proved particularly valuable in mounting large series of sections and serial sections of large specimens. Its use in conjunction with bulk staining techniques is described. The lacquer is very clear and has not been found to deteriorate on the slide after several years.
The Thickness of the Cortex of the Sea-Urchin Egg and the Problem of the Vitelline Membrane
Authors: Mitchison J. M. 
Published: April 2021

ABSTRACT
The gelated cortex of a sea-urchin egg can be seen as a granular layer at the edge of the hyaline zone in a centrifuged egg. Measurements were made of the thickness of this layer in the eggs of Paracentrotus lividus and Arbacia lixula at various stages of development from the unfertilized egg to the first cleavage. The thickness was roughly 2 μ in living eggs, and 1 · 15 – 1 · 35 μ in sections of fixed eggs. There were no appreciable changes in the thickness up to the first cleavage, and it is concluded that a value of 1 · 5 μ can be taken as an approximate figure for all stages.
The cortex is usually invisible in normal eggs either living or in section, but in the case of sections of fertilized Arbacia eggs it can be seen as a vacuolated layer. The thickness of this layer was found to be 1 · 13 μ at the sperm aster stage and 1 · 50 μ at cleavage. In these eggs at cleavage, there were no signs either of differences in thickness at different regions of the surface or of a differentiated region of the cytoplasm ahead of the furrow.
There were no clear indications of the presence of a vitelline membrane either in living or fixed eggs.
A layer about 0 · 8 μ thick, pale with iron haematoxylin, was found at the edge of sections of unfertilized eggs which had been fixed in Bouin, but not with those which had been fixed in Flemming. This is probably the outer layer of the cortex which normally contains the cortical granules.